- ID:
- ivo://CDS.VizieR/J/ApJ/498/195
- Title:
- Spectroscopic survey of CL 1358+62
- Short Name:
- J/ApJ/498/195
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic survey of the rich X-ray-selected galaxy cluster CL 1358+6245 at z=0.328. When our 173 new multislit spectra of cluster galaxies are combined with data from the literature, we produce a catalog of 232 cluster members in a region 10'x11' (3.5Mpcx3.8Mpc) surrounding the brightest cluster galaxy. These data are used to study the structure and dynamics of the cluster and to examine the radial and velocity distributions as a function of spectral type. We classify the spectral types of the cluster members according to the strengths of the Balmer absorption lines (H{delta}, H{gamma}, and H{beta}) and the [O II] 3727{AA} emission line.
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- ID:
- ivo://CDS.VizieR/J/A+A/372/391
- Title:
- Spectroscopic Survey of Cl 0024+1654
- Short Name:
- J/A+A/372/391
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This wide-field spectroscopic survey of Cl 0024+1654 (ZwCl 0024.0+1652) is based on multi-object spectroscopy done with MOS on CFHT and LDSS_2 on WHT. Photometric measurements are based on CFHT/UH8k (I-band) and CFHT/CFH12k (V-band) images. The survey covers an area of 21x25arcmin^2^ around the centre of Cl 0024+1654. The catalogue includes the data from Dressler et al., 1999, Cat. <J/ApJS/122/51> with corrections made by us. Due to additional corrections provided by Alan Dressler since the paper was accepted, the present catalogue differs slightly from the description in the paper (see Historical note below).
- ID:
- ivo://CDS.VizieR/J/ApJ/838/110
- Title:
- Spectroscopic survey of ZwCl 0008.8+5215
- Short Name:
- J/ApJ/838/110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and analyze a rich data set including Subaru/SuprimeCam, HST/Advanced Camera for Surveys and Wide Field Camera 3, Keck/DEIMOS, Chandra/ACIS-I, and JVLA/C and D array for the merging cluster of galaxies ZwCl 0008.8+5215. With a joint Subaru+HST weak gravitational lensing analysis, we identify two dominant subclusters and estimate the masses to be M_200_=5.7_-1.8_^+2.8^x10^14^M_{sun}_ and 1.2_-0.6_^+1.4^x10^14^M_{sun}_. We estimate the projected separation between the two subclusters to be 924_-206_^+243^kpc. We perform a clustering analysis of spectroscopically confirmed cluster member galaxies and estimate the line-of-sight velocity difference between the two subclusters to be 92+/-164km/s. We further motivate, discuss, and analyze the merger scenario through an analysis of the 42ks of Chandra/ACIS-I and JVLA/C and D array polarization data. The X-ray surface brightness profile reveals a merging gas-core reminiscent of the Bullet Cluster. The global X-ray luminosity in the 0.5-7.0keV band is 1.7+/-0.1x10^44^erg/s and the global X-ray temperature is 4.90+/-0.13keV. The radio relics are polarized up to 40% , and along with the masses, velocities, and positions of the two subclusters, we input these quantities into a Monte Carlo dynamical analysis and estimate the merger velocity at pericenter to be 1800_-300_^+400^km/s. This is a lower-mass version of the Bullet Cluster and therefore may prove useful in testing alternative models of dark matter (DM). We do not find significant offsets between DM and galaxies, but the uncertainties are large with the current lensing data. Furthermore, in the east, the BCG is offset from other luminous cluster galaxies, which poses a puzzle for defining DM-galaxy offsets.
- ID:
- ivo://CDS.VizieR/J/A+A/500/947
- Title:
- Spectroscopy and photometry in A2744 and A2537
- Short Name:
- J/A+A/500/947
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The current paradigm of cosmic formation and evolution of galaxy clusters foresees growth mostly through merging. Galaxies in the infall region or in the core of a cluster undergo transformations owing to different environmental stresses. For two X-ray luminous clusters at redshift z~0.3 with opposite X-ray morphologies (i.e., dynamical states), RXCJ0014.3-3022 and RXCJ2308.3-0211, we assess differences in galaxy populations as a function of cluster topography. This is a pilot study for the joint X-ray and optical analysis of the REFLEX-DXL cluster sample.
- ID:
- ivo://CDS.VizieR/J/AJ/135/1837
- Title:
- Spectroscopy in A2199 and Virgo clusters
- Short Name:
- J/AJ/135/1837
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report a new determination of the faint end of the galaxy luminosity function (LF) in the nearby clusters Abell 2199 and Virgo using data from the Sloan Digital Sky Survey (SDSS) and the Hectospec multifiber spectrograph on the MMT. The luminosity function of A2199 is consistent with a single Schechter function to M_r_=-15.6+5log(h_70_) with a faint-end slope of alpha=-1.13+/-0.07 (statistical). The LF in Virgo extends to M_r_~-13.5~M*+8 and has a slope of alpha=-1.28+/-0.06 (statistical).
- ID:
- ivo://CDS.VizieR/J/A+A/557/A62
- Title:
- Spectroscopy in Abell 3921
- Short Name:
- J/A+A/557/A62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectrophotometric analysis of the galaxy population in the area of the merging cluster Abell 3921 at z=0.093. We investigate the impact of the complex cluster environment on galaxy properties such as morphology or star formation rate. We combine multi-object spectroscopy from the Two Degree Field (2dF) spectrograph with optical imaging taken with the ESO Wide Field Imager. We carry out a redshift analysis and determine cluster velocity dispersions using biweight statistics. Applying a Dressler-Shectman test we seek evidence for cluster substructure. Cluster and field galaxies are investigated with respect to [OII] and H{alpha} equivalent width, star formation rate and morphological descriptors such as concentration index and Gini coefficient. We study these cluster galaxy properties as a function of clustercentric distance and investigate the spatial distribution of various galaxy types. Applying the Dressler-Shectman test we find a third component (A3921-C) in addition to the two main subclusters (A3921-A and A3921-B) already known. The re-determined mass ratio between the main components A and B is ~2:1. Similar to previous studies of galaxy clusters, we find that a large fraction of the disk galaxies close to the cluster core show no detectable star formation. These are likely systems that are quenched due to ram pressure stripping. Interestingly, we also find quenched spirals at rather large distances of 3-4Mpc from the cluster core.
- ID:
- ivo://CDS.VizieR/J/A+A/507/671
- Title:
- Spectroscopy in cluster RDCS J1252.9-2927 (z=1.2)
- Short Name:
- J/A+A/507/671
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent wide-field imaging observations of the X-ray luminous cluster RDCS J1252.9-2927 at z=1.24 uncovered several galaxy groups that appear to be embedded in filamentary structure extending from the cluster core. We make a spectroscopic study of the galaxies in these groups using GMOS on Gemini-South and FORS2 on VLT with the aim of determining if these galaxies are physically associated to the cluster. We find that three groups contain galaxies at the cluster redshift and that they are probably bound to the cluster. This is the first confirmation of filamentary structure as traced by galaxy groups at z>1. We then use several spectral features in the FORS2 spectra to determine the star formation histories of group galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/641/169
- Title:
- Spectroscopy in lens fields
- Short Name:
- J/ApJ/641/169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from our spectroscopic survey of strong gravitational lens environments. Six of the eight lens galaxies in our sample belong to a poor group of galaxies, three of which are newly discovered here (those associated with BRI 0952-0115, MG 1654+1346, and B2114+022).
- ID:
- ivo://CDS.VizieR/J/AJ/132/1796
- Title:
- Spectroscopy in nearby group cores
- Short Name:
- J/AJ/132/1796
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used V and I CCD photometry to search for low surface brightness dwarf galaxies in the central (<0.5h^-1^Mpc) region of the groups NGC 6868, NGC 5846, HCG 42, and the poor cluster IC 4765. We used the exponential profile fit parameters to identify 80 low surface brightness dwarf galaxy candidates with 17mag<V<22mag (-16.7>MV>-11.4), V-I<1.5mag, {mu}_0_>22.5Vmag/arcsec^2^, h>1.5", and diameters larger than 1.2h^-1^kpc. Twenty of these galaxies are extended low surface brightness galaxies that were detected only on smoothed images, after masking all high surface brightness objects. The completeness in the sample detection is ~80% for V~<20 and 22.5Vmag/arcsec^2^<{mu}_0_<24.5Vmag/arcsec^2^. For galaxies with V>20mag and {mu}_0_>24.5Vmag/arcsec^2^, the completeness is below 50% but increases to ~80% when we search for galaxies in smoothed images.
- ID:
- ivo://CDS.VizieR/J/MNRAS/381/1035
- Title:
- Spectroscopy in Shapley supercluster
- Short Name:
- J/MNRAS/381/1035
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new optical spectroscopy for 342 R<18 galaxies in the Shapley supercluster (and 198 supplementary galaxies), obtained from 8-h integrations with the AAOmega facility at the Anglo-Australian Telescope. We describe the observations and measurements of central velocity dispersion {sigma}, emission-line equivalent widths and absorption-line indices. The distinguishing characteristic of the survey is its coverage of a very wide baseline in velocity dispersion (90 per cent range {sigma}=40-230km/s), while achieving high signal-to-noise ratio throughout (median 60{AA}^-1^ at 5000{AA}). The data quality will enable estimates of Balmer-line ages to better than 20 per cent precision even for the faintest galaxies in the sample. Significant emission at H{alpha} was detected in ~30 per cent of the supercluster galaxies, including ~20 per cent of red-sequence members. Using line-ratio diagnostics, we find that the emission is LINER (low ionization nuclear emission region) like at high luminosity, but driven by star formation in low-luminosity galaxies. To characterize the absorption lines, we use the classical Lick indices in the spectral range 4000-5200{AA}. We introduce a new method for applying resolution corrections to the line-strength indices. We define a subset of galaxies with very low emission contamination, based on the H{alpha} line, and fit the index relations for this subset. The final sample analysed in this paper comprises 232 NFPS-selected galaxies meeting both the emission and the redshift criteria, of which 198 have measured velocity dispersions (i.e. are not unresolved).
