Issue |
A&A
Volume 520, September-October 2010
|
|
---|---|---|
Article Number | A109 | |
Number of page(s) | 74 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361/200913262 | |
Published online | 12 October 2010 |
Internal kinematics of spiral galaxies in distant clusters
IV. Gas kinematics of spiral galaxies in
intermediate redshift clusters and in the field
,![[*]](/icons/foot_motif.png)
E. Kutdemir1,2 - B. L. Ziegler2 - R. F. Peletier1 - C. Da Rocha2,3 - A. Böhm4 - M. Verdugo5
1 - Kapteyn Astronomical Institute, PO BOX 800, 9700 AV Groningen, The
Netherlands
2 - European-Southern Observatory, Karl-Schwarzschild Str. 2, 85748
Garching, Germany
3 - Núcleo de Astrofísica Teórica, Universidade Cruzeiro do Sul, R.
Galvão Bueno 868, 01506-000 São Paulo, SP, Brazil
4 - Institute of Astro- and Particle Physics, Technikerstrasse 25/8,
6020 Innsbruck, Austria
5 - Max-Planck-Institut für extraterrestrische Physik,
Giessenbachstraße, 85748 Garching be München, Germany
Received 7 September 2009 / Accepted 21 June 2010
Abstract
Aims. We trace the interaction processes of galaxies
at intermediate redshift by measuring the irregularity of their ionized
gas kinematics, and investigate these irregularities as a function of
the environment (cluster versus field) and of morphological type
(spiral versus irregular).
Methods. We obtain the gas velocity fields by
placing three parallel and adjacent VLT/FORS2 slits on each galaxy.
To quantify irregularities in the gas kinematics, we use three
indicators: the standard deviation of the kinematic position
angle (
), the mean deviation of the
line of sight velocity profile from the cosine form which is measured
using high order Fourier terms (
k3,5/k1)
and the average misalignment between the kinematical and photometric
major axes (
). These indicators are then
examined together with some photometric and structural parameters
(measured from HST and FORS2 images in the optical) such as
the disk scale length, rest-frame colors, asymmetry, concentration,
Gini coefficient and M20.
Our sample consists of 92 distant galaxies.
16 cluster (
and
)
and 29 field galaxies (
,
mean z=0.44) of these have velocity fields with
sufficient signal to be analyzed. To compare our sample with
the local universe, we also analyze a sample from the
SINGS survey.
Results. We find that the fraction of galaxies that
have irregular gas kinematics is remarkably similar in galaxy clusters
and in the field at intermediate redshifts (according to
,
,
).
The distribution of the field and cluster galaxies in (ir)regularity
parameters space is also similar. On the other hand galaxies
with small central concentration of light, that we see in the field
sample, are absent in the cluster sample. We find that field galaxies
at intermediate redshifts have more irregular velocity fields as well
as more clumpy and less centrally concentrated light distributions than
their local counterparts. Comparison with a SINS sample of
11
galaxies
shows that these distant galaxies have more irregular gas kinematics
than our intermediate redshift cluster and field sample. We do not find
a dependence of the irregularities in gas kinematics on morphological
type. We find that two different indicators of star formation correlate
with irregularity in the gas kinematics.
Conclusions. More irregular gas kinematics, also
more clumpy and less centrally concentrated light distributions of
spiral field galaxies at intermediate redshifts in comparison to their
local counterparts indicate that these galaxies are probably still in
the process of building their disks via mechanisms such as accretion
and mergers. On the other hand, they have less irregular gas kinematics
compared to galaxies at .
Key words: galaxies: evolution - galaxies: kinematics and dynamics - galaxies: clusters: general - galaxies: spiral
1 Introduction
Galaxy clusters are important laboratories for understanding the origin
of different morphological types of galaxies. The main reason for that
is the relation between local galaxy density and morphological type (Dressler 1980).
For nearby rich clusters, the spiral galaxy fraction decreases
from
in the field to
in the cluster outskirts and to virtually zero in the core region. This
relation is redshift dependent and while the fraction of elliptical
galaxies (
,
Vogt et al. 2004)
does not change with redshift, the S0 fraction
increases with decreasing redshift and the spiral fraction, on the
contrary, decreases (Couch
et al. 1998). The fraction of spirals with no
current star formation activity is significantly larger in clusters
than in the field (van
den Bergh 1976; Goto et al. 2003; Sikkema 2009;
Poggianti
et al. 1999; Couch et al. 2001; Verdugo
et al. 2008). Also, distant clusters have a larger
fraction of star forming galaxies compared to nearby clusters (Kodama &
Bower 2001; Butcher
& Oemler 1984,1978; Ellingson et al. 2001).
It is well established with these observational studies that
spiral galaxies have been transformed into S0s mostly in denser regions
of the universe. Then the question is what are the physical processes
that are responsible for this morphological transformation. Several
mechanisms have been proposed such as gas stripping mechanisms: ram
pressure stripping (Kapferer
et al. 2009; Gunn & Gott 1972; Kapferer
et al. 2008; Quilis et al. 2000; Kronberger
et al. 2008), viscous stripping (Nulsen
1982) and thermal evaporation (Cowie
& Songaila 1977); tidal forces due to the cumulative
effect of many weak encounters: harassment (Moore et al. 1998; Richstone 1976);
removal of the outer gaseous halos by the hydrodynamic interaction with
the intracluster medium (ICM) plus the global tidal field of the
cluster: starvation (Larson
et al. 1980); mergers and strong galaxy-galaxy
interactions which are efficient when relative
velocities are low, and therefore, they mostly occur in galaxy groups
or in the outskirts of clusters (Makino
& Hut 1997). It is known that cluster
galaxies loose gas because of their interactions with the ICM and as a
result, their star formation gets switched off. Local studies show that
cluster galaxies are deficient in neutral hydrogen compared to their
field counterparts and that becomes significant within the Abell radius
(Gavazzi 1989;
Solanes
et al. 2001; Gavazzi 1987; Davies & Lewis 1973; Giovanelli &
Haynes 1985). The HI distribution of these galaxies
frequently shows asymmetries and displacement from the optical disk as
well
(Bravo-Alfaro
et al. 2000; Vogt et al. 2004; Gavazzi 1989;
Cayatte
et al. 1994). It was proposed that passive
spiral galaxies in clusters might be the intermediate phase before
becoming an S0 (van den Bergh 1976).
Later on, it was argued that S0's can not be formed
by removing gas from disks of spirals via mechanisms such as ram
pressure stripping, since S0's have systematically larger bulge sizes
and bulge to disk ratios (B/D) compared to spiral galaxies in
all density regimes (Burstein
1979; Gisler
1980; Dressler
1980; but see also Aragón-Salamanca
2008). Tidal interactions (e.g. harassment) on the other hand
are expected to trigger gas accretion into the circumnuclear regions (Moore et al. 1996) and
therefore increase the bulge size and B/D ratio. Therefore,
S0's might have formed via minor mergers, harassment or a
combination of the two (Hinz
et al. 2003; Dressler & Sandage 1983; Neistein
et al. 1999; Aguerri et al. 2001).
All these discussions are pointing out that studying stellar
populations and morphologies of cluster galaxies is crucial in
understanding the interaction processes. What about their kinematics?
In the Virgo cluster, for example, half of
89 spiral galaxies that were observed by Rubin
et al. (1999) turned out to have disturbed gas
kinematics. Mergers and tidal processes such as harassment are capable
of causing disturbances also in stellar velocity fields (Moore
et al. 1999; Mihos 2004). ICM-related processes on
the other hand, even ram-pressure stripping are insufficient to be able
to affect stellar kinematics of spiral galaxies (Quilis
et al. 2000). Some attempts have been made to
evaluate the effectiveness of the interaction processes as a function
of location in the galaxy cluster. Dale
et al. (2001) measured Tully-Fisher Relation (TFR)
residuals for 510 cluster spirals and concluded that they do
not show a dependence on distance from the cluster center. Moran et al. (2007b)
constructed the TFR in both
and V bands for 40 cluster,
37 field spirals at intermediate redshift and found that the
cluster TFR exhibits significantly larger scatter than the
field relation in both bands and the residuals do not show a clear
trend with
.
They found that the TFR residuals do not correlate with the
star formation rate and dust content. They also checked whether central
surface mass density of galaxies, which can be used to probe the action
of harassment, shows a trend as a function of radius. They found that
it shows a break at approximately
,
outside of which spirals exhibit nearly uniformly low central density
values. They argue that a combination of merging in the cluster
outskirts with harassment in the intermediate and inner cluster regions
might explain both the TFR scatter and the radial trend in
density which persist up to
.
Table 1: Basic galaxy cluster information.
As discussed above, galaxy evolution in clusters is rather complex, since there are several interaction mechanisms involved. To understand the nature of these mechanisms, it is important to examine together morphological and kinematical properties of cluster galaxies. In this series of papers we make use of both gas velocity fields and high resolution images of galaxies in four intermediate-redshift clusters and their field to do that. Most studies in the literature rely on long-slit data for identifying kinematical disturbances. Using a velocity map enables us to have a more accurate measure of the kinematical (ir)regularity. A velocity field can be decomposed into velocity, position angle and inclination of circular orbits at each radius (see Krajnovic et al. 2006). The deviation of the kinematic major axis (KMA) around its mean value and the misalignment between KMA and the photometric major axes (PMA) both indicate kinematical disturbance. We also make a simple rotating model that has the mean position angle and inclination of the observed velocity map. The residual of the observed and the simple rotating map is fitted with high order Fourier terms and the squared sum of these terms is used as another indicator. We measure these irregularity indicators for both field galaxies and cluster members and compare them with each other to search for the environmental imprint on gas kinematics. We then combine this information with the morphological and photometric properties of these galaxies and investigate whether certain characteristics make galaxies more sensitive to environmental effects. We also use the relations between intrinsic galaxy properties and efficiency of interaction processes, that are known from theory, to investigate which mechanisms are at work on the cluster galaxies in our sample.
We also investigate the evolution of field galaxies by
studying their gas kinematics as a function of redshift. We measure the
irregularities in their gas kinematics both at intermediate redshifts
and in the local universe and compare them with each other. These
results are then compared with the studies of spatially resolved gas
kinematics at similar or higher redshifts: Shapiro
et al. (2008, hereafter S08) analyzed gas velocity
fields and velocity dispersion maps of 11 galaxies at ,
observed with SINFONI, and classified these systems into two
categories: merging and non-merging. They found that more than
of these galaxies are consistent with a single rotating disk
interpretation. With FLAMES at the VLT, Yang
et al. (2008, hereafter Y08) studied
63 intermediate-mass field galaxies at
0.4<z<0.75. Using spatially resolved
gas kinematics of these objects (
field
of view) they find that both velocity fields and velocity dispersion
maps of
of these galaxies are incompatible with disk rotation.
Spatially resolved velocity fields are essential for
quantifying irregularities in the kinematics. Because the inclination
and the position angle of the orbits at each radii can be assessed and
the velocity profile along each orbit can be analyzed and compared with
a simple rotating case. For Tully-Fisher studies the main
problem with the long slit data is the fact that it can be misleading
in case the kinematic and photometric axes are misaligned. The
conventional way of obtaining the spatially resolved spectra is using
integral field (IFU) spectroscopy (e.g. S08, Y08, Puech
et al. 2008). We use another approach and place
three parallel, adjacent VLT/FORS2 slits on each galaxy. This novel
method has the advantage that we can explore the velocity fields up to
large radii (
,
which corresponds to 16 kpc at z = 0.4)
and it is more efficient than IFUs in terms of observing time. The
spatial sampling along the minor and major axes is
and
respectively. We described our method and presented the analysis of our
MS 0451 sample in Kutdemir
et al. (2008, hereafter Paper III). Here,
we include in our analysis galaxies in three more intermediate redshift
clusters and their field. A plan of the paper follows.
In Sect. 2,
we describe our sample and the improvements in our data reduction
technique in comparison with Paper III.
In Sect. 3,
we explain the analysis of the data. In Sect. 4, we discuss our
results and compare them with the literature. Section 5 summarizes the
results and our conclusions.
Throughout this paper, we assume that the Hubble constant, the
matter density and the cosmological constant are H0
= 70 km s-1 Mpc-1,
and
respectively (Tonry et al. 2003).
2 Sample and data properties
2.1 Sample
Our sample includes four galaxy clusters which have different properties (Table 1). To be able to compare the galaxies that experience similar environmental conditions, we scale cluster-centric distance by each cluster's virial radius. It is known that even galaxy clusters at the same redshift can be very different from one another. Two well-studied rich clusters in the local universe, Coma and Virgo are a good example for that. While Coma is dynamically relaxed and spiral poor, Virgo on the contrary is unrelaxed and spiral rich (Poggianti 2006).
Here we give some information about each cluster in our
sample: MS 0451 is a massive cluster with very high X-ray
luminosity.
of its spiral population are passive (Moran
et al. 2007a); MS 1008 is a very regular
and rich cluster (Luppino
et al. 1999; Lewis et al. 1999);
MS 2137 is a rich and dynamically relaxed cluster (Jeltema et al. 2005);
Cl 0412 (F1557.19TC) is a poor cluster that is not
well-studied. Our cluster selection depended on the availability of
their HST/WFPC2 imaging when the project was initiated in 1999. See Ziegler et al. (2003, hereafter Paper I)
and Jäger et al. (2004, hereafter Paper II)
for more detailed information about the sample selection.
![]() |
Figure 1:
Distribution of H |
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During the target selection, we gave priority to galaxies from our
previous studies, both in field and cluster environments, that have
detectable emission lines for extracting velocities. Further objects
were drawn from a catalog provided by the CNOC survey (Ellingson et al. 1998)
with either redshift information or measured (g-r) color
that matches expectations for spiral templates at
.
If there was an unused slitlet in the MXU setup, and no
suitable candidate was available, a galaxy was picked at
random. For our analysis, we also use a sample from SINGS as a
local reference for comparison (see Paper III).
SINGS galaxies are a diverse set of local normal galaxies (Kennicutt et al. 2003).
Daigle et al. (2006)'s
subsample that we use in our analysis consists of galaxies that have
star forming regions, so that their H
kinematics could be
extracted. We excluded from our analysis the galaxies in this sample
that have luminosities that are very different from the luminosities of
our intermediate redshift sample, so that the two samples have
comparable stellar masses. In Fig. 1, we compare the H
luminosities
of galaxies in our sample and in the local sample. H
luminosities
of the galaxies in our sample were calculated using the available
emission lines in their spectra as explained in Sect. 3.3. Since the galaxies
in our sample were selected mainly based on the strength of their
emission, several of them have larger H
luminosities, and
therefore, higher star formation rates than the galaxies of the local
sample. This raises the question whether our sample is biased towards
disturbed galaxies, since perturbations are expected to trigger star
formation and consequently increase the strength of emission lines. The
Kolmogorov-Smirnov (K-S) test of these distributions does not
indicate a significant difference between the H
luminosities of the
two samples (Table 2).
However, we check our results by repeating the analysis for a subsample
that is in the same H
luminosity
interval as the local sample.
We presented the analysis of our MS 0451 sample in
Paper III. We give the basic information about the rest of the
sample in Table 3.
The first character of a galaxy name indicates the sample
(1: MS 0451; 2: MS 1008;
3: MS 2137; 4: Cl 0412). The second
character is ``C'' for cluster members and ``F'' for
field galaxies. The last part of the name assigns a number to each
galaxy. We identified galaxies with redshifts between
below and above the cluster redshifts as cluster members. Only for
MS 0451, which was analyzed in Paper III, we used the
redshift interval defined by Moran
et al. (2007b) using the redshift distribution of
over 500 objects. That gives an
interval which is
larger on both sides than what the
definition gives.
For Cl 0412, Dressler
et al. (1999) determined cluster membership using
the redshift distribution of 22 galaxies. The redshift
interval they define selects the same galaxies as the
criterion
to be cluster members.
Table 2:
K-S statistics of H
luminosities of our sample and the local sample.
Table 3: Basic galaxy information.
In Sect. B in the Appendix, we give some information about each galaxy. In case the galaxy has emission lines, we present:
- a-
- the HST-ACS image of the galaxy in the F606W (broad V band filter);
- b-
- rotation curves of different emission lines extracted along the central slit without correction for inclination and seeing;
- c-
- position angles of kinematic and photometric axes as a function of radius;
- d-
- rotation curves extracted along the central slit and the kinematic major axis;
- e-
- velocity field obtained using the strongest line in the spectrum;
- f-
- normalized flux map of the line used for constructing the velocity field;
- g-
- velocity map reconstructed using 6 harmonic terms;
- h-
- residual of the velocity map and the reconstructed map;
- i-
- simple rotation map constructed for position angle and ellipticity fixed to their global values;
- j-
- residual of the velocity map and the simple rotation model;
- k-
- position angle and flattening as a function of radius;
- l-
- k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius.
2.2 Spectroscopic data
Our observations were spread across 5 nights in October and
November 2004 for Cl 0412 (seeing
(FWHM));
7 nights in December 2004
and February 2005 for MS 1008 (seeing
);
5 nights between May and July 2005 for
MS 2137 (seeing
).
Each sample was observed using three masks and the integration time of
each mask was split into three exposures. Even in cases where all three
exposures were taken during the same night, the frames were
not perfectly aligned, therefore, we completed the reduction of each
frame before combining them.
The spectral data reduction was done in the same way as
explained in Paper III, apart from using a different sky
subtraction method, which improved the results considerably.
In Paper III, the sky is modelled in spectra
that are interpolated along the X axis for
wavelength calibration. Here we use the algorithm described in Kelson (2003) which is based on
modelling the sky in the original data frame as a function of the
rectified coordinates. Modelling the sky before applying any
rectification/rebinning to the data reduces the amount of noise that is
introduced to the
data during the sky-subtraction process (see also Milvang-Jensen
et al. 2008). To quantify the difference,
we reduced one of our spectra using both the old and the new methods.
We averaged 15 spatial rows, that are far from the galaxy
spectrum, and therefore include sky-line residuals only.
A third order polynomial was fitted to and then subtracted
from this distribution across the wavelength axis and the root mean
square of the counts was calculated for both spectra.
A comparison of the two shows that the noise is
less in case we use the new sky subtraction method.
To be able to compare the H
emission line fluxes of our sample with the local sample, we applied a
rough flux calibration to our data. We used the spectrum of a star that
we observed together with our MS 0451 sample for the
calibration of all our data, since they were observed
with the same instrument. The star that we used is
in
the PMM USNO-A2.0 catalogue of Monet
et al. (1998). We transformed the B
and R magnitudes of the star given in the
catalog onto the standard Johnson-Cousins system using the conversions
provided by Kidger (2003).
2.3 Photometric data
Environmental effects on how a galaxy evolves depend on its intrinsic
properties. For example it is known that harassment is more
efficient on low central surface mass density galaxies (Moore et al. 1999).
In this context, it is important to test whether the
abnormalities that we see in gas
kinematics of a galaxy correlate with its photometrical properties.
To investigate this issue, we use both VLT/FORS2 and
HST/ACS images. We obtained imaging of the MS 1008,
MS 2137 and Cl 0412 samples in the ACS/ filter
while we exploited existing imaging of MS 0451 in the
ACS/
filter
from the ST-ECF HST archive. Ground based images were taken in
the B, V, R
and I filters for the whole sample. The
FORS2 filters B, V
and I are close approximations to the
Johnson-Cousins (Bessell
1990) photometric system while the R filter
is a special filter for FORS2 that is similar to the Cousins R
.
3 Analysis
3.1 Photometry
Surface photometry analysis, magnitude measurements, extinction and k-correction were done in the same manner as explained in Paper III. We have not applied an internal dust (inclination) correction. Galactic extinction and k-corrected MB magnitudes, rest-frame B-V, V-R and R-I colors of the galaxies in our sample are given in Table C.1 in the Appendix. k-correction was done using the k-correct algorithm by Blanton & Roweis (2007).
Abraham et al. (1994)
defined concentration and asymmetry parameters to be able to do the
morphological classification of galaxies in a quantitative and
automated way. The first parameter quantifies how concentrated the
light distribution of an object is, and it is larger for
earlier type galaxies. The second parameter measures how asymmetric the
light distribution of a galaxy is and becomes larger for later type
galaxies. We use slightly different definitions for asymmetry and
concentration parameters than in Paper III. Here we give the
new definitions that are based on Abraham
et al. (1996) and Conselice
et al. (2000). The concentration is the ratio of the
flux within G1, the
area inside the isophote
of the sky level and G2,
the region which has the same axis-ratio as G1,
but has a major-axis size that is 0.3 times the major-axis
size of G1:
The asymmetry parameter A is the normalized residual of a galaxy image and its 180 degrees rotated counterpart. It is calculated within the


We measure two additional parameters that we did not use in Paper III: the Gini coefficient and the M20 index (Abraham et al. 2003; Lotz et al. 2004). The Gini coefficient quantifies the non-uniformity in the light distribution and strongly correlates with the concentration index for local galaxies. Since the Gini coefficient has no dependence on the definition of the center of an object (Eq. (3)), it is often used as an alternative to the concentration parameter in studies of high-redshift galaxies, a large fraction of which are peculiar.
where |fi| are the absolute flux values of a galaxy's constitutent pixels sorted in increasing order,

Table 4: Eye-ball morphological classification of the MS 0451 sample.
![]() |
Figure 2: Distribution of morphological parameters for our sample and the local sample. a) Concentration parameter. b) Asymmetry parameter. c) Gini coefficient. d) M20 index. |
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The M20 index is based on
the total second-order moment
,
which is the flux in each pixel fi
multiplied by its squared distance to the galaxy center, summed over
all pixels of the galaxy (Eq. (4)).





M20 correlates with the square of the distance of the brightest regions of a galaxy from its center, which makes it sensitive to merger signatures. M20 is smaller for centrally concentrated objects (early types) and increases in case of off-center light concentrations, spiral arms, bright nuclei, bars, etc.
We present the asymmetry, concentration, Gini and M20 parameters of our galaxies in Table C.1 in the Appendix. The same parameters for the SINGS galaxies are given in Table 5. We applied a K-S test to the asymmetry, concentration, Gini and M20 distributions of the local versus distant field samples as well as the distant cluster versus field samples. Only the galaxies for which we have spectroscopic redshifts (see Table 3 here and Table 1 in Paper III) and that were classified as late types (spiral or irregular) according to our eye-ball classification (Tables 3 and 4) were used in this analysis. Galaxy 2F19 was also excluded since it is not distant (z=0.0052). The results are given in Table 6 and the distributions are shown in Fig. 2. The distant cluster and field samples have significantly different distributions for the concentration, Gini and M20 parameters. For the asymmetry, the difference between the two samples is considerable, but not very significant. The distributions of the local and distant field samples are significantly different for the M20 and concentration parameters. The difference is large for the Gini coefficient while the significance level of the statistic is not very high. The asymmetry distributions are similar for the two samples.
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Figure 3: Distribution of galaxies in our sample and a local sample from SINGS on the A-C plane. Their morphological types, that are determined by our eye-ball classification (Table 3, Col. 7), are indicated with different symbols as shown in the legend. The dash-dotted green lines are the selection limits separating different morphological types determined by Menanteau et al. (2006). The borders that are adjusted by minimizing the amount of contamination from different types in each region are shown with black dotted lines. |
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The rest-frame wavelength of the ACS images of our sample corresponds to the B band, therefore we used blue KPNO, CTIO, Palomar and Isaac Newton images of the SINGS galaxies for the measurements. These images were convolved with a point spread function and then rebinned to have the same seeing and pixel size in kpc as the HST images of our sample at the mean redshift of our clusters (z=0.4). The asymmetry and concentration parameters can be used for morphological classification. We present our galaxies and local galaxies from SINGS on the A-C plane together with our eye-ball classification of their morphologies in Fig. 3. Selection limits which separate different morphological types on the plane, as determined by Menanteau et al. (2006), are shown on top of this plot. The borders are then adjusted by minimizing the amount of contamination from different types in each region.
Table 5: Photometric parameters for the SINGS sample.
Table 6: K-S statistics of the morphological parameters of our sample and the local sample.
3.2 Kinematics
We analyze the gas kinematics of our whole sample in the way that was described in Paper III, using a sample from SINGS as a local reference for comparison (see Paper III). As stated in the introduction section, we look for indications of disturbance in velocity fields to be able to examine environmental effects. There are three parameters that we use for quantifying these abnormalities:
- a-
- the standard deviation of the kinematic position
angle (
);
- b-
- the average misalignment between the photometric and
kinematic axes (
);
- c-
- the mean deviation of the velocity field from a simple rotating disk ( k3,5/k1).
Table 7: Parameters quantifying the (ir)regularity of the gas kinematics measured for our sample.
3.3 Star formation rates
Here we analyze the star formation properties of the galaxies in our
sample. We use the total fluxes of available emission lines in the
spectra to measure the star formation rates (SFR). The luminosities are
calculated using these fluxes and corrected for extinction following Tully & Fouqué (1985). The
inclinations are measured from our HST/ACS imaging (Table C.2). For a
comparison between different extinction corrections, we have applied
the definitions of Giovanelli
et al. (1994) and Tully
et al. (1998), which makes a factor of difference
at most in SFRs. Tully & Fouqué
(1985) better matches the extinction law (Cardelli
et al. 1989) for reasonable values of E(B-V).
Star formation rates that rely on [OII]3727 or H
line were calculated
applying Kennicutt (1992) and
for H
,
case B recombination was assumed, which implies a
factor 2.86 difference in comparison with H
.
Note that we have not corrected the
luminosities
for underlying stellar absorption. For the calculations based
on [OIII]5007 we have followed Maschietto
et al. (2008) and Teplitz
et al. (2000).
![]() |
Figure 4:
SFR versus stellar mass for our sample and the local sample from SINGS.
The SFR-stellar mass relation based on |
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![]() |
Figure 5: Specific star formation rate versus rest-frame B-V color for our sample and the local sample from SINGS. |
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In Fig. 4,
we plot the SFR versus stellar mass for the galaxies in our sample.
A comparison with the relations for
and
galaxies
and the SINGS local sample shows that SF properties of the
galaxies in our sample cover a wide range and some galaxies have higher
star formation rates than the
relation.
It should be noted that this relation has a large intrinsic
scatter at all redshifts. In Fig. 5 we show
specific SFR versus rest-frame B-V
which follows the expected trend.
Since we calculated the star formation rates using the
integrated flux from three adjacent slits that cover a galaxy, aperture
effects are negligible. On the other hand, we are forced to use
different emission lines for calculating SFRs due to the different
rest-frame wavelength coverage of the spectra from galaxies at
different redshifts. The conversions that are used for this purpose are
likely to cause some systematic errors (Moustakas
et al. 2006). To check for our sample, how
successful it would be to use a constant factor for conversion from one
emission line flux to the other, we plot the frequency distribution of
emission line flux ratios in Fig. 6. This exercise
shows that the uncertainty in H luminosities
(Table 8)
that is caused by these differences (sigma of the distribution) is
about a factor 2.
Table 8:
H
luminosities.
![]() |
Figure 6: Histograms of the emission line flux ratios. |
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Figure 7:
Histograms of the mean misalignment between kinematic and photometric
major axes (
|
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Table 9: K-S statistics of (ir)regularity parameters of the cluster and field galaxies in our sample.
Table 10: K-S statistics comparing the kinematic (ir)regularity parameters of the galaxies in our sample classified as spiral or irregular/ peculiar using their photometry.
![]() |
Figure 8:
Histograms of the mean misalignment between the kinematic and
photometric major axes (
|
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3.4 Frequency distribution of the kinematic irregularities
In Figs. 7d-f,
we show the frequency distribution of each (ir)regularity parameter for
the field and cluster galaxies in our sample. The same information for
local galaxies
is given above each plot for comparison (Figs. 7a-c). Cluster and
field galaxies are distributed in a similar manner in the
(ir)regularity parameters space. Both cluster and field galaxies
populate regions inside and outside the area where regular velocity
fields of local galaxies are located. The Kolmogorov-Smirnov
(K-S) test of the distributions also confirms that field and
cluster populations are not significantly different from one another
(see Table 9).
Here we discuss the origin of the largest parameter values: the two
galaxies that have the largest
values
are 1F6 and 4F7. 1F6 has a kinematically decoupled core,
therefore, it is probably a merger remnant
(Paper III, Fig. B.13). 4F7 seems to be a
merger
too. The residual of its velocity field and reconstructed velocity map
reveals the existence of a counter-rotating component in the outer part
(see Figs. B.49g
and j). There are
tidal structures visible on its HST image as well
(Fig. B.49a).
The largest
belongs to 3F7 which has a
strong bar (Fig. B.40).
Although the
kinematic and the
photometric position angles match quite well in the disk region,
the extent of the observed velocity field does not go far
outside the bar (see Figs. B.40a,c,e),
therefore, this galaxy has a very large
value.
clearly has an
important contribution of a bar in case of two other galaxies in our
sample: 1F6 and 2C3. So a large
either
indicates a misalignment between the stellar disk and the
kinematic axis of the gas, or the presence of a bar.
In Sect. 3.1, we determined the morphological type of the galaxies by our eye-ball classification (Tables 3 and 4). Here we check how the (ir)regularity parameter values of different morphological types are distributed (Fig. 8) and find that irregularities in gas kinematics of spiral and irregular/peculiar galaxies are very similar (see Table 10 for the K-S test results).
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Figure 9:
(Ir)regularity parameters versus
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3.5 Dependence on the clustercentric distance
All cluster members in our sample, except for 4C2, are well inside the
virial radius, where both tidal processes and ICM-related mechanisms
are effective. In Fig. 9, we show the
distance of each galaxy from the cluster center in projection
(in virial radii) and plot that against (ir)regularity
parameters. There are quite a few galaxies within half a virial radius
from the center, that are below the irregularity threshold of
k3,5/k1
and .
69
of the cluster galaxies are regular according to both of these
parameters while most of them have large
values.
The fraction of galaxies within 1
that have regular gas
kinematics according to all the three criteria is 13
.
3.6 Correlations
Here we measure the correlations of the irregularity parameters with
the H luminosity,
with each other and with some photometric parameters using an outlier
resistant linear regression fitting technique (Table 11).
3.6.1
Correlations with H
luminosity
luminosities are listed in
Table 8.
In case the
line
was outside the observed wavelength interval, we converted the fluxes
of
available emission lines to
flux
as explained in Sect. 3.3.
For the cluster members, we find significant correlations
between the
and two indicators of kinematical irregularities:
and
k3,5/k1
(Figs. 10a
and b). H
emission
mainly stems from HII regions and it indicates star formation
(e.g. Kennicutt et al. 1994).
B-V color and H
luminosity
are expected to anti-correlate with each other for a given
morphological type since galaxies with bluer B-V colors
have a larger ratio of blue to red stars, and therefore, a better
capability of ionizing the gas to form HII regions (Cohen 1976). However, dust
extinction can weaken this correlation. For our data, we find a weak
anti-correlation between these two quantities only for cluster members
(Fig. 10c).
The irregularity parameters become larger for bluer galaxies. However
the trends are very weak (see Table 11).
3.6.2 Correlations between (Ir)regularity parameters
To be able to use the (ir)regularity parameters as a tool to
distinguish disturbed velocity fields from regular ones, it is
necessary to determine a threshold value for each of them. We did that
by measuring each parameter for local, regular velocity fields from
SINGS (see Paper III, Sect. 4).
In Fig. A.1
in the Appendix, we show how the galaxies in our sample and in the
local sample are distributed in the plane of one parameter versus
another. Regularity borders that are defined using the local galaxies
are indicated on each plot. We find a weak correlation between
k3,5/k1
and
(see Table 11)
which agrees with what we found in Paper III using only the
MS 0451 sample. If we look at the galaxies that have
large k3,5/k1
and
parameters, most of
them show signs of an additional kinematic component in the residual of
the simple rotating model and the original velocity field (residual
maps are presented in Sect. B,
part (j) of each figure). These galaxies are 1F4, 1F6, 4F7
and 4F8. In all cases, the existence of a secondary component
is clear in the residual map. k5 is
sensitive to extra kinematic components and
is
sensitive to their misalignment with the main component. Therefore,
the outliers of the
k3,5/k1 versus
plot mostly consist of velocity fields that have multiple kinematic
components. This explains the weak correlation between these two
parameters.
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Figure 10:
a) H |
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Table 11: Linear Pearson correlation coefficients.
Table 12: Irregularity fraction.
3.6.3 Correlations with photometric parameters
Apart from the Gini coefficient, M20, photometric asymmetry and concentration parameters that are defined in Sect. 3.1, the methods we use for measuring the morphological/ photometric parameters are explained in Paper III. Photometric and morphological parameters of the galaxies in our sample are given in Tables C.1 and C.2 respectively (see Paper III, Table C.2 for the morphological parameters of the MS 0451 sample.). The (ir)regularity parameters of the local sample galaxies are given in Paper III, Table 3. Their photometric parameters are given here, in Table 5.
To focus on the effects of the interactions that take place
only in clusters, we now restrict ourselves to our cluster sample,
where most galaxies are within half a virial radius from the cluster
center. In this region, mergers are rare, while harassment and
ICM related mechanisms such as ram pressure stripping are expected to
be effective (Moore et al.
1997). We give the correlation measurements of the cluster
members that are located within
from
the cluster center in Table 11.
The parameters
that correlate with each other are plotted in Fig. 11 and discussed
in Sect. 4.5.
3.7 The fraction of irregular gas kinematics
We quantified irregularities in gas kinematics using three different parameters, and for each of them, we compared the number distribution of field and cluster galaxies. Now we will look at the fraction of galaxies that have irregular gas kinematics. Fractions that are measured for each irregularity type separately and also without distinguishing between the three types are given in Table 12. We obtain very similar fractions of irregular gas kinematics for cluster and field environments. Each irregularity parameter gives a very different fraction compared to the others, which will be discussed in Sect. 4.3.
3.8 Special cases
Here we explain the cases that we exclude from our analysis. For the
same information on the MS 0451 sample, see
Paper III, Sect. 4.1. For face-on galaxies,
photometric position angle measurements are very uncertain. Since
LOS velocities are very small in such cases,
the effect of
noise becomes more pronounced in velocity fields. This causes
to be unreliable. Therefore,
we excluded such cases from our
analysis (2F4, 2F11, 2F12, 4C3). Among
those, 2F11 is an extreme case which is completely excluded
from the analysis (see Fig. B.29e). The other
galaxies that we did not use in our analysis are 2F5, 2F15&16.
2F5 does not have any signal in the
upper slit, which affects the measurements. Looking at the iso-velocity
lines on the receding side (Fig. B.23e),
it looks as if the highest positive velocities are located in
the top right corner, which is missing on the map. 2F15&16 (see
Fig. B.33)
are at the same redshift, however it is not clear what kind of objects
they are and the emission line they have could not be identified. The
velocity field includes information from both, but most of it comes
from 2F15. The [OIII]5007 velocity field of 4F4 (see
Fig. B.46e)
looks quite disturbed, although the flux map of the same emission line
looks rather regular. Emission from this galaxy is very strong and
therefore, we can rely on its (ir)regularity parameters.
4 Discussion
4.1 Frequency distribution of the kinematic irregularities
We analyze together gas kinematics and stellar photometry of spiral
galaxies in clusters and in the field. We find that the fraction of
galaxies that have irregular gas kinematics is very similar in our
cluster and field samples. These two samples also give a very similar
frequency distribution of each (ir)regularity parameter. When
interpreting the results we have to consider that our sample selection
is based on the emission line flux of galaxies. A comparison of our
sample with a local sample from SINGS shows that some galaxies in both
our cluster and field samples have higher H luminosities, and
therefore, higher star formation rates (Fig. 1). In some
of these cases, high star formation activity might be the result of
some type of interaction. It has to be considered, however,
that H
luminosity
of a galaxy can also increase due to facts that are unrelated to
interactions such as regular starbursts (Kennicutt
1998).
In Figs. 7g-i
we show how the subsample of galaxies that have H luminosities within
the same interval as the SINGS sample is distributed in the
(ir)regularity parameters space. The field galaxies that are populating
the high irregularity end of the plots are not necessarily
the ones with high H
luminosities.
So, independent from whether the high star formation galaxies
are included or not, the distribution of cluster and field
galaxies in irregularity space is very similar. The majority of the
field galaxies in our sample are more irregular than local field
galaxies according to at least one of the three (ir)regularity
criteria. This is the case even if we take into account only the ones
that have H
luminosities
within the
same interval as the SINGS sample, which are mostly in the
interval
.
This could be the result of a higher occurence of disk building
processes such as mergers and accretion events at these redshifts.
Using N-body simulations, Gottlöber
et al. (2001) investigate the relative major merger
rate of the population of cluster, group and isolated halos as a
function of redshift. They find that for cluster galaxies, the relative
merger rate increases with redshift while it decreases for isolated
galaxies. At
,
they find the major merger rate in the field to be two times as high as
that in clusters (see Gottlöber
et al. 2001, Fig. 9).
In the local universe, evidence has been accumulating, mainly from HI studies, on the importance of cold gas accretion: a large number of galaxies are accompanied by gas-rich dwarfs or are surrounded by HI cloud complexes, tails and filaments (Sancisi et al. 2008). Most of the high-velocity clouds around the Milky Way are now widely accepted to belong to its halo and direct evidence for infall of intergalactic gas (Wakker et al. 2007,2008). Recently, accretion of satellites has also been revealed by studies of the distribution and kinematics of stars in the halos of the Milky Way and of M 31. The discovery of the Sgr Dwarf galaxy (Ibata et al. 1994) is regarded as proof that accretion is still taking place. It is also possible that the warped outer layers, lopsidedness and the extra-planar gas, which are very common features in galaxies, are related to the accretion process. Observational results suggest cold gas accretion to be a likely formation mechanism for the polar disks (Bravo-Alfaro et al. 2004; Stanonik et al. 2009). Simulations support this picture (Macciò et al. 2006).
The radial velocity difference and angular separation of some
galaxies in our sample suggest that they may be gravitationally bound
to each other. Since we do not have the spectra of the objects
surrounding the galaxies in our sample, we can not make a definite
statement of whether they are group members or not. The number
statistics in Huchra & Geller
(1982) show that velocity dispersions up to 400
and sizes up to 2 Mpc
are likely (with median values of
155
and 0.7 Mpc) for
galaxy groups. For galaxy pairs, it
is expected that at least 35 percent of the ones with
projected separation of less than 20 h-1 kpc
and velocity difference of less
than 500
are physically bound (De Propris
et al. 2007). On the other hand there are several
interacting pairs with a projected separation of around 50 h-1 kpc
(Patton
et al. 2000; Barton et al. 1999). Lambas et al. (2003) find
that star formation in galaxy pairs is significantly enhanced over that
of isolated galaxies with similar redshifts in the field for projected
separations less than 25 h-1 kpc
and velocity differences of less than 100
.
Based on this information, the galaxies in our sample that
might be gravitationally interacting with each other are listed in
Table 13.
The average values of each irregularity
parameter for these galaxies (excluding the unreliable values that are
mentioned in Paper III for the MS 0451 sample and
here, in Sect. 3.8
for the rest) are k3,5/k1=0.15,
and
.
Among these galaxies, 4F7 has a very large
and 4F12 has a very
high
k3,5/k1.
Excluding the galaxies in Table 13
from the comparison between the irregularity distributions of the
cluster and field galaxies (see Sect. 3.4) does not change
the results (see Table 14).
Table 13: Possible dynamical pairs.
Table 14: K-S statistics of (ir)regularity parameters of the cluster and field galaxies in our sample, excluding possible dynamical pairs.
4.2 Frequency distribution of the morphological parameters
In Sect. 3.1 we compare the distributions of some morphological parameters: asymmetry, concentration, M20 and Gini coefficient for distant cluster versus field samples as well as for local versus distant field samples (see Fig. 2 and Table 6). We find a significant difference between the distribution of the concentration, the Gini coefficient and the M20 parameter for the cluster versus field galaxies at intermediate redshifts, in the sense that the cluster sample lacks galaxies with low concentration index. This might be due to the activity of interaction processes such as harassment which causes matter to migrate towards the center.
The local and distant field samples are also different: the concentration, the Gini coefficient and the M20 index all suggest that local galaxies have a more centrally-concentrated and less clumpy light distribution with respect to the distant galaxies. This is consistent with what we find studying gas kinematics: it looks as if field galaxies at intermediate redshifts are still in the process of building up their disks.
4.3 The fraction of irregular gas kinematics
In Y08, the [OII] doublet velocity fields of 63 field
galaxies, that are at z=0.4-0.75
and that have
,
are analyzed. They classify galaxy
kinematics based on an eye-inspection of the gas velocity map, gas
velocity dispersion map and high resolution image together. Their study
of velocity fields however is limited to
field
of view while it can be as large as
in
our case. They call a galaxy ``rotating disk'' if its velocity field
has an ordered gradient, the photometric and the kinematic
major axes are aligned and the velocity dispersion map has a single
peak close to the kinematic center. If the velocity dispersion
map has no peak or has a peak that is offset from the center while the
other criteria are satisfied, they classify the case as ``perturbed
rotation''. If both the velocity dispersion map and the
velocity map deviate from the
regular case, they classify it as ``complex kinematics''. Deviation
from the regular case for a velocity field corresponds here to an
irregular velocity gradient and/or a misalignment between
the photometric and kinematic axes. Therefore, when the three
indications we use are at the level of being detectable by eye within
the central part of a galaxy, its kinematics can be classified as
complex according to this scheme. Even then they find that
of their sample have velocity fields and velocity dispersion maps that
are both incompatible with disk rotation. When we calculate the
irregularity fractions of the field galaxies in our sample that are
within the same redshift interval as their sample, we find 10
(according to
), 60
(
), 30
(
k3,5/k1).
Their result is very close to what we find using the
k3,5/k1 criterion.
However it should be noted that most of the galaxies in our sample are
less massive (see Table C.1,
Col. 8).
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Figure 11:
(Ir)regularity parameters versus some photometric quantities. For each
plot, the line shows the correlation between the given parameters. The
local galaxies are not used in correlation measurements, but shown as a
reference in each plot. The names that are written in red and italic
belong to the galaxies that are excluded from the correlation as
explained in Paper III for the MS 0451 sample and
here, in Sect. 3.8
for the rest. a) M20 index
versus the mean misalignment between the photometric and kinematic
major axes (
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It is known from the local Universe that most galaxies in the central parts of galaxy clusters lack gas. To be able to study velocity fields of galaxies, priority was given to emission line galaxies in our sample selection. Therefore, most cluster galaxies in our sample are perhaps just infalling and have not been severely affected by the cluster environment yet. This would explain the similarity between the gas kinematics of cluster and field galaxies in our sample.
We use k3,5/k1,
and
to trace the effects of the interaction processes on gas kinematics. We
find that the irregularity fractions measured using each of
these parameters are very different from one another:
gives
a value around
,
k3,5/k1
and
for both cluster and field galaxies. This may have a number of
different reasons. One is the effect of lower spatial resolution for
intermediate redshift galaxies. Our simulations in Paper III,
Appendix A, indicate that small scale irregularities may be
smeared out as a result of the resolution effects.
A misalignment between the stellar disk and the rotation plane
of the gas on the other hand is unlikely to be affected much by low
resolution. One should also realize that not all galaxies with
high
are irregular.
For example, galaxies with bars can have larger
values.
Also, some galaxies in the local universe are found showing regular
kinematics with an HI polar disk (perpendicular to the stellar
disk) (van
Gorkom & Schiminovich 1997; Stanonik et al. 2009). Petrosian et al. (2002)
observed 18 blue compact dwarf galaxies and for 8 of
these they found strong misalignments between the photometric and
kinematic position angles although the isovelocity contours do not
indicate strong irregularities in gas motions. There are even merger
remnants in the local universe that have very regular gas velocity
fields such as NGC 3921 (Hibbard
& van Gorkom 1996).
4.4
Correlations with the H
luminosity
Larger irregularities (
k3,5/k1
and )
we find for higher
probably
show that galaxies which have more irregular gas kinematics
have higher star formation rates. These correlations are valid only for
cluster members (see Fig. 10). According to
models, most interaction processes in clusters increase star formation
activity at the
beginning, before they eventually suppress it. Gravitational
interactions are expected first to trigger nuclear gas infall. Models
by Fujita (1998) show that
increased star formation activity is expected in case of harassment,
since high-speed encounters between galaxies cause gas to accumulate to
centers of galaxies. Ram-pressure stripping, which is the hydrodynamic
interaction between the hot ICM and the cold ISM, leads to an increase
of the external pressure, shock formation, thermal instabilities and
turbulent motions within the disk. Evrard
(1991) and Bekki &
Couch (2003), for example, show that all these
events increase cloud-cloud collisions and cloud collapse, and
therefore, enhance star formation activity. However, in case
of ram-pressure stripping, there are not many observations supporting
this picture. Some examples in A1367 that experience ram-pressure
stripping are CGCG 97-023, where enhanced star formation
activity per unit mass, compared to galaxies of similar type and
luminosity is confirmed (Gavazzi
et al. 1995), CGCG 97-073 and
CGCG 97-079 (Boselli
& Gavazzi 2006). Models of Fujita
(1998) and Fujita &
Nagashima (1999) that quantify the variations of the star
formation activity, show that on short timescales (
yr) in
high-density, rich clusters, the star formation activity can
increase by up to a factor of 2 at most. But on longer
timescales, removal of the HI gas leads to a decrease of the fuel
feeding the star formation, and galaxies become quiescent (Fujita 1998;
Okamoto
& Nagashima 2001; Fujita & Nagashima 1999).
4.5 Correlations with photometric parameters
We find a weak correlation between M20
and
for cluster members
(Fig. 11a).
M20 becomes very
large in case the galaxy light has a clumpy distribution. Since
clumpiness is mainly caused by star forming regions, it means
that galaxies that have irregular gas kinematics have more star
formation. M20 also
increases towards later types. Since galaxies that have high mass
concentration (earlier types) are more resistant to tidal mechanisms,
the correlation we find is expected as a result of this fact
as well. The concentration parameter on the other hand, which
is another indicator of galaxy type, does not give any correlation with
the irregularity in gas kinematics. Therefore,
the substructures must be the main cause of the correlation
that we find.
We need to note that
can not be considered as a pure indicator of interactions since it is
sensitive to bars that are misaligned with the disk. Even though the
formation of a bar can be triggered by environmentally induced
gravitational instabilities, such as tidal interactions
between galaxies and the cluster potential well, it can also
just be the result of a misalignment between the disk and the triaxial
halo of the galaxy itself (Bekki
& Freeman 2002; Kodama & Smail 2001). Since a
bar is not necessarily formed by an interaction process, we remeasured
the correlation of
with the other parameters
excluding the cases where we see that a bar
has an important contribution to the
value
(3F7, 1F6 and 2C3). The results remained
the same.
We find a correlation between the disk scale length and
(Fig. 11b).
However, what we see on the plot is an increasing deviation
of
values with increasing
rather
than a correlation. While small galaxies are all regular, there are
both regular and irregular cases among larger galaxies. It is
known that some interaction processes are more effective on larger
galaxies such as interactions between galaxies and the cluster
potential well, viscous stripping and thermal evaporation. Tidal
interactions between galaxies, on the other hand, are more efficient on
smaller galaxies (Byrd & Valtonen
1990). What we see in our data might be an indication of the
activity of some of the first group processes in the central
of the clusters in
our sample.
We find that MB
and
anti-correlate with each other (Fig. 11c) showing that
more massive galaxies have more irregular gas kinematics. Since larger
galaxies are also more massive (Trujillo
et al. 2004), the interpretation of this correlation
is the same as the correlation that we find for the disk scale length.
One or a combination of the following mechanisms might be effective on
the cluster members in our sample: viscous stripping, thermal
evaporation and tidal interactions between galaxies and the cluster
potential well.
We investigated whether morphological peculiarities correlate with irregularities in the gas kinematics. Among the galaxies that have irregular/peculiar morphology according to our eye-ball classification (see Tables 3 and 4), there is no trend towards larger kinematical irregularities (see Fig. 8). We find very similar distributions of the irregularity parameters for spirals and irregular/peculiar galaxies (Table 10). We also do not find a correlation between the photometric asymmetry and irregularities in the gas kinematics. Neichel et al. (2008) on the other hand find a good agreement between their morphological and kinematical classifications.
For the correlations that we find for cluster galaxies, where
the parameter is
involved, it should be considered that there are only two
galaxies that are slightly above the irregularity threshold
of
(Figs. 11b
and c). Therefore, although we discuss the possibility of
these correlations being a result of cluster specific interaction
mechanisms, this is not a strong result.
4.6 Comparison with high redshift studies
S08 uses a method that is based on kinemetry to distinguish merging and
non-merging systems. They quantify the asymmetries in both the velocity
field and the velocity dispersion map of ionized gas. Using the
measurements of these two parameters for template galaxies, they
determine where merging and non-merging systems are located on the
plane of these parameters versus each other and define a criterion to
distinguish them from one another:
.
We measured the
parameter
of our velocity fields (Table 7)
and compared these with the
of the merging and non-merging
galaxies and models in S08
(see Fig. 12).
The quality of our sigma-maps is not satisfactory for an analysis.
However, the possibility that
and
give contradictory results is
very low (see Fig. 5
in S08). Therefore, we use
alone with the purpose of
making a comparison between the methods.
To measure a global ellipticity and a global inclination,
which are used while measuring the
parameter,
we calculate the median of their values outside half the full width at
half maximum of the seeing.
![]() |
Figure 12:
Number distribution of the |
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Figure 13:
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If we look at the
distribution of our galaxies, we see that most of them are located in
the region of the non-merging galaxies, as defined
by S08 (Figs. 12a,b).
is
similar to
k3,5/k1
and a comparison between these parameters for our galaxies shows that
they correlate with each other (Fig. 13,
correlation coefficient = 0.86). On the
other hand, the classification thresholds are quite different for
the two criteria. Following S08, most of our objects would be regular
while many more galaxies are classified as irregular with our method.
This is visible in Fig. 12 where the
distribution
of our galaxies is given together with non-mergers and mergers
in S08. Classification of these galaxies according to the
k3,5/k1 criterion
is indicated on the same plot. While the method of S08 aims at
separating mergers from non-mergers, it would not fulfill our
requirement of tracing the imprints of environmental processes.
4F7 (in the non-merger region with
= 0.17) is
a good example to explain that since the deviation of the position
angle, the residual map of the velocity field and the simple rotating
disk model and also the galaxy image itself provide signs of
a merger.
We find that the
galaxies in S08 are more irregular than our complete sample that
includes both cluster and field galaxies in
(see
Figs. 12b
and c). The K-S test results show that the maximum
deviation between these two distributions is
and the probability that the samples are similar is 0.002.
5 Summary and conclusions
Using gas velocity fields, we trace the activity of interaction
processes both in galaxy clusters and in the field. To measure
the irregularities in velocity fields, we use three different
indicators: the standard deviation of the kinematic position
angle (
), the mean deviation
of the LOS velocity profile from a cosine function which is
measured using high order Fourier terms (
k3,5/k1)
and the average misalignment between the kinematical and photometric
major axes (
). A regularity
threshold for each of these parameters is defined using local field
galaxies from SINGS. 16 cluster members (
and
)
and 29 field galaxies (at
)
are then analyzed and studied with respect to the local galaxies in the
field and compared with each other to evaluate the effect of
interaction processes on gas kinematics.
Our analysis shows that distant field galaxies have more irregular gas kinematics than their local counterparts. This suggests a higher frequency of disk-building processes such as accretion events and mergers in the distant universe. Morphological properties of these galaxies lead us to the same conclusion. The concentration, the Gini coefficient and the M20 index measurements indicate that distant field galaxies are more clumpy and less centrally concentrated than local field galaxies.
We make a comparison between gas kinematics of our
intermediate redshift sample and the sample of S08 using
the
parameter, which is
defined in S08 to distinguish merging and non merging systems.
We find that our sample, that includes both field and cluster galaxies
within
,
have more regular gas kinematics than the
galaxies.
Y08 shows that a large fraction of spiral galaxies with
at
z=0.4-0.75
have irregular gas kinematics. When they exclude these galaxies with
irregular kinematics, they find no evolution in the scatter and the
slope of the K-band TFR (Puech
et al. 2008). Our analysis shows that a large
fraction of less massive distant spirals at a median redshift of z=0.36
also have irregular gas kinematics.
We find that cluster and field galaxies are distributed in a similar manner in the (ir)regularity parameters space. We also measure the fraction of irregular velocity fields. For each parameter, we find remarkably similar fractions for cluster members and field galaxies. This shows that the cluster galaxies in our sample are not severely affected by the cluster environment. Galaxies in the central parts of clusters are expected to have an imporant fraction of their gas stripped via interaction processes and it is difficult to obtain velocity fields of these galaxies, especially at high redshifts. Therefore, it is probable that some cluster galaxies in our sample, for which the velocity fields could be analyzed, are just infalling. If this is the case, that explains the similarity we find between the gas kinematics of cluster and field galaxies. On the other hand, a comparison between the morphological properties of the cluster and field galaxies in our sample reveals a clear difference between them: the cluster sample lacks galaxies with low concentration index. This might be due to the activity of interaction processes such as harassment which causes matter to migrate towards the center. We compare the gas kinematics of spiral and irregular galaxies as well and find no significant difference between these morphological classes.
We find that galaxies with higher H
luminosities have larger
k3,5/k1
and
values.
In addition to that, galaxies with more substructures have
larger average misalignment between their kinematic and photometric
axes (
). Since substructures mostly
are star forming regions, all these correlations mean that galaxies
which have more irregular gas kinematics have high star formation
rates. This is consistent with the theory since most interaction
mechanisms in clusters increase star formation activity at the
beginning, before they eventually supress it.
We would like to thank Daniel Kelson for making his sky subtraction algorithm public, and Scott Trager for his help in using it. We thank Davor Krajnovic for the Kinemetry software. We are grateful to the authors of Daigle et al. (2006) for kindly providing us with the Hvelocity fields of the galaxies in the SINGS local sample. We thank Jacqueline van Gorkom for fruitful discussions. We thank the referee for the valuable comments. We appreciate the efficient support of ESO and the Paranal staff. This work has been financially supported by the Volkswagen Foundation (I/76 520), the Deutsche Forschungsgemeinschaft, DFG (project number ZI 663/6) within the Priority Program 1177, the Kapteyn Astronomical Institute of the University of Groningen and the German Space Agency DLR (project number 50 OR 0602). E.K. thanks the Netherlands organization for international cooperation in higher education for the Huygens grant. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.
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Online Material
Appendix A: Relations between kinematic (ir)regularity parameters
![]() |
Figure A.1:
(Ir)regularity parameters versus each other. The regularity threshold
of each parameter is shown with a dashed line. The galaxies in the
local sample are used only for determination of the regularity
thresholds as explained in Paper III. They are not used in
correlation measurements. The galaxies that are excluded from the
correlation as explained in Sect. 3.8 are indicated
with their names on the plot. a) Standard
deviation of the kinematic position angle (
|
Open with DEXTER |
Appendix B: Individual galaxies
Here we present some figures showing the data and its analysis for each object in our sample. The HST image and the velocity field of each galaxy have the same orientation (the slit position is parallel to the x-axis). The velocities and the positions are given with respect to the continuum center of the galaxies.
B.1 Cluster galaxies
![]() |
Figure B.1:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. e) H |
Open with DEXTER |
![]() |
Figure B.2:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. e) H |
Open with DEXTER |
![]() |
Figure B.3:
a) HST-ACS image of the galaxy in
the V band. b) Rotation
curves of different emission lines extracted along the central slit.
c) Position angles of kinematic and photometric axes
as a function of radius. d) Rotation
curves extracted along the central slit and the kinematic major axis.
e) H |
Open with DEXTER |
![]() |
Figure B.4: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the centralslit. |
Open with DEXTER |
![]() |
Figure B.5:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER |
![]() |
Figure B.6: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.7: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OIII]5007 velocity field. f.1) Normalized [OII]3727 flux map. f.2) Normalized [OIII]5007 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.8:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER |
![]() |
Figure B.9:
a) HST-ACS image of the galaxy in the V band.
e) H |
Open with DEXTER |
![]() |
Figure B.10:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. e) H |
Open with DEXTER |
![]() |
Figure B.11:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER |
![]() |
Figure B.12:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER |
![]() |
Figure B.13:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER |
![]() |
Figure B.14: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.15:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER |
![]() |
Figure B.16: a.1) HST-ACS image of the galaxy in the V band. a.2) This cluster galaxy does not have emission lines. The spectra include an emission line from the galaxy below the target that is seen in the HST image. The redshift of this galaxy could not be determined from the composite spectrum. a.3) FORS2 image of the galaxies. Parallel lines represent the bottom slit which gives a composite spectrum of both galaxies together. b) Rotation curve of the galaxy that is below the target. It is obtained from the slit positioned inbetween the two galaxies (see a.3)). Velocities were measured with respect to the velocity at the continuum center of the bottom slit. Signal level in the other two slits was not high enough to obtain a rotation curve. |
Open with DEXTER |
![]() |
Figure B.17:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OII]3727 velocity
field. f.1) Normalized H |
Open with DEXTER |
![]() |
Figure B.18: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
B.2 Field galaxies
![]() |
Figure B.19:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER |
![]() |
Figure B.20: a) HST-ACS image of the galaxy in the V band. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) Velocity field constructed using the emission line which could not be identified. f) Normalized flux map of the emission line which could not be identified. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.21: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.22: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.23: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.24:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER |
![]() |
Figure B.25: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. |
Open with DEXTER |
![]() |
Figure B.26: a) HST-ACS image of the galaxy in the V band. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. |
Open with DEXTER |
![]() |
Figure B.27:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER |
![]() |
Figure B.28:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER |
![]() |
Figure B.29:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER |
![]() |
Figure B.30: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.31: a) HST-ACS image of the galaxy in the V band. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. |
Open with DEXTER |
![]() |
Figure B.32: a) HST-ACS image of the galaxy in the V band. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. |
Open with DEXTER |
![]() |
Figure B.33: a) HST-ACS image of the objects in the V band. c) Position angle of the kinematic axis as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) Velocity field of the emission line which could not be identified. The map belongs to 2F15 and 2F16 together. f) Normalized flux map of the emission line which could not be identified. The map belongs to 2F15 and 2F16 together. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.34: a.1) HST-ACS image of the galaxy in the V band. a.2) Image showing the galaxy together with its companion. b) Rotation curves of different emission lines extracted along the central slit. e) [OIII]5007 velocity field. f) Normalized [OIII]5007 flux map. |
Open with DEXTER |
![]() |
Figure B.35: a) HST-ACS image of the galaxy in the V band. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. |
Open with DEXTER |
![]() |
Figure B.36: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OIII]5007 velocity field. f) Normalized [OIII]5007 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.37: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. |
Open with DEXTER |
![]() |
Figure B.38: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. |
Open with DEXTER |
![]() |
Figure B.39:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER |
![]() |
Figure B.40:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER |
![]() |
Figure B.41:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OII]3727 velocity
field. f.1) Normalized H |
Open with DEXTER |
![]() |
Figure B.42:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER |
![]() |
Figure B.43: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. |
Open with DEXTER |
![]() |
Figure B.44: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. |
Open with DEXTER |
![]() |
Figure B.45: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.46: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OIII]5007 velocity field. f) Normalized [OIII]5007 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.47: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.48: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.49: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.50:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER |
![]() |
Figure B.51: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OIII]5007 velocity field. f) Normalized [OIII]5007 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER |
![]() |
Figure B.52: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. |
Open with DEXTER |
![]() |
Figure B.53: a) HST-ACS image of the galaxy in the V band. e) Velocity field constructed using the emission line which could not be identified. f) Normalized flux map of the emission line which could not be identified. |
Open with DEXTER |
![]() |
Figure B.54:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OII]3727 velocity
field. f.1) Normalized H |
Open with DEXTER |
![]() |
Figure B.55: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OIII]5007 velocity field. f) Normalized [OIII]5007 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
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![]() |
Figure B.56: V band HST-ACS image of galaxies that have very weak or no emission. |
Open with DEXTER |
Appendix C: Photometric tables
Table C.1: Photometric parameters for the whole sample.
Table C.2: Morphological parameters for the MS 1008, MS 2137 and Cl 0413 samples.
Footnotes
- ... field
- Based on observations collected at the European Southern Observatory (ESO), Cerro Paranal, Chile (ESO Nos. 74.B-0592 & 75.B-0187) and observations of the Hubble Space Telescope (HST No 10635).
- ...
- Appendices are only available in electronic form at http://www.aanda.org
- ...R
- The FORS2 filter curves are given at http://www.eso.org/instruments/fors/inst/Filters/curves.html
All Tables
Table 1: Basic galaxy cluster information.
Table 2:
K-S statistics of H
luminosities of our sample and the local sample.
Table 3: Basic galaxy information.
Table 4: Eye-ball morphological classification of the MS 0451 sample.
Table 5: Photometric parameters for the SINGS sample.
Table 6: K-S statistics of the morphological parameters of our sample and the local sample.
Table 7: Parameters quantifying the (ir)regularity of the gas kinematics measured for our sample.
Table 8:
H
luminosities.
Table 9: K-S statistics of (ir)regularity parameters of the cluster and field galaxies in our sample.
Table 10: K-S statistics comparing the kinematic (ir)regularity parameters of the galaxies in our sample classified as spiral or irregular/ peculiar using their photometry.
Table 11: Linear Pearson correlation coefficients.
Table 12: Irregularity fraction.
Table 13: Possible dynamical pairs.
Table 14: K-S statistics of (ir)regularity parameters of the cluster and field galaxies in our sample, excluding possible dynamical pairs.
Table C.1: Photometric parameters for the whole sample.
Table C.2: Morphological parameters for the MS 1008, MS 2137 and Cl 0413 samples.
All Figures
![]() |
Figure 1:
Distribution of H |
Open with DEXTER | |
In the text |
![]() |
Figure 2: Distribution of morphological parameters for our sample and the local sample. a) Concentration parameter. b) Asymmetry parameter. c) Gini coefficient. d) M20 index. |
Open with DEXTER | |
In the text |
![]() |
Figure 3: Distribution of galaxies in our sample and a local sample from SINGS on the A-C plane. Their morphological types, that are determined by our eye-ball classification (Table 3, Col. 7), are indicated with different symbols as shown in the legend. The dash-dotted green lines are the selection limits separating different morphological types determined by Menanteau et al. (2006). The borders that are adjusted by minimizing the amount of contamination from different types in each region are shown with black dotted lines. |
Open with DEXTER | |
In the text |
![]() |
Figure 4:
SFR versus stellar mass for our sample and the local sample from SINGS.
The SFR-stellar mass relation based on |
Open with DEXTER | |
In the text |
![]() |
Figure 5: Specific star formation rate versus rest-frame B-V color for our sample and the local sample from SINGS. |
Open with DEXTER | |
In the text |
![]() |
Figure 6: Histograms of the emission line flux ratios. |
Open with DEXTER | |
In the text |
![]() |
Figure 7:
Histograms of the mean misalignment between kinematic and photometric
major axes (
|
Open with DEXTER | |
In the text |
![]() |
Figure 8:
Histograms of the mean misalignment between the kinematic and
photometric major axes (
|
Open with DEXTER | |
In the text |
![]() |
Figure 9:
(Ir)regularity parameters versus
|
Open with DEXTER | |
In the text |
![]() |
Figure 10:
a) H |
Open with DEXTER | |
In the text |
![]() |
Figure 11:
(Ir)regularity parameters versus some photometric quantities. For each
plot, the line shows the correlation between the given parameters. The
local galaxies are not used in correlation measurements, but shown as a
reference in each plot. The names that are written in red and italic
belong to the galaxies that are excluded from the correlation as
explained in Paper III for the MS 0451 sample and
here, in Sect. 3.8
for the rest. a) M20 index
versus the mean misalignment between the photometric and kinematic
major axes (
|
Open with DEXTER | |
In the text |
![]() |
Figure 12:
Number distribution of the |
Open with DEXTER | |
In the text |
![]() |
Figure 13:
|
Open with DEXTER | |
In the text |
![]() |
Figure A.1:
(Ir)regularity parameters versus each other. The regularity threshold
of each parameter is shown with a dashed line. The galaxies in the
local sample are used only for determination of the regularity
thresholds as explained in Paper III. They are not used in
correlation measurements. The galaxies that are excluded from the
correlation as explained in Sect. 3.8 are indicated
with their names on the plot. a) Standard
deviation of the kinematic position angle (
|
Open with DEXTER | |
In the text |
![]() |
Figure B.1:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.2:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.3:
a) HST-ACS image of the galaxy in
the V band. b) Rotation
curves of different emission lines extracted along the central slit.
c) Position angles of kinematic and photometric axes
as a function of radius. d) Rotation
curves extracted along the central slit and the kinematic major axis.
e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.4: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the centralslit. |
Open with DEXTER | |
In the text |
![]() |
Figure B.5:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.6: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.7: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OIII]5007 velocity field. f.1) Normalized [OII]3727 flux map. f.2) Normalized [OIII]5007 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.8:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.9:
a) HST-ACS image of the galaxy in the V band.
e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.10:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.11:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.12:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER | |
In the text |
![]() |
Figure B.13:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER | |
In the text |
![]() |
Figure B.14: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.15:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER | |
In the text |
![]() |
Figure B.16: a.1) HST-ACS image of the galaxy in the V band. a.2) This cluster galaxy does not have emission lines. The spectra include an emission line from the galaxy below the target that is seen in the HST image. The redshift of this galaxy could not be determined from the composite spectrum. a.3) FORS2 image of the galaxies. Parallel lines represent the bottom slit which gives a composite spectrum of both galaxies together. b) Rotation curve of the galaxy that is below the target. It is obtained from the slit positioned inbetween the two galaxies (see a.3)). Velocities were measured with respect to the velocity at the continuum center of the bottom slit. Signal level in the other two slits was not high enough to obtain a rotation curve. |
Open with DEXTER | |
In the text |
![]() |
Figure B.17:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OII]3727 velocity
field. f.1) Normalized H |
Open with DEXTER | |
In the text |
![]() |
Figure B.18: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.19:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.20: a) HST-ACS image of the galaxy in the V band. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) Velocity field constructed using the emission line which could not be identified. f) Normalized flux map of the emission line which could not be identified. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.21: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.22: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.23: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.24:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.25: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. |
Open with DEXTER | |
In the text |
![]() |
Figure B.26: a) HST-ACS image of the galaxy in the V band. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. |
Open with DEXTER | |
In the text |
![]() |
Figure B.27:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER | |
In the text |
![]() |
Figure B.28:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER | |
In the text |
![]() |
Figure B.29:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.30: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.31: a) HST-ACS image of the galaxy in the V band. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. |
Open with DEXTER | |
In the text |
![]() |
Figure B.32: a) HST-ACS image of the galaxy in the V band. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. |
Open with DEXTER | |
In the text |
![]() |
Figure B.33: a) HST-ACS image of the objects in the V band. c) Position angle of the kinematic axis as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) Velocity field of the emission line which could not be identified. The map belongs to 2F15 and 2F16 together. f) Normalized flux map of the emission line which could not be identified. The map belongs to 2F15 and 2F16 together. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.34: a.1) HST-ACS image of the galaxy in the V band. a.2) Image showing the galaxy together with its companion. b) Rotation curves of different emission lines extracted along the central slit. e) [OIII]5007 velocity field. f) Normalized [OIII]5007 flux map. |
Open with DEXTER | |
In the text |
![]() |
Figure B.35: a) HST-ACS image of the galaxy in the V band. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. |
Open with DEXTER | |
In the text |
![]() |
Figure B.36: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OIII]5007 velocity field. f) Normalized [OIII]5007 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.37: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. |
Open with DEXTER | |
In the text |
![]() |
Figure B.38: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. |
Open with DEXTER | |
In the text |
![]() |
Figure B.39:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.40:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.41:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OII]3727 velocity
field. f.1) Normalized H |
Open with DEXTER | |
In the text |
![]() |
Figure B.42:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) H |
Open with DEXTER | |
In the text |
![]() |
Figure B.43: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. |
Open with DEXTER | |
In the text |
![]() |
Figure B.44: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. |
Open with DEXTER | |
In the text |
![]() |
Figure B.45: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.46: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OIII]5007 velocity field. f) Normalized [OIII]5007 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.47: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.48: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.49: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OII]3727 velocity field. f) Normalized [OII]3727 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.50:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OIII]5007 velocity
field. f.1) Normalized H |
Open with DEXTER | |
In the text |
![]() |
Figure B.51: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OIII]5007 velocity field. f) Normalized [OIII]5007 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.52: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. |
Open with DEXTER | |
In the text |
![]() |
Figure B.53: a) HST-ACS image of the galaxy in the V band. e) Velocity field constructed using the emission line which could not be identified. f) Normalized flux map of the emission line which could not be identified. |
Open with DEXTER | |
In the text |
![]() |
Figure B.54:
a) HST-ACS image of the galaxy in the V band.
b) Rotation curves of different
emission lines extracted along the central slit. c) Position
angles of kinematic and photometric axes as a function of radius.
d) Rotation curves extracted along the central slit
and the kinematic major axis. e) [OII]3727 velocity
field. f.1) Normalized H |
Open with DEXTER | |
In the text |
![]() |
Figure B.55: a) HST-ACS image of the galaxy in the V band. b) Rotation curves of different emission lines extracted along the central slit. c) Position angles of kinematic and photometric axes as a function of radius. d) Rotation curves extracted along the central slit and the kinematic major axis. e) [OIII]5007 velocity field. f) Normalized [OIII]5007 flux map. g) Velocity map reconstructed using 6 harmonic terms. h) Residual of the velocity map and the reconstructed map. i) Simple rotation map constructed for position angle and ellipticity fixed to their global values. j) Residual of the velocity map and the simple rotation map. k) Position angle and flattening as a function of radius. l) k3/k1 and k5/k1 (from the analysis where position angle and ellipticity are fixed to their global values) as a function of radius. |
Open with DEXTER | |
In the text |
![]() |
Figure B.56: V band HST-ACS image of galaxies that have very weak or no emission. |
Open with DEXTER | |
In the text |
Copyright ESO 2010
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