- ID:
- ivo://CDS.VizieR/J/A+A/593/A2
- Title:
- Red-sequence early-type galaxies in clusters
- Short Name:
- J/A+A/593/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out a photometric and structural analysis in the rest-frame V band of a mass-selected (logM/M_{sun}_>10.7) sample of red sequence galaxies in 14 galaxy clusters, six of which are at z>1.45, namely JKCS041, IDCS J1426.5+3508, SpARCS104922.6+564032.5, SpARCSJ022426-032330, XDCPJ0044.0-2033, and SPT-CLJ2040-4451. To this aim, we reduced/analysed about 300 orbits of multicolor images taken with the Advanced Camera for Survey and the Wide Field Camera 3 on Hubble Space Telescope. We uniformly morphologically classified galaxies from z=0.023 to z=1.803, and we homogeneously derived sizes (effective radii) for the entire sample. Furthermore, our size derivation allows, and therefore is not biased by, the presence of the usual variety of morphological structures seen in early-type galaxies, such as bulges, bars, disks, isophote twists, and ellipticity gradients. By such a mass-selected sample, composed of 244 red-sequence early-type galaxies, we find that the log of the galaxy size at a fixed stellar mass, logM/M_{sun}_=11 increases with time with a rate of 0.023+/-0.002dex per Gyr in the last 10Gyr, in marked contrast with the threefold increase found in literature for galaxies in the general field over the same period. This suggests, at face value, to exclude that secular processes are the primary drivers of size evolution, because we observed and environmental environmental dependent size growth. Using spectroscopic ages of Coma early-type galaxies we also find that recently quenched early-type galaxies are a numerically minor population not different in size enough to alter the mean size at a given mass, which implies that the progenitor bias is minor, i.e. that the evolution measured by selecting galaxies at the redshift of observation is indistinguishable from the one that compares ancestors and descendents.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/490/945
- Title:
- Redshifs of galaxies in 23 EIS fields
- Short Name:
- J/A+A/490/945
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a spectroscopic survey of low-redshift galaxy systems identified by the matched-filter technique in a moderately deep I-band survey. We present new redshifts for 747 galaxies in 23 ESO Imaging Survey (EIS) cluster fields. We use the "gap"-technique to search for significant overdensities in redshift space for identifying groups/clusters of galaxies corresponding to the original EIS matched-filter cluster candidates. In this way we spectroscopically confirm systems in 10 of the 23 cluster candidate fields with a matched-filter estimated redshift z_MF_=0.3-0.4 and with spectroscopic redshifts in the range from z=0.158 to z=0.534, with the observations favouring the confirmation of systems at the lower redshift end. After careful analysis of the redshift distribution, one system was split into two very close clumps in redshift space. We find that the systems identified in the present paper span a broad range of velocity dispersion and richness. The measured one-dimensional velocity dispersion range from 175km/s to 497km/s, consistent with the values obtained in previous papers using much larger samples for systems over the same redshift range. Both undersampling and contamination by substructures contribute to the uncertainty of these measurements. The richness range corresponds to clusters with an estimated total luminosity in the range 12L^*^-65L^*^, but these estimates are very uncertain as are their relation to the velocity dispersion (mass) of the systems. From the analysis of the colours of the galaxy populations we find that ~60% of the spectroscopically confirmed systems have a "significant" red sequence. We find that the colour of the red sequence galaxies matches passive stellar evolution predictions. With this paper we complete our spectroscopic survey of the fields of 58 EIS cluster candidates with estimated redshifts z<=0.4 (see also Hansen et al., 2002, Cat. <J/A+A/388/1>; Olsen et al., 2003, Cat. <J/A+A/409/439>, Olsen et al., 2005, Cat. <J/A+A/435/781>). We have measured a total of 1954 galaxy redshifts in the range z=0.0065 to z=0.6706. Of the 58 systems we confirm 42 (~75%) with redshifts between z=0.095 and z=0.534.
- ID:
- ivo://CDS.VizieR/J/A+A/635/A98
- Title:
- Redshift catalogs of the Abell 2163 core
- Short Name:
- J/A+A/635/A98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Abell 2163 at z~=0.201 is one of the most massive galaxy clusters known, very likely in a post-merging phase. Data from several observational windows suggest a complex mass structure with interacting subsystems, which makes the reconstruction of a realistic merging scenario very difficult. A missing key element in this sense is unveiling the cluster mass distribution at high resolution. We perform such a reconstruction of the cluster inner total mass through a strong lensing model based on new spectroscopic redshift measurements. We use data from the Multi Unit Spectroscopic Explorer on the Very Large Telescope to confirm 12 multiple images of four sources with redshift values from 1.16 to 2.72. We also discover four new multiple images and identify 29 cluster members and 35 foreground and background sources. The resulting galaxy member and image catalogs are used to build five cluster total mass models. The fiducial model consists of 111 small-scale subhalos, plus a diffuse component, which is centered ~2" away from the BCG belonging to the east Abell 2163 subcluster. We confirm that the latter is well represented by a single, large-scale mass component. Its strong elongation towards a second (west) subcluster confirms the existence of a preferential axis, corresponding to the merging direction. From the fiducial model, we extrapolate the cumulative projected total mass profile and measure a value of M(<300kpc)=1.43_-0.06_^+0.07^x10^14^M_{sun}_, which has a significantly reduced statistical error compared with previous estimates, thanks to the inclusion of the spectroscopic redshifts. Our strong lensing results are very accurate: the model-predicted positions of the multiple images are, on average, only 0.15" away from the observed ones.
- ID:
- ivo://CDS.VizieR/J/A+A/638/A27
- Title:
- Redshift database towards Shapley Supercluster
- Short Name:
- J/A+A/638/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a database and velocity catalogue towards the region of the Shapley Supercluster based on 18,129 measured velocities for 10,702 galaxies in the approximately 300 square degree area between 12:42:13.219<RA<14:16:59.210 and -38:29:35.70<Dec<-23:28:34.90. The data catalogue contains velocities from the literature found until 2015. It also includes 5,084 velocities, corresponding to 4617 galaxies, observed by us at Las Campanas and CTIO observatories and not reported individually until now. Of these, 2585 correspond to galaxies with no other previously published velocity measurement before 2015. Every galaxy in the velocity database has been identified with a galaxy extracted from the SuperCOSMOS photometric catalogues. We also provide a combined average velocity catalogue for all 10702 galaxies with measured velocities, adopting the SuperCOSMOS positions as a homogeneous base. A general magnitude cut-off at R2=18.0mag was adopted (with exceptions only for some of the new reported velocities). In general terms, we confirm the overall structure of the Shapley Supercluster, as found on earlier papers. However, the more extensive velocity data show finer structure, to be discussed in a future publication.
- ID:
- ivo://CDS.VizieR/J/A+A/479/1
- Title:
- Redshifts and morphology in A3667
- Short Name:
- J/A+A/479/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The galaxy cluster A3667 was observed using the Two-degree Field (2dF) multifibre spectroscopic system on the Anglo-Australian Telescope in a program designed to examine the velocity structure in the region. Specifically, we sought evidence from the optical data for the putative cluster merger believed to be responsible for the observed radio and X-ray emission. We present 184 new redshifts in the region, of which 143 correspond to member galaxies of A3667. We find the cluster velocity distribution to be well modelled by a single Gaussian in agreement with previous results. In addition, new redshift-selected isodensity plots significantly reduce the prominence of the previously reported subgroup to the north-west of the main cluster. Instead, we find the galaxy distribution to be elongated and well mixed, with a high velocity dispersion and no significant evidence for substructure. These results are consistent with the axis of the proposed merger being close to the plane of the sky.
- ID:
- ivo://CDS.VizieR/J/AJ/132/347
- Title:
- Redshifts and photometry in Centaurus cluster
- Short Name:
- J/AJ/132/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We acquired spectra for a random sample of galaxies within a 0.83deg^2^ region centered on the core of the Centaurus Cluster. Radial velocities were obtained for 225 galaxies to limiting magnitudes of V<19.5. Of the galaxies for which velocities were obtained, we find 35% to be member galaxies. New redshifts are obtained for 15 Centaurus Cluster members, many of them dwarf galaxies. Radial velocities for the other members agree well with those from previous studies. Of the 78 member galaxies, magnitudes range over 11.8<V<18.5 (-21.6<M_V_<-14.9 for H0=70km/s/Mpc), with a limiting central surface brightness of {mu}0<22.5mag/arcsec^2^. While many of these galaxies are giants, about 25 galaxies with M_V_>-17.0 are considered dwarfs. We constructed the cluster galaxy luminosity function (LF) by using these spectroscopic results to calculate the expected fraction of cluster members in each magnitude bin. The faint-end slope of the LF using this method is shallower than the one obtained using a statistical method to correct for background galaxy contamination. We also use the spectroscopy results to define surface brightness criteria to establish membership for the full sample. Using these criteria, we find a LF very similar to the one constructed with the statistical background correction.
- ID:
- ivo://CDS.VizieR/J/A+A/492/345
- Title:
- Redshifts and SDSS photometry of A1942 galaxies
- Short Name:
- J/A+A/492/345
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a dynamical analysis of the galaxy cluster Abell 1942 based on a set of 128 velocities obtained at the European Southern Observatory. Data on individual galaxies are presented and the accuracy of the determined velocities as some properties of the cluster are discussed. We have also made use of publicly available Chandra X-ray data.
- ID:
- ivo://CDS.VizieR/VII/177
- Title:
- Redshifts and Velocity Dispersions for Abell Clusters
- Short Name:
- VII/177
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog presents a list of redshifts for 758 Abell clusters, and velocity dispersions for 121, published as of 1991 March. We present another list of 33 Abell clusters with published redshifts, most of which are probably redshifts of foreground or background galaxies superposed on, or near, the Abell clusters. Over the past 4 years, the published number of redshifts of member galaxies in clusters increased by a factor of 2.0, but the number of cluster redshifts increased by only a factor of 1.3, while the number of cluster velocity dispersions derived from 50 or more redshifts of member galaxies increased by a factor of 3.8 (from 6 to 23).
- ID:
- ivo://CDS.VizieR/VII/56
- Title:
- Redshifts for Abell Clusters
- Short Name:
- VII/56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog gives redshifts for 329 Abell clusters, all those known to the authors in published or preprint form at the time of the compilation (through 1982). The data table has been compiled critically, based partially on a number of photometric distance estimators derived from the redshift data. These were used to evaluate probable accuracies of the redshifts and to resolve discrepancies among different values for the same clusters. The catalog includes Abell (1958) cluster numbers, redshifts, and the number of redshifts of different galaxies averaged to determine the cluster value. The machine version was prepared at the Astronomical Data Center, NASA/GSFC. Note that Struble and Rood published further compilations in 1987 (1987ApJS...63..543S) and 1991 (1991ApJS...77..363S). Other redshift compilations are also available in electronic form (see "See also" section below).
- ID:
- ivo://CDS.VizieR/VII/71
- Title:
- Redshifts for Zwicky's Near Clusters
- Short Name:
- VII/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains a list of redshifts for Zwicky's Near Clusters. All of the 503 Zwicky Near Clusters as given in the Uppsala General Catalogue of Galaxies (UGC) are listed and radial velocity information for those that have at least one galaxy with published redshift positioned within the contours given in the Zwicky catalog is provided. Redshifts of galaxies belonging to clusters is obtained from the catalog of Radial Velocities of Galaxies. The catalog includes UGC cluster numbers, Zwicky field numbers, contour numbers, positions, heliocentric cluster radial velocities, and notes.
