- ID:
- ivo://CDS.VizieR/J/A+A/416/839
- Title:
- Radial velocities of A2219 galaxies
- Short Name:
- J/A+A/416/839
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the dynamical analysis of the rich, hot, and X-ray very luminous galaxy cluster A2219, containing a powerful diffuse radio-halo. Our analysis is based on new redshift data for 27 galaxies in the cluster region, measured from spectra obtained at the Telescopio Nazionale Galileo (TNG), with the addition of other 105 galaxies recovered from reduction of CFHT archive data in a cluster region of about 5-arcmin radius (about 0.8Mpc/h at the cluster distance) centered on the cD galaxy. The investigation of the dynamical status is also performed by using X-ray data stored in the Chandra archive. Further, valuable information comes from other bands - optical photometric, infrared, and radio data - which are analyzed and/or discussed, too. Our analyses support the view of the connection between extended radio emission and merging phenomena in galaxy clusters.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/130/957
- Title:
- Radial velocities of 6dF galaxies
- Short Name:
- J/AJ/130/957
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 546 optical redshifts obtained for galaxies in the region of the Horologium-Reticulum supercluster (HRS) using the 6{deg} field (6dF) multifiber spectrograph on the UK Schmidt Telescope at the Anglo-Australian Observatory. The HRS covers an area of more than 12{deg}x12{deg} on the sky centered at approximately RA=03h19m, DE=-50{deg}02'.
- ID:
- ivo://CDS.VizieR/J/A+A/455/45
- Title:
- Radial velocities of 93 galaxies in Abell 697
- Short Name:
- J/A+A/455/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We conduct an intensive study of the rich, X-ray luminous, and hot galaxy cluster Abell 697 (at z=0.282), likely containing a diffuse radio-emission, to determine its dynamical status. Our analysis is based on new spectroscopic data obtained at the TNG telescope for 93 galaxies and on new photometric data obtained at the INT telescope in a large field. We combine galaxy velocity and position information to select 68 cluster members (out to ~1.3h_70_^-1^Mpc from the cD galaxy), determine global dynamical properties, and detect possible substructures. The investigation of the dynamical status is also performed by using X-ray data stored in the Chandra archive.
- ID:
- ivo://CDS.VizieR/J/MNRAS/456/2829
- Title:
- Radial velocities of galaxies in A523 field
- Short Name:
- J/MNRAS/456/2829
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the structure of the galaxy cluster Abell 523 (A523) at z=0.104 using new spectroscopic data for 132 galaxies acquired at the Telescopio Nazionale Galileo, new photometric data from the Isaac Newton Telescope, and X-ray and radio data from the Chandra and Very Large Array archives. We estimate the velocity dispersion of the galaxy population, {sigma}_V_=949_-60_^+80^km/s, and the X-ray temperature of the hot intracluster medium, kT=5.3+/-0.3keV. We infer that A523 is a massive system: M_200_~7-9x10^14^M_{sun}_. The analysis of the optical data confirms the presence of two subclusters, 0.75Mpc apart, tracing the SSW-NNE direction and dominated by the two brightest cluster galaxies (BCG1 and BCG2). The X-ray surface brightness is strongly elongated towards the NNE direction, and its peak is clearly offset from both the brightest cluster galaxies (BCGs). We confirm the presence of a 1.3Mpc large radio halo, elongated in the ESE-WNW direction and perpendicular to the optical/X-ray elongation. We detect a significant radio/X-ray offset and radio polarization, two features which might be the result of a magnetic field energy spread on large spatial scales. A523 is found consistent with most scaling relations followed by clusters hosting radio haloes, but quite peculiar in the P_radio_-L_X_ relation: it is underluminous in the X-rays or overluminous in radio. A523 can be described as a binary head-on merger caught after a collision along the SSW-NNE direction. However, minor optical and radio features suggest a more complex cluster structure, with A523 forming at the crossing of two filaments along the SSW-NNE and ESE-WNW directions.
- ID:
- ivo://CDS.VizieR/J/A+A/383/823
- Title:
- Radial velocities of UCOs in Fornax
- Short Name:
- J/A+A/383/823
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The relation between the Ultra Compact Objects (hereafter UCOs) recently discovered in the Fornax cluster (Drinkwater et al., 2000PASA...17..227D; Hilker et al., 1999, Cat. <J/A+AS/134/75>) and the brightest globular clusters associated with the central galaxy NGC 1399 has been investigated. A spectroscopic survey on compact objects in the central region of the Fornax cluster was carried out with the 2.5 m du Pont telescope (LCO) at Las Campanas, in the three nights of 2000/12/30 to 2001/01/01. The magnitude limit was approx. V=21 mag, the spectral resolution approx. 4{AA}. UCOs and the bright NGC 1399 globular clusters with similar brightness were inspected. 12 GCs from the bright end of the globular cluster luminosity function have been identified as Fornax members. Eight are new members, four were known as members from before.
- ID:
- ivo://CDS.VizieR/J/ApJ/581/844
- Title:
- Radio and Infrared observations of EROs
- Short Name:
- J/ApJ/581/844
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a sensitive multiwavelength analysis of the properties of extremely red objects (EROs). Our analysis employs deep RIzJHK photometry of an 8.5'x8.5' region to select a sample of 68 EROs with (R-K)>=5.3 and brighter than K=20.5 (5{sigma}). We combine this photometric data set with an extremely deep 1.4GHz radio map of the field obtained from the VLA. This map reaches a 1{sigma} limiting flux density of 3.5{mu}Jy , making it the deepest 1.4GHz map taken, and is sensitive enough to detect an active galaxy with L1.4>~10^23^W/Hz at z>1.
- ID:
- ivo://CDS.VizieR/J/A+A/418/1
- Title:
- Radio continuum spectra in Virgo cluster region
- Short Name:
- J/A+A/418/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New radio continuum observations of galaxies in the Virgo cluster region at 4.85, 8.6, and 10.55GHz are presented. These observations are combined with existing measurements at 1.4 and 0.6GHz. The sample includes 81 galaxies where spectra with more than two frequencies could be derived. Galaxies that show a radio-FIR excess exhibit central activity (HII, LINER,AGN). The four Virgo galaxies with the highest absolute radio excess are found within 2 degrees of the center of the cluster. Galaxies showing flat radio spectra also host active centers. There is no clear trend between the spectral index and the galaxy's distance to the cluster center.
- ID:
- ivo://CDS.VizieR/J/A+AS/106/1
- Title:
- Radio data in Dumbbell galaxies
- Short Name:
- J/A+AS/106/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJS/134/355
- Title:
- Radio galaxies in 18 nearby Abell clusters
- Short Name:
- J/ApJS/134/355
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the use of the NRAO VLA Sky Survey (NVSS) to identify radio galaxies in 18 nearby Abell clusters. The listings extend from the cores of the clusters out to radii of 3Mpc (H_0_=75km/s/Mpc), which corresponds to 1.5 Abell radii and approximately 4 orders of magnitude in galaxy density. To create a truly useful catalog, we have collected optical spectra for nearly all of the galaxies lacking public velocity measurements. Consequently, we are able to discriminate between those radio galaxies seen in projection on the cluster and those that are in actuality cluster members. The resulting catalog consists of 329 cluster radio galaxies plus 138 galaxies deemed foreground or background objects, and new velocity measurements are reported for 273 of these radio galaxies. The motivation for the catalog is the study of galaxy evolution in the cluster environment. The radio luminosity function is a powerful tool in the identification of active galaxies, as it is dominated by star-forming galaxies at intermediate luminosities and active galactic nuclei (AGNs) at higher luminosities. The flux limit of the NVSS allows us to identify AGNs and star-forming galaxies down to star formation rates less than 1M_{sun}_/yr. This sensitivity, coupled with the all-sky nature of the NVSS, allows us to produce a catalog of considerable depth and breadth. In addition to these data, we report detected infrared fluxes and upper limits obtained from IRAS data. It is hoped that this database will prove useful in a number of potential studies of the effect of environment on galaxy evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/647/A50
- Title:
- Radio halos in mass selected clusters
- Short Name:
- J/A+A/647/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radio halos are synchrotron diffuse sources at the centre of a fraction of galaxy clusters. The study of large samples of clusters with adequate radio and X-ray data is necessary to investigate the origin of radio halos and their connection with the cluster dynamics and formation history. The aim of this paper is to compile a well-selected sample of galaxy clusters with deep radio observations to perform an unbiased statistical study of the properties of radio halos. We selected 75 clusters with M>=6x10^14^M_{sun}_ at z=0.08-0.33 from the Planck Sunyaev-Zel'dovich catalogue. Clusters without suitable radio data were observed with the Giant Metrewave Radio Telescope and/or the Jansky Very Large Array to complete the information about the possible presence of diffuse emission. We used archival Chandra X-ray data to derive information on the clusters' dynamical states. This observational campaign led to the detection of several cluster-scale diffuse radio sources and candidates that deserve future follow-up observations. Here we summarise their properties and add information resulting from our new observations. For the clusters where we did not detect any hint of diffuse emission, we derived new upper limits to their diffuse flux. We have built the largest mass-selected (>80% complete in mass) sample of galaxy clusters with deep radio observations available to date.
