- ID:
- ivo://CDS.VizieR/J/ApJ/776/91
- Title:
- Spectroscopic redshifts of galaxies in 2 clusters
- Short Name:
- J/ApJ/776/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We provide a new observational test for a key prediction of the {Lambda}CDM cosmological model: the contributions of mergers with different halo-to-main-cluster mass ratios to cluster-sized halo growth. We perform this test by dynamically analyzing 7 galaxy clusters, spanning the redshift range 0.13<z_c_<0.45 and caustic mass range 0.4-1.5x10^15^h_0.73_^-1^M_{sun}_, with an average of 293 spectroscopically confirmed bound galaxies to each cluster. The large radial coverage (a few virial radii), which covers the whole infall region, with a high number of spectroscopically identified galaxies enables this new study. For each cluster, we identify bound galaxies. Out of these galaxies, we identify infalling and accreted halos and estimate their masses and their dynamical states. Using the estimated masses, we derive the contribution of different mass ratios to cluster-sized halo growth. For mass ratios between ~0.2 and ~0.7, we find a ~1{sigma} agreement with {Lambda}CDM expectations based on the Millennium simulations I and II. At low mass ratios, <~0.2, our derived contribution is underestimated since the detection efficiency decreases at low masses, ~2x10^14^h_0.73_^-1^M_{sun}_. At large mass ratios, >~0.7, we do not detect halos probably because our sample, which was chosen to be quite X-ray relaxed, is biased against large mass ratios. Therefore, at large mass ratios, the derived contribution is also underestimated.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/756/139
- Title:
- Spectroscopic redshifts of galaxies in groups
- Short Name:
- J/ApJ/756/139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the global group properties of two samples of galaxy groups containing 39 high-quality X-ray-selected systems and 38 optically (spectroscopically) selected systems in coincident spatial regions at 0.12<z<0.79. The total mass range of the combined sample is ~(10^12^-5)x10^14^M_{sun}_. Only nine optical systems are associable with X-ray systems. We discuss the confusion inherent in the matching of both galaxies to extended X-ray emission and of X-ray emission to already identified optical systems. Extensive spectroscopy has been obtained and the resultant redshift catalog and group membership are provided here. X-ray, dynamical, and total stellar masses of the groups are also derived and presented. We explore the effects of utilizing different centers and applying three different kinds of radial cut to our systems: a constant cut of 1Mpc and two r_200_ cuts, one based on the velocity dispersion of the system and the other on the X-ray emission.
- ID:
- ivo://CDS.VizieR/J/ApJS/211/21
- Title:
- Spectroscopic redshifts of galaxies in MACS
- Short Name:
- J/ApJS/211/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 1921 spectroscopic redshifts measured in the fields of the massive galaxy clusters MACSJ0416.1-2403 (z=0.397), MACSJ0717.5+3745 (z=0.546), and MACSJ1149.5+2223 (z=0.544), i.e., three of the four clusters selected by Space Telescope Science Institute as the targets of the Frontier Fields (FFs) initiative for studies of the distant Universe via gravitational lensing. Compiled in the course of the Massive Cluster Survey project (MACS) that detected the FF clusters, this catalog is provided to the community for three purposes: (1) to allow the identification of cluster members for studies of the galaxy population of these extreme systems, (2) to facilitate the removal of unlensed galaxies and thus reduce shear dilution in weak-lensing analyses, and (3) to improve the calibration of photometric redshifts based on both ground- and spacebased observations of the FF clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/878/66
- Title:
- Spectroscopic redshifts of gal. in SPT-CLJ0615-5746
- Short Name:
- J/ApJ/878/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of spectroscopic redshifts for SPT-CLJ0615-5746, the most distant cluster in the Reionization Lensing Cluster Survey. Using Nod & Shuffle multislit observations with LDSS-3 on Magellan, we identify ~50 cluster members and derive a cluster redshift of z_c_=0.972, with a velocity dispersion of {sigma}=1244+/-162km/s. We calculate a cluster mass using a {sigma}_200_-M_200_ scaling relation of M_200_=(9.6+/-3.5)x10^14^M_{sun}_, in agreement with previous, independent mass measurements of this cluster. In addition, we examine the kinematic state of SPT-CLJ0615-5746, taking into consideration prior investigations of this system. With an elongated profile in lensing mass and X-ray emission, a non-Gaussian velocity dispersion that increases with clustercentric radius, and a brightest cluster galaxy not at rest with the bulk of the system, there are multiple cluster properties that, while not individually compelling, combine to paint a picture that SPT-CLJ0615-5746 is currently being assembled.
- ID:
- ivo://CDS.VizieR/J/A+A/534/A31
- Title:
- Spectroscopic study of 283 AGNs in Coma
- Short Name:
- J/A+A/534/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To investigate the dependence of the occurrence of active galactic nuclei (AGNs) on local galaxy density, we study the nuclear properties of ~5000 galaxies in the Coma supercluster whose density spans two orders of magnitude from the sparse filaments to the cores of rich clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/378/1507
- Title:
- Spectroscopic study of 6 galaxies
- Short Name:
- J/MNRAS/378/1507
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an examination of the kinematics and stellar populations of a sample of three brightest group galaxies (BGGs) and three brightest cluster galaxies (BCGs) in X-ray groups and clusters. We have obtained high signal-to-noise ratio Gemini/Gemini South Multi-Object Spectrograph (GMOS) long-slit spectra of these galaxies and use Lick indices to determine ages, metallicities and alpha-element abundance ratios out to at least their effective radii. We find that the BGGs and BCGs have very uniform masses, central ages and central metallicities.
- ID:
- ivo://CDS.VizieR/J/ApJS/137/279
- Title:
- Spectroscopic Survey in Coma
- Short Name:
- J/ApJS/137/279
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second paper in a series studying the photometric and spectroscopic properties of galaxies of different luminosities in the Coma Cluster. We present the sample selection, spectroscopic observations, and completeness functions. To study the spectral properties of galaxies as a function of their local environment, two fields were selected for spectroscopic observations to cover both the core (Coma 1) and outskirts (i.e., southwest of the core and centered on NGC 4839; Coma 3) of the cluster. To maximize the efficiency of spectroscopic observations, two subsamples were defined, consisting of "bright" and "faint" galaxies, both drawn from magnitude-limited parent samples. Medium-resolution spectroscopy (6-9{AA}) was then carried out for a total of 490 galaxies in both fields (302 in Coma 1 and 188 in Coma 3), using the WYFFOS multifiber spectrograph on the William Herschel Telescope. The galaxies cover a range of 12<R<20, corresponding to -23<M_R_<-15 (H_0_=65km/s/Mpc). The redshifts for these galaxies are measured with an accuracy of 75km/s.
- 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.
- 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.
