All Figures

$\begin{figure} \par\includegraphics[width=7.7cm,clip]{1583f1.eps} \end{figure}$ Figure 1: Map of the central Hydra cluster, with distances relative to NGC 3311. Large squares are the observed VLT fields, the field number is indicated in the lower right corner of each square. Dots are all Hydra cluster member galaxies from the spectroscopic study of Christlein & Zabludoff (2003). Galaxies marked with large circles are the ones for which we present new SBF measurements in this paper. The cluster members without SBF measurement are 11 late-type and 8 early-type galaxies.
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In the text

$\begin{figure} \par\mbox{\includegraphics[width=4.8cm,clip]{1583f2_1.ps}\hspace{... ...}\hspace{0.2cm} \includegraphics[width=5.2cm,clip]{1583f2_6.eps} }\end{figure}$ Figure 2: Plots illustrating the effect of the window function effect. Upper panels: the inner ring of NGC 3311. Lower panels: galaxy 258 in field 1. Left panels: mask image used to blend out contaminating sources and restrict the measurement region. Masked regions are black. Middle panels: power spectrum of the mask on the left image. Right panels: filled circles: power spectrum of an isolated star, normalised to unity at wavenumber k=0. Crosses: the same power spectrum convolved with the mask power spectrum from the middle panels. The convolved power spectrum is lower than the non-convolved one by about 0.2 mag for NGC 3311 and about 0.4 mag for galaxy 258, corresponding to the values derived with the SBF simulations (see Table 4 and Sect. 2.2.1).
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{1583f3.eps} \end{figure}$ Figure 3: Incompleteness corrected globular cluster luminosity functions of the four indicated galaxies in the rings where SBF were measured. Asterisks with error bars are counts in the I-band, filled squares are counts in the V-band shifted to I assuming (V-I)=1.04 from Kundu & Whitmore (2001). The number counts are corrected for background contamination and shown up to the faintest magnitude bin for which the completeness was above 50%. The solid lines are Gaussian fits, whose parameters are the mean of the values fit independently in V and I. The derived turnover magnitudes and specific frequencies S_N are given in Table. 3.
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In the text

$\begin{figure} \par\includegraphics[width=7.6cm,clip]{1583f4.eps} \end{figure}$ Figure 4: CMB rest-frame radial velocity is plotted vs. SBF distance for the Hydra galaxies investigated in this paper (filled circles) and the revised Centaurus galaxies from Mieske & Hilker (2003) (open circles). The solid line gives the Hubble flow for $H_{\rm0}=70$ km s^-1 Mpc^-1. The upper dashed line corresponds to $H_{\rm0}=60$ , the lower dashed line to $H_{\rm0}=80$ .
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In the text

$\begin{figure} \par\includegraphics[width=8.7cm,clip]{1583f5.eps} \end{figure}$ Figure 5: Left panels: distance modulus $(m-M)_{\rm SBF}$ of the Hydra galaxies plotted vs. their absolute magnitude M_V ( bottom) and colour (V-I) ( top). The mean distance modulus with its 1 $\sigma$ error is indicated by the solid and dashed vertical lines. The dashed horizontal lines in the top panel indicate the colour range of the empirical SBF calibration by Tonry et al. (2001). The data points outside this colour range are marked by open circles in the lower panel. Right panels: plot of the same entities as in the left panels for the revised Centaurus cluster distances.
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In the text

$\begin{figure} \par\includegraphics[width=7.9cm,clip]{1583f6.eps} \end{figure}$ Figure 6: Positions in super-galactic coordinates of the following objects: Great Attractor (GA) according to Tonry et al. (2000, T00 in the following) as filled circle; Hydra cluster as open circle at $\simeq$ (140, -38); Centaurus cluster as open circle at $\simeq$ (156, -12). The indicated GA distance of 43 Mpc is from T00, the Centaurus distance is based on Mieske & Hilker (2003) and revised in this paper. The Hydra distance is from this paper. Crosses and the attributed numbers indicate assumed projected positions of the GA for which the expected CMB radial velocities of Hydra and Centaurus are shown in Fig. 7, as calculated with the flow model by T00. The dashed circle delimits the region into which the projected position of the GA from T00 must be shifted to explain the observed distances and CMB velocities for Hydra and Centaurus, see Figs. 7 and 8. The GA can be accommodated in the entire circle region for a distance of $\simeq$ 47 Mpc.
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In the text

$\begin{figure} \par\mbox{\includegraphics[width=3.9cm,clip]{1583f7_1.eps}\hspace... ...s}\hspace*{1mm} \includegraphics[width=3.9cm,clip]{1583f7_4.eps} }\end{figure}$ Figure 7: Comparison between expected and measured CMB radial velocities for four different GA distances of 43, 45, 47 and 49 Mpc. The x-axes indicates the different projected GA positions from Fig. 6. Filled circles: expected CMB radial velocity for the Centaurus cluster based on the flow model by Tonry et al. (2000), using the Centaurus distance of this paper. Crosses: expected CMB radial velocities for Hydra, using the Hydra distance of this paper. Open squares: expected CMB radial velocities for Hydra assuming a 15% higher Hydra distance of 47 Mpc. Filled triangles: expected CMB radial velocities for Centaurus assuming a 15% lower Centaurus distance of 39 Mpc. Error bars have been omitted for these two sets of expected velocities. Upper horizontal solid line: CMB rest-frame radial velocity of the Hydra cluster (Christlein & Zabludoff 2003). Lower horizontal solid line: CMB rest-frame radial velocity of the Centaurus cluster (Stein et al. 1997). The dashed horizontal lines indicate the respective error ranges.
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In the text

$\begin{figure} \par\includegraphics[width=7cm,clip]{1583f8.eps} \end{figure}$ Figure 8: Face-on view towards a plane defined by the positions of Centaurus, Hydra and the Sun, with the Sun being the origin. We assume $H_{\rm0}=72$ km s^-1 Mpc^-1 to convert distance to CMB redshift. The dotted meridian lines are separated by 10 $\hbox {$^\circ $ }$ . The positions of the Centaurus and Hydra cluster are indicated as circles with solid lines, using the distances derived in this paper. The dotted circle indicates the Cen30 distance derived by Tonry et al. (2001). The symbol sizes corresponds to the distance uncertainties. The position of the Great Attractor from Tonry et al. (2000) is indicated by the filled circle. The peculiar velocities derived in this paper for Hydra and Centaurus are indicated by the arrows. The area within which the Tonry et al. Great Attractor can be accommodated in the light of our new peculiar velocity measurements is indicated by the shaded area, see also Figs. 6 and 7.
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{1583f9.eps} \end{figure}$ Figure 9: Literature comparison of distances to the Hydra cluster. Numbers refer to the following sources: 1 SBF distance from this paper; 2 mean I-band SBF distance to NGC 3309 and NGC 3311 from Blakeslee et al. (2002, and priv. comm.); 3 mean FP distance to NGC 3309 and NGC 3311 from Blakeslee et al. (2002); 4 mean K-band SBF distance to NGC 3309 and NGC 3311 from Jensen et al. (1999); 5 NICMOS F160W SBF-distance to NGC 3309 from Jensen et al. (2001) using the revised calibration by Jensen et al. (2003); 6 FP distance to Hydra cluster from Hudson et al. (2004), open symbol refers to the distance when including the Mg₂ term in the FP-relation fit.
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In the text

$\begin{figure} \par\includegraphics[width=7.7cm,clip]{1583f10.eps} \end{figure}$ Figure 10: Deredenned colour (V-I)₀ plotted vs. apparent fluctuation magnitude $\overline {m}_{I}$ for the investigated Hydra galaxies. Large squares indicate the results obtained in the three different rings for NGC 3309; large triangles refer to NGC 3311; the two crosses for the galaxy with $(V-I)_0\simeq 1.09$ mag refer to galaxy No. 252 in field 3, which was also imaged and investigated in the adjacent field 2. The solid line indicates the calibration relation adopted between $\overline {M}_I$ and (V-I)₀, shifted to (m-M)=33.07 mag, see Sect. 2.2. The dashed line is a linear fit to the data points, allowing both the zero-point and slope to vary. The fitted slope varies by 0.9 $\sigma$ from the slope adopted in the calibration.
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In the text

$\begin{figure} \par\includegraphics[width=7.6cm,clip]{1583f4.eps} \end{figure}$	Figure 4: CMB rest-frame radial velocity is plotted vs. SBF distance for the Hydra galaxies investigated in this paper (filled circles) and the revised Centaurus galaxies from Mieske & Hilker (2003) (open circles). The solid line gives the Hubble flow for $H_{\rm0}=70$ km s^-1 Mpc^-1. The upper dashed line corresponds to $H_{\rm0}=60$ , the lower dashed line to $H_{\rm0}=80$ .
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