Issue |
A&A
Volume 433, Number 1, April I 2005
|
|
---|---|---|
Page(s) | 31 - 41 | |
Section | Cosmology (including clusters of galaxies) | |
DOI | https://doi.org/10.1051/0004-6361:20041879 | |
Published online | 14 March 2005 |
Structure of visible and dark matter components in spiral galaxies at
redshifts z
1
Institute of Theoretical Physics, Tartu University, Tähe 4, Tartu 51010, Estonia e-mail: [atamm;ptenjes]@ut.ee
2
Tartu Observatory, Tõravere, Tartumaa 61602, Estonia
Received:
23
August
2004
Accepted:
29
November
2004
We have constructed self-consistent light and mass distribution
models for four disk galaxies at redshifts 0.58, 0.81
and 0.88, using the HST archive WFPC2 observations (HDF-S, MDS,
Groth Strip survey) and rotation curves measured by Vogt et al.
([CITE]) and Rigopoulou et al. ([CITE]). The models
consist of three components: a bulge, a disk and a dark matter
halo. Similarly to the sample studied in Paper I (Tamm & Tenjes [CITE]), light distribution of the galaxies in the outer parts is clearly steeper than a simple exponential disk. After
applying k-corrections, calculated mass-to-light ratios for
galactic disks within the maximum disk assumption are
0.9, 7.4, 4.3 and 1.4, respectively. Together with the galaxies from Paper I, the mean
2.5 at
, indicating no significant evolution of
with redshift. Central densities of dark matter halos for an isothermal model are 0.008, 0.035, 0.013, and 0.022 in units
respectively. Together with the galaxies
from Paper I, the DM central density of the four galaxies at mean
readshift
is
also showing no significant
evolution with redshift.
We have also constructed mass distribution models without assuming
flat rotation curves and without a dark matter component. Due to the
limited extent of the observed rotation, the models without a dark
halo nearly fit the observations. In this case, mass-to-light ratios
for the galactic disks are 1.8, 9.7, 12. and 1.9, respectively.
Key words: galaxies: photometry / galaxies: fundamental parameters / galaxies: high-redshift / galaxies: spiral / galaxies: structure / dark matter
© ESO, 2005
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