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31. Abell 85 CCD observations
ID:
ivo://CDS.VizieR/J/MNRAS/211/637
Title:
Abell 85 CCD observations
Short Name:
J/MNRAS/211/637
Date:
21 Oct 2021
Publisher:
CDS
Description:
A CCD camera survey has been conducted of the X-ray emitting regions of a sample of clusters of galaxies. This sample includes at least one cluster from each of the classes in the new Forman-Jones classification scheme (Forman & Jones 1982ARA&A..20..547F). In this paper, the techniques used to obtain, reduce and analyse the data are presented, along with results for the cluster Abell 85. For the central X-ray emitting region of this cluster, a core radius of between 1.2 and 1.6Mpc is estimated from the galaxy radial number density distribution. The properties of the galaxies in the core of this cluster are significantly different from those of the galaxies in the outer regions of the area covered in the survey, in terms of luminosity function and colour distribution.
32. Abell Clusters
ID:
ivo://nasa.heasarc/abell
Title:
Abell Clusters
Short Name:
Abell
Date:
14 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
The ABELL database contains information from a catalog of clusters of galaxies, each having at least 30 members within the magnitude range m3 to m3+2 (m3 is the magnitude of the third brightest cluster member) and each with a nominal redshift less than 0.2. The database contains the revised Northern Abell catalog, the Southern Abell catalog, and the Supplementary Southern Abell catalog; the catalogs are published as tables 3, 4 and 5 of Abell, Corwin & Orowin (1989). This database table was created by J. Osborne of Leicester from the STADAT SCAR file abelb.dat. The original SCAR version was created by Diana Parsons on 12 March 1990. This is a service provided by NASA HEASARC .
33. Abell Clusters Measured Redshifts Catalog
ID:
ivo://nasa.heasarc/abellzcat
Title:
Abell Clusters Measured Redshifts Catalog
Short Name:
ABELLZCAT
Date:
14 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
The all-sky ACO (Abell, Corwin and Olowin 1989, ApJS, 70, 1) Catalog of 4073 rich clusters of galaxies and 1175 southern poor or distant S-clusters has been searched for published redshifts. Data for 1059 of them were found and classified into various quality classes, e.g. to reduce the problem of foreground contamination of redshifts. Taking the ACO selection criteria for redshifts, a total of 992 entries remain, 21 percent more than ACO. Redshifts for rich clusters are now virtually complete out to a redshift z of 0.05 in the north and of 0.04 in the south. In the north, the magnitude-redshift (m_10 - z) relation agrees with that of Kalinkov et al. (1985, Astr. Nachr., 306, 283). For the southern rich clusters, minor adjustments to the m_10 - z relation of ACO are suggested, while for the S-clusters the redshifts are about 30 percent lower than estimated. This table was created by the HEASARC in May 2010 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/165A">CDS Catalog VII/165A</a> file catalog.dat. This is a service provided by NASA HEASARC .
34. Abell clusters photometry
ID:
ivo://CDS.VizieR/J/ApJS/126/1
Title:
Abell clusters photometry
Short Name:
J/ApJS/126/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present CCD photometry of 209 southern Abell clusters selected according to Bautz-Morgan type I, III, and II. We have performed total photometry in the Gunn r bandpass, classified stars and galaxies, and obtained structural parameters for the images. To estimate the photometric and structural errors on the CCD images and the completeness limits of our photometry, we performed realistic simulations of stars and galaxies and ran our classification algorithms. Here, we present central galaxy counts and metric photometry of the brightest cluster members, for which we give accurate positions, and compare this photometry with values in the literature. A linear magnitude-redshift relation has been derived from the tenth-ranked galaxy in each cluster. Photometric redshifts have been estimated for 57 clusters. We provide either spectroscopic or photometric redshifts for all the clusters in our sample. Further analysis of these data will be presented in further publications.
35. 35 Abell clusters Tully-Fisher observations
ID:
ivo://CDS.VizieR/J/AJ/118/1468
Title:
35 Abell clusters Tully-Fisher observations
Short Name:
J/AJ/118/1468
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present Tully-Fisher observations for 35 rich Abell clusters of galaxies. Results from I-band photometry and optical rotation curve work constitute the bulk of this paper. This is the third such data installment of an all-sky survey of 52 clusters in the distance range ~50 to 200h^-1^Mpc. The complete data set provides the basis for determining an accurate Tully-Fisher template relation and for estimating the amplitude and direction of the local bulk flow on a 100h^-1^Mpc scale
36. Abell 576 galaxies magnitude and velocities
ID:
ivo://CDS.VizieR/J/ApJ/470/724
Title:
Abell 576 galaxies magnitude and velocities
Short Name:
J/ApJ/470/724
Date:
21 Oct 2021
Publisher:
CDS
Description:
We analyse the galaxy population and dynamics of the galaxy cluster A576; the observational constraints include 281 redshifts (230 new), R-band CCD galaxy photometry over a 2h^-1^Mpcx2h^-1^Mpc region centered on the cluster, an Einstein IPC X-ray image, and an Einstein MPC X-ray spectrum. We focus on an 86% complete magnitude-limited sample (R_23.5_<17) of 169 cluster galaxies. The cluster galaxies with emission lines in their spectra have a larger velocity dispersion and are significantly less clustered on this 2h^-1^Mpc scale than galaxies without emission lines. We show that excluding the emission-line galaxies from the cluster sample decreases the velocity dispersion by 18% and the virial mass estimate by a factor of 2. The central cluster region contains a non-emission galaxy population and an intracluster medium which is significantly cooler ({sigma}_core_=387^+250^_-105_km/s and T_X_=1.6-0.3/+0.4keV at 90% confidence) than the global populations ({sigma}=977^+124^_-96_km/s for the non-emission population and T_X_>4keV at 90% confidence). Because (1) the low-dispersion galaxy population is no more luminous than the global population and (2) the evidence for a cooling flow is weak, we suggest that the core of A576 may contain the remnants of a lower mass subcluster. We examine the cluster mass, baryon fraction, and luminosity function. The cluster virial mass varies significantly depending on the galaxy sample used. Consistency between the hydrostatic and virial estimators can be achieved if (1) the gas temperature at r~1h^-1^Mpc is T_X_~8keV (the best-fit value) and (2) several velocity outliers are excluded from the virial calculation. Although the best-fit Schechter function parameters and the ratio of galaxy to gas mass in A576 are typical of other clusters, the baryon fraction is relatively low. Using the consistent cluster binding mass, we show that the gas mass fraction is ~3h^-3/2^% and the baryon fraction is ~4%.
37. Abell 970 galaxies radial velocities
ID:
ivo://CDS.VizieR/J/A+A/377/428
Title:
Abell 970 galaxies radial velocities
Short Name:
J/A+A/377/428
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a dynamical analysis of the galaxy cluster Abell 970 based on a new set of radial velocities measured at ESO, Pic du Midi and Haute-Provence observatories. Our analysis indicates that this cluster has a substructure and is out of dynamical equilibrium. This conclusion is also supported by differences in the positions of the peaks of the surface density distribution and X-ray emission, as well as by the evidence of a large-scale velocity gradient in the cluster. We also found a discrepancy between the masses inferred with the virial theorem and those inferred with the X-ray emission, which is expected if the galaxies and the gas inside the cluster are not in hydrostatic equilibrium. Abell 970 has a modest cooling flow, as is expected if it is out of equilibrium. We propose that cooling flows may have an intermittent behaviour, with phases of massive cooling flows being followed by phases without significant cooling flows after the accretion of a galaxy group massive enough to disrupt the dynamical equilibrium in the centre of the clusters. A massive cooling flow will be established again, after a new equilibrium is achieved.
38. Abell 520 galaxies redshifts
ID:
ivo://CDS.VizieR/J/A+A/607/A131
Title:
Abell 520 galaxies redshifts
Short Name:
J/A+A/607/A131
Date:
21 Oct 2021
Publisher:
CDS
Description:
The mergers of galaxy clusters are the most energetic events in the universe after the Big Bang. An ever increasing fraction of local clusters exhibit signs of recent or past mergers. Our goal is to probe how these mergers affect the evolution and content of their member galaxies. We specifically aim to answer the following questions: Is the quenching of star formation in merging clusters enhanced when compared with relaxed clusters? Is the quenching accompanied by a (short lived) burst of star formation? We obtained optical spectroscopy of $>400$ galaxies in the field of the merging cluster Abell 520. We combine these observations with archival data to get a comprehensive picture of the state of star formation in the members of this merging cluster. Finally, we compare these observations with a control sample of 10 non-merging clusters at the same redshift from The Arizona Cluster Redshift Survey (ACReS). We split the member galaxies in passive, star forming or recently quenched depending on their spectra. The core of the merger shows a decreased fraction of star-forming galaxies compared to clusters in the non-merging sample. This region, dominated by passive galaxies, is extended along the axis of the merger. We find evidence of rapid quenching of the galaxies during the core passage with no signs of a star burst on the time scales of the merger. Additionally, we report the tentative discovery of an infalling group along the main filament feeding the merger, currently at ~2.5Mpc from the merger centre. This group contains a high fraction of star forming galaxies as well as ~2/3 of all the recently quenched galaxies in our survey.
39. Abell 3888 galaxies redshifts
ID:
ivo://CDS.VizieR/J/MNRAS/458/3083
Title:
Abell 3888 galaxies redshifts
Short Name:
J/MNRAS/458/3083
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper we present new AAOmega spectroscopy of 254 galaxies within a 30 arcmin radius around Abell 3888. We combine these data with the existing redshifts measured in a one degree radius around the cluster and performed a substructure analysis. We confirm 71 member galaxies within the core of A3888 and determine a new average redshift and velocity dispersion for the cluster of 0.1535+/-0.0009 and 1181+/-197km/s, respectively. The cluster is elongated along an East-West axis and we find the core is bimodal along this axis with two subgroups of 26 and 41 members detected. Our results suggest that A3888 is a merging system putting to rest the previous conjecture about the morphological status of the cluster derived from X-ray observations. In addition to the results on A3888 we also present six newly detected galaxy overdensities in the field, three of which we classify as new galaxy clusters.
40. Abell 1795 GMRT and Chandra maps
ID:
ivo://CDS.VizieR/J/A+A/618/A152
Title:
Abell 1795 GMRT and Chandra maps
Short Name:
J/A+A/618/A152
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper we analyze AGN activity signatures in the rich nearby galaxy cluster Abell 1795 aiming to confirm and characterize the long-term feedback history in the system. We combine radio observations at 610 and 235MHz from the Giant Metrewave Radio Telescope (GMRT) with 3.4Msec X-ray data from the Chandra Observatory. Extracting radial temperature profiles, as well as Xray and radio surface brightness profiles in three directions showing major morphological disturbances, we highlight the signatures of activity in the system. For the first time we observe radio emission corresponding to the NW X-ray depression, which provides evidence in favor of the classification of the depression as a cavity. We identify two other X-ray cavities situated NW and SW of the AGN. While the central radio emission corresponding to the inner cavities shows a flatter spectral index, the radio extensions associated with the farthest X-ray cavities consist of aged plasma. All observed signatures both in radio and X-ray are consistent with several consecutive episodes of AGN activity, which gave rise to the observed morphology NW and SW from the core. In the southern region, we confirm the cooling wake hypothesis for the origin of the long tail. The deep X-ray data also allows us to distinguish significant distortions in the tail's inner parts, which we attribute to the activity of the AGN.

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