- ID:
- ivo://CDS.VizieR/J/MNRAS/430/3453
- Title:
- Radial velocities in A1914
- Short Name:
- J/MNRAS/430/3453
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyse the dynamical state of Abell 1914, a merging cluster hosting a radio halo, quite unusual for its structure. Our study considers spectroscopic data for 119 galaxies obtained with the Italian Telescopio Nazionale Galileo. We select 89 cluster members from spatial and velocity distributions. We also use photometry Canada-France-Hawaii Telescope archives. We compute the mean cluster redshift, <z>=0.168, and the velocity dispersion which shows a high value, {sigma}V=1210^+125^_-110_km/s. From the 2D analysis we find that Abell 1914 has a north-east (NE)-south-west (SW) elongated structure with two galaxy clumps, that mostly merge in the plane of the sky. Our best but very uncertain estimate of the velocity dispersion of the main system is {sigma}V, main ~1000km/s. We estimate a virial mass M_sys_=1.4-2.6x10^15^h^-1^_70_M_{sun}_ for the whole system. We study the merger through a simple two-body model and find that data are consistent with a bound, outgoing substructure observed just after the core crossing. By studying the 2D distribution of the red galaxies, photometrically selected, we show that Abell 1914 is contained in a rich large-scale structure, with two close companion galaxy systems, known to be at z~0.17. The system at SW supports the idea that the cluster is accreting groups from a filament aligned in the NE-SW direction, while that at NW suggests a second direction of the accretion (NW-SE). We conclude that Abell 1914 well fits among typical clusters with radio haloes. We argue that the unusual radio emission is connected to the complex cluster accretion and suggest that Abell 1914 resembles the well-known nearby merging cluster Abell 754 for its particular observed phenomenology.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/123/2261
- Title:
- Radial velocities in A2256
- Short Name:
- J/AJ/123/2261
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 236 new radial velocities of galaxies in the cluster A2256 measured with the WIYN Hydra Multi-Object Spectrograph. Combined with the previous work of Fabricant, Kent, & Kurtz (1989ApJ...336...77F), we have velocities for a total of 319 galaxies, of which 277 are cluster members. In addition to the new radial velocities, we present a 3x3 image mosaic in the R band of the central 19'x19' region of A2256, from which we obtained photometry for 861 galaxies. These data provide strong evidence for a merger event between two groups. In addition, we present evidence for the presence of a third group, on the outer reaches of the system, that is just now beginning to merge with the system.
- ID:
- ivo://CDS.VizieR/J/A+A/481/593
- Title:
- Radial velocities in A2163
- Short Name:
- J/A+A/481/593
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A2163 is among the richest and most distant Abell clusters, presenting outstanding properties in different wavelength domains. X-ray observations have revealed a distorted gas morphology and strong features have been detected in the temperature map, suggesting that merging processes are important in this cluster. However, the merging scenario is not yet well-defined. We have undertaken a complementary optical analysis, aiming to understand the dynamics of the system, to constrain the merging scenario and to test its effect on the properties of galaxies. We present a detailed optical analysis of A2163 based on new multicolor wide-field imaging and medium-to-high resolution spectroscopy of several hundred galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/449/461
- Title:
- Radial velocities in A2744
- Short Name:
- J/A+A/449/461
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed dynamical analysis of the rich galaxy cluster A2744, containing a powerful diffuse radio-halo. Our analysis is based on redshift data for 102 galaxies, part of them recovered from unexplored spectra in the ESO archive. We combine galaxy velocity and position information to select the cluster members and determine global dynamical properties of the cluster. We use a variety of statistical tests to detect possible substructures. We find that A2744 appears as a well isolated peak in the redshift space at <z>=0.306, which includes 85 galaxies recognized as cluster members. We compute the line-of-sight (LOS) velocity dispersion of galaxies, sigma_V_=1767_-99_^121^km/s, which is significantly larger than what is expected in the case of a relaxed cluster with an observed X-ray temperature of 8 keV. We find evidence that this cluster is far from dynamical equilibrium, as shown by the non Gaussianity of the velocity distribution, the presence of a velocity gradient and a significant substructure. Our analysis shows the presence of two galaxy-clumps of different mean LOS velocities DeltaV~4000km/s. We detect a main, low-velocity clump with sigma_V_~1200-1300km/s and a secondary, high-velocity clump with sigma_V_=500-800km/s and located in the S-SW cluster region. We estimate a cluster mass within 1Mpc of 1.4-2.4M_{sun}_, depending on the model adopted to describe the cluster dynamics. Our results suggest a merging scenario of two clumps with a mass ratio of 3:1 and a LOS impact velocity of DeltaV_rf_~3000km/s, likely observed just after the core passage. The merging is occuring roughly in the NS direction with the axis close to the LOS. This scenario agrees with that proposed on the basis of recent Chandra results in its general lines although pointing out for a somewhat more advanced merging phase. Our conclusions support the view of the connection between extended radio emission and energetic merging phenomena in galaxy clusters.
- ID:
- ivo://CDS.VizieR/J/AJ/118/1131
- Title:
- Radial velocities in A3565 and A3560
- Short Name:
- J/AJ/118/1131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report 102 new redshifts and magnitudes for a sample of galaxies to R_F_~15.5mag in a 2.17{deg}x2.17{deg} region centered on the galaxy IC 4296, the most luminous member of the A3565 Cluster. The sample of galaxies was defined from scans of an on-film copy of the ESO/Uppsala survey field 383 in the R band (IIIa-F emulsion plus GG 630 filter; hereafter ESO-LV) using the Observatsrio Nacional PDS 1010A microdensitometer.
- ID:
- ivo://CDS.VizieR/J/A+AS/114/565
- Title:
- Radial velocities in clusters of galaxies.
- Short Name:
- J/A+AS/114/565
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained 65 new redshifts in 4 Abell galaxy as well as 15 velocities of galaxies observed through the galactic plane, at ESO and OHP. Data on individual galaxies are presented, and the accuracy of the determined velocities are discussed as well as some properties of the clusters.
- ID:
- ivo://CDS.VizieR/J/A+A/515/A57
- Title:
- Radial velocities in clusters of galaxies. V.
- Short Name:
- J/A+A/515/A57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a part of our galaxy-cluster redshift survey, we present a set of 79 new velocities in the 4 clusters Abell 376, Abell 970, Abell 1356, and Abell 2244, obtained at Haute-Provence observatory. This set now completes our previous analyses, especially for the first two clusters. Data on individual galaxies are presented, and we discuss some cluster properties.
- ID:
- ivo://CDS.VizieR/J/MNRAS/383/445
- Title:
- Radial velocities in the Norma cluster (A3627)
- Short Name:
- J/MNRAS/383/445
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A detailed dynamical analysis of the nearby rich Norma cluster (ACO 3627) is presented. From radial velocities of 296 cluster members, we find a mean velocity of 4871+/-54km/s and a velocity dispersion of 925km/s. The mean velocity of the E/S0 population (4979+/-85km/s) is offset with respect to that of the S/Irr population (4812+/-70km/s) by {Delta}v=164km/s in the cluster rest frame. This offset increases towards the core of the cluster. The E/S0 population is free of any detectable substructure and appears relaxed. Its shape is clearly elongated with a position angle that is aligned along the dominant large-scale structures in this region, the so-called Norma wall. The central cD galaxy has a very large peculiar velocity of 561km/s which is most probably related to an ongoing merger at the core of the cluster.
- ID:
- ivo://CDS.VizieR/J/AJ/139/216
- Title:
- Radial velocities in UGC 842 and NGC 6034
- Short Name:
- J/AJ/139/216
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new insight on NGC 6034 and UGC 842, two groups of galaxies previously reported in the literature as being fossil groups. The study is based on optical photometry and spectroscopy obtained with the CTIO Blanco telescope and Sloan Digital Sky Survey archival data.
- ID:
- ivo://CDS.VizieR/J/A+A/469/861
- Title:
- Radial velocities of A115 galaxies
- Short Name:
- J/A+A/469/861
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a new spectroscopic and photometric survey of the hot, binary X-ray cluster A115 at z=0.193, containing a radio relic. Our analysis is based on new spectroscopic data obtained at the Telescopio Nazionale Galileo for 115 galaxies and on new photometric data obtained at the Isaac Newton Telescope in a large field. We combine galaxy velocity and position information to select 85 galaxies recognized as cluster members, determine global dynamical properties and detect substructures.
