- ID:
- ivo://CDS.VizieR/J/MNRAS/460/2193
- Title:
- A3407 + A3408 radial velocities
- Short Name:
- J/MNRAS/460/2193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out a dynamical study of the galaxy cluster pair A3407 and A3408 based on a spectroscopic survey obtained with the 4 metre Blanco telescope at the Cerro Tololo Interamerican Observatory, plus 6dF data, and ROSAT All-Sky Survey. The sample consists of 122 member galaxies brighter than m_R_=20. Our main goal is to probe the galaxy dynamics in this field and verify if the sample constitutes a single galaxy system or corresponds to an ongoing merging process. Statistical tests were applied to clusters members showing that both the composite system A3407 + A3408 as well as each individual cluster have Gaussian velocity distribution. A velocity gradient of ~847+/-114km/s was identified around the principal axis of the projected distribution of galaxies, indicating that the global field may be rotating. Applying the kmm algorithm to the distribution of galaxies, we found that the solution with two clusters is better than the single unit solution at the 99 per cent cl. This is consistent with the X-ray distribution around this field, which shows no common X-ray halo involving A3407 and A3408. We also estimated virial masses and applied a two-body model to probe the dynamics of the pair. The more likely scenario is that in which the pair is gravitationally bound and probably experiences a collapse phase, with the cluster cores crossing in less than ~1h^-1^Gyr, a pre-merger scenario. The complex X-ray morphology, the gas temperature, and some signs of galaxy evolution in A3408 suggest a post-merger scenario, with cores having crossed each other ~1.65h^-1^Gyr ago, as an alternative solution.
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- ID:
- ivo://CDS.VizieR/J/A+AS/129/281
- Title:
- ABCG 85 velocities catalogue
- Short Name:
- J/A+AS/129/281
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of velocities for 551 galaxies (and give the coordinates of 39 stars misclassified as galaxies in our photometric plate catalogue) in a region covering about 100'x100' (0.94x0.94Mpc for an average redshift of 0.0555, assuming H_0_=50km/s/Mpc) in the direction of the rich cluster ABCG85. This catalogue includes previously published redshifts by Beers et al. (1991AJ....102.1581B) and Malumuth et al. (1992AJ....104..495M), together with our 367 new measurements. A total of 305 galaxies have velocities in the interval 13350-20000km/s, and will be considered as members of the cluster. ABCG 85 therefore becomes one of the clusters with the highest number of measured redshifts; its optical properties are being investigated in a companion paper.
- 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
- 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.
- ID:
- ivo://CDS.VizieR/J/A+AS/131/221
- Title:
- Abell 3733 radial velocities
- Short Name:
- J/A+AS/131/221
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cross-correlation and emission-line heliocentric radial velocities for 112 galaxies observed with the MEFOS and OPTOPUS spectrographs in the field of the galaxy cluster A3733. The last column lists the final radial velocities which result form a weighted average of the velocity data in the previous columns.
- ID:
- ivo://CDS.VizieR/J/MNRAS/296/599
- Title:
- A3558 complex redshifts
- Short Name:
- J/MNRAS/296/599
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Shapley Concentration is the richest supercluster of clusters in the nearby Universe, and its core is a remarkable complex formed by the ACO clusters A3558, A3562 and A3556, and by the two minor groups SC 1327-312 and SC 1329-314. This structure has been studied in various wavelength bands, revealing that it is probably dynamically very active. In this paper we present 174 new galaxy redshifts in this cluster complex, which are added to the sample of 540 already existing velocities. The spectroscopic observations were performed at the 3.6m ESO telescope at La Silla, equiped with the OPTOPUS multifibre spectrograph, on the nights 1993 February of 21-24.
- ID:
- ivo://CDS.VizieR/J/ApJS/153/223
- Title:
- ACS Virgo Cluster Survey. I.
- Short Name:
- J/ApJS/153/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Virgo Cluster is the dominant mass concentration in the Local Supercluster and the largest collection of elliptical and lenticular galaxies in the nearby universe. In this paper, we present an introduction to the ACS (Advanced Camera for Surveys) Virgo Cluster Survey: a program to image, in the F475W and F850LP bandpasses (~Sloan g and z), 100 early-type galaxies in the Virgo Cluster using the Advanced Camera for Surveys on the Hubble Space Telescope.
- ID:
- ivo://CDS.VizieR/J/ApJ/655/144
- Title:
- ACS Virgo Cluster Survey. XIII.
- Short Name:
- J/ApJ/655/144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ACS Virgo Cluster Survey consists of HST-ACS Advance Camera for Surveys) imaging for 100 early-type galaxies in the Virgo Cluster, observed in the F475W (~SDSS g) and F850LP (~SDSS z) filters. We derive distances for 84 of these galaxies using the method of surface brightness fluctuations (SBFs), present the SBF distance catalog, and use this database to examine the three-dimensional distribution of early-type galaxies in the Virgo Cluster. The SBF distance moduli have a mean (random) measurement error of 0.07mag (0.5Mpc), or roughly 3 times better than previous SBF measurements for Virgo Cluster galaxies. Five galaxies lie at a distance of d~23Mpc and are members of the W' cloud. The remaining 79 galaxies have a narrow distribution around our adopted distance of <d>=16.5+/-0.1 (random mean error) +/-1.1Mpc (systematic). The rms distance scatter of this sample is {sigma}(d)=0.6+/-0.1Mpc, with little or no dependence on morphological type or luminosity class (i.e., 0.7+/-0.1 and 0.5+/-0.1Mpc for the giants and dwarfs, respectively). The back-to-front depth of the cluster measured from our sample of early-type galaxies is 2.4+/-0.4Mpc (i.e., +/-2{sigma} of the intrinsic distance distribution). The M87 (cluster A) and M49 (cluster B) subclusters are found to lie at distances of 16.7+/-0.2 and 16.4+/-0.2Mpc, respectively. There may be a third subcluster associated with M86. A weak correlation between velocity and line-of-sight distance may be a faint echo of the cluster velocity distribution not having yet completely virialized. In three dimensions, Virgo's early-type galaxies appear to define a slightly triaxial distribution, with axis ratios of (1:0.7:0.5). The principal axis of the best-fit ellipsoid is inclined ~20{deg}-40{deg} from the line of sight, while the galaxies belonging to the W' cloud lie on an axis inclined by ~10{deg}-15{deg}.
- ID:
- ivo://CDS.VizieR/J/ApJ/850/207
- Title:
- Action dynamics of the Local Supercluster
- Short Name:
- J/ApJ/850/207
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The fully nonlinear gravitationally induced trajectories of a nearly complete set of galaxies, groups, and clusters in the Local Supercluster are constructed in a numerical action method model constrained by data from the CosmicFlows survey and various distance indicators. We add the gravity field due to inhomogeneities external to the sample sphere by making use of larger-scale peculiar flow measurements. Assignments of total masses were made to find the best overall set of mutual attractions, as determined by a goodness criterion based on present-day radial velocities, individually for the Virgo Cluster, M31, and the Milky Way (MW), and via a mass-to-light ratio relationship for other masses. The low median chi-square found indicates that the model fits the present-day velocity flow well, but a slightly high mean chi-square may indicate that some masses underwent complex orbits. The best fit, when setting the value of H_0_ to the CosmicFlows value of 75km/s/Mpc and the WMAP value for {Omega}_m_=0.244 consistent with that H_0_, occurs with the following parameters: {Omega}_orphan_=0.077+/-0.016, M/L_K_=40+/-2L_10_^0.15^M_{sun}_/L_{sun}_ (L_10_ is the K-band luminosity in units of 10^10^L_{sun}_), a Virgo mass of 6.3+/-0.8x10^14^M_{sun}_ (M/L_K_=113+/-15M_{sun}_/L_{sun}_), and a mass for the MW plus M31 of 5.15+/-0.35x10^12^M_{sun}_. The best constant mass-to-light ratio is M/L_K_=58+/-3M_{sun}_/L_{sun}_. The Virgocentric turnaround radius is 7.3+/-0.3Mpc. We explain several interesting trends in peculiar motions for various regions now that we can construct the 3D orbital histories.
- ID:
- ivo://CDS.VizieR/J/A+A/495/15
- Title:
- A959 galaxies r' magnitude and radial velocities
- Short Name:
- J/A+A/495/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The connection of cluster mergers with the presence of extended, diffuse radio sources in galaxy clusters is still being debated. We aim to obtain new insights into the internal dynamics of Abell 959, showing evidence of a diffuse radio source, analyzing velocities and positions of member galaxies. Our analysis is based on redshift data for 107 galaxies in the cluster field acquired at the Telescopio Nazionale Galileo. We also use photometric data from the Sloan Digital Sky Survey (Data Release 6). We combine galaxy velocities and positions to select 81 galaxies recognized as cluster members and determine global dynamical properties. We analyze the cluster searching for substructures by using the weighted gap analysis, the KMM method and the Dressler-Shectman statistics. We also study the 2D galaxy distribution in the field of the cluster. We compare our results with those from X-ray and gravitational lensing analyses.
