- ID:
- ivo://CDS.VizieR/VII/165A
- Title:
- Measured Redshifts of Abell Clusters of Galaxies
- Short Name:
- VII/165A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 'ACO' catalog (Abell, Corwin and Olowin 1989; Cat. VII/110) that contains 4076 rich (A-) clusters of galaxies and 1174 supplementary (S-) clusters was used to compile this catalog. In the compilation, many papers containing galaxy redshifts were checked for positional coincidences of objects with Abell clusters (typically within one Abell radius). In a total of 1059 ACO clusters a redshift for one or more galaxies were found. These 1059 clusters (records) are sorted by the R.A. (B1950) of their centre. Each record consists of cluster name, cluster centre equatorial coordinates (B1950), Abell richness, distance, Bautz-Morgan class, the magnitude of the tenth-brightest cluster member, cluster measured redshift, the reference code, the Abell radius, and the decimal log of the ratio between measured and estimated redshift.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/654/A173
- Title:
- MeerKAT 21-cm HI imaging of Abell 2626
- Short Name:
- J/A+A/654/A173
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The morphology-density relation manifests the environmental dependence of the formation and evolution of galaxies as they continuously migrate through the cosmic web to ever denser environments. As gas-rich galaxies traverse the outskirts and inner regions of galaxy clusters, they experience sudden and radical changes in their gas content and star formation activity. The goal of this work is to gain an HI perspective on gas depletion mechanisms acting on galaxies and galaxy groups that are being accreted by a moderately massive galaxy cluster. We aim to study the relative importance and efficiency of processes such as ram-pressure stripping and tidal interactions as well as their dependency on the local and global environment of galaxies in the cluster core and in its surroundings. We have conducted a blind radio continuum and Hi spectral line imaging survey with the MeerKAT radio telescope of a 2"x2" area centred on the galaxy cluster Abell 2626. We have used the CARAcal pipeline to reduce the data, SoFiA to detect sources within the Hi data cube, and GIPSY to construct spatially resolved information on the Hi morphologies and kinematics of the Hi detected galaxies. We have detected HI in 219 galaxies with optical counterparts within the entire surveyed volume. We present the HI properties of each of the detected galaxies as a data catalogue and as an atlas page for each galaxy, including HI column-density maps, velocity fields, position-velocity diagrams, and global HI profiles. These data will also be used for case studies of identified 'jellyfish' galaxies and galaxy population studies by means of morphological classification of the direct HI detections as well as using the HI stacking technique.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A159
- Title:
- 126 member galaxies of A780 radial velocities
- Short Name:
- J/A+A/658/A159
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Clusters of galaxies evolve and accrete mass, mostly from small galaxy systems. Our aim is to study the velocity field of the galaxy cluster Abell 780, which is known for the powerful radio source Hydra A at its center and where a spectacular X-ray tail associated with the galaxy LEDA 87445 has been discovered. Our analysis is based on the new spectroscopic data for hundreds of galaxies obtained with the Italian Telescopio Nazionale Galileo and the Very Large Telescope. We have constructed a redshift catalog of 623 galaxies and selected a sample of 126 cluster members. We analyze the internal structure of the cluster using a number of techniques. We estimate the mean redshift z=0.0545, the line-of-sight velocity dispersion {sigma}_v_~800km/s, and the dynamical mass M200~5.4x10^14^M_{sun}_. The global properties of Abell 780 are typical of relaxed clusters. On a smaller scale, we can detect the presence of a galaxy group associated with LEDA 87445 in projected phase space. The mean velocity and position of the center of the group agree well with the velocity and position of LEDA 87445. We estimate the following parameters of the collision. The group is characterized by a higher velocity relative to the main system. It is infalling at a rest frame velocity of V_rf_~+870km/s and lies at a projected distance D~1.1Mpc to the south, slightly southeast of the cluster center. The mass ratio between the group and the cluster is ~1:5. We also find evidence of an asymmetry in the velocity distribution of galaxies in the inner cluster region, which might be related to a small low-velocity group detected as a substructure at V_rf_~-750km/s. We conclude that A780, although dynamically relaxed at first sight, contains small substructures that may have some impact on the energetics of the core region.
- ID:
- ivo://CDS.VizieR/J/ApJ/727/14
- Title:
- Merging galaxy cluster A2255 in mid-IR
- Short Name:
- J/ApJ/727/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the mid-infrared (MIR) observation of a nearby galaxy cluster, A2255, by the AKARI space telescope. Using AKARI's continuous wavelength coverage between 3 and 24um and the wide field of view, we investigate the properties of cluster member galaxies to see how the infall of the galaxies, the cluster substructures, and the cluster-cluster merger influence their evolution. We show that the excess of MIR (~11um) flux is a good indicator for discriminating galaxies at different evolutionary stages and for dividing galaxies into three classes accordingly: strong MIR-excess (N3-S11>0.2) galaxies that include both unobscured and obscured star-forming galaxies; weak MIR-excess (-2.0<N3-S11<-1.2) galaxies that are quiescent, old (>5Gyr) galaxies where the MIR emission arises mainly from the circumstellar dust around AGB stars; and intermediate MIR-excess (-1.2<N3-S11<0.2) galaxies in between the two classes that are less than a few Gyr old past the prime star formation activity. With the MIR-excess diagnostics, we investigate how local and cluster-scale environments affect the individual galaxies. We derive the total star formation rate (SFR) and the specific SFR of A2255 using the strong MIR-excess galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJS/240/39
- Title:
- Merging galaxy cluster deep observations
- Short Name:
- J/ApJS/240/39
- Date:
- 18 Jan 2022 14:59:05
- Publisher:
- CDS
- Description:
- Multi-band photometric and multi-object spectroscopic surveys of merging galaxy clusters allow for the characterization of the distributions of constituent DM and galaxy populations, constraints on the dynamics of the merging subclusters, and an understanding of galaxy evolution of member galaxies. We present deep photometric observations from Subaru/SuprimeCam and a catalog of 4431 spectroscopic galaxies from Keck/DEIMOS observations of 29 merging galaxy clusters ranging in redshift from z=0.07 to 0.55. The ensemble is compiled based on the presence of radio relics, which highlight cluster-scale collisionless shocks in the intracluster medium. Together with the spectroscopic and photometric information, the velocities, timescales, and geometries of the respective merging events may be tightly constrained. In this preliminary analysis, the velocity distributions of 28 of the 29 clusters are shown to be well fit by single Gaussians. This indicates that radio-relic mergers largely occur transverse to the line of sight and/or near-apocenter. In this paper, we present our optical and spectroscopic surveys, preliminary results, and a discussion of the value of radio-relic mergers for developing accurate dynamical models of each system.
- ID:
- ivo://CDS.VizieR/J/A+A/602/A100
- Title:
- Merging groups and clusters from the SDSS data
- Short Name:
- J/A+A/602/A100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galaxy groups and clusters are the main tools to test cosmological models and to study the environmental effect of galaxy formation. This work aims to provide a catalogue of galaxy groups/clusters and potentially merging systems based on the SDSS main galaxy survey. We identify galaxy groups and clusters using the modified friends-of-friends (FoF) group finder that is designed specifically for flux-limited galaxy surveys. FoF group membership is refined by multimodality analysis to find subgroups and by using the group virial radius and escape velocity to expose unbound galaxies. We look for merging systems by comparing distances between group centres with group radii. The analysis results in a catalogue of 88 662 galaxy groups with at least two members. Among them are 6873 systems with at least 6 members which we consider as more reliable groups. We find 498 group mergers with up to six groups.
- ID:
- ivo://CDS.VizieR/J/MNRAS/458/226
- Title:
- MeSsI low-redshift merging cluster sample
- Short Name:
- J/MNRAS/458/226
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Merging galaxy systems provide observational evidence of the existence of dark matter and constraints on its properties. Therefore, statistically uniform samples of merging systems would be a powerful tool for several studies. In this paper, we present a new methodology for the identification of merging systems and the results of its application to galaxy redshift surveys. We use as a starting point a mock catalogue of galaxy systems, identified using friends-of-friends algorithms, that have experienced a major merger, as indicated by its merger tree. By applying machine learning techniques in this training sample, and using several features computed from the observable properties of galaxy members, it is possible to select galaxy groups that have a high probability of having experienced a major merger. Next, we apply a mixture of Gaussian techniques on galaxy members in order to reconstruct the properties of the haloes involved in such mergers. This methodology provides a highly reliable sample of merging systems with low contamination and precisely recovered properties. We apply our techniques to samples of galaxy systems obtained from the Sloan Digital Sky Survey Data Release 7, the Wide-Field Nearby Galaxy-Cluster Survey (WINGS) and the Hectospec Cluster Survey (HeCS). Our results recover previously known merging systems and provide several new candidates. We present their measured properties and discuss future analysis on current and forthcoming samples.
- ID:
- ivo://CDS.VizieR/J/A+A/546/A6
- Title:
- Metal abundances of galaxy clusters
- Short Name:
- J/A+A/546/A6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This work measures the evolution of the iron content in galaxy clusters by a rigorous analysis of the data of 130 clusters at 0.1<z<1.3. This task is made difficult by a) the low signal-to-noise ratio of abundance measurements and the upper limits, b) possible selection effects, c) boundaries in the parameter space, d) non-Gaussian errors, e) the intrinsic variety of the objects studied, and f) abundance systematics. We introduce a Bayesian model to address all these issues at the same time, thus allowing cross-talk (covariance).
- ID:
- ivo://CDS.VizieR/VIII/29A
- Title:
- 1400-MHz Survey of 1478 Abell Clusters of Galaxies
- Short Name:
- VIII/29A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains observations of Abell clusters of galaxies which were obtained with the Green Bank 91-m telescope at 1400 MHz with an angular resolution of 10'x11' (RAxDEC). This catalog extends the sample of clusters originally published in Owen (1974AJ.....79..427O). The primary goals of this survey were to observe all Abell (1958ApJS....3..211A, Cat. VII/4) clusters with m10 (magnitude of the tenth brightest galaxy in the cluster) less than or equal to 17.0 and declinations north of -19 degrees, to observe all clusters with richness>=3 regardless of m10, and to obtain observations of a representative sample of the rest of the catalog (m10>=17.0; richness<=2). The abelclus.dat file contains ALL 957 detected sources (also beyond 0.5 corrected Abell radii). It contains 525 sources within 0.5 corrected Abell radii, while the published table1.dat file contains 487 entries corresponding to 485 distinct sources (in 442 clusters). The catalog entries contains the flux density at 1400 MHz, the Abell cluster number, richness class, distance class, m10, redshift estimate (z), corrected Abell cluster radius, right ascension (B1950), declination (B1950), deconvolved major and minor source axis lengths, position angle, and distance of the source from the cluster center.
- ID:
- ivo://CDS.VizieR/J/A+AS/74/315
- Title:
- 327 MHz Survey of the A262 cluster region
- Short Name:
- J/A+AS/74/315
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains a survey at 327 MHz of the A262 cluster region. The survey was performed with the WSRT Telescope in the redundancy mode, and covers a circular region of 21 square degrees towards A262 (RA = 01h49m50s, decl = 35d54'20" -- B1950). The synthesized beam width is 56" x 93" (RA x DEC). 309 sources were detected, with a detection limit of 7 mJy (~5 sigma) at the field center. Nine of these galaxies have been identified with galaxies of the A262 cluster.
