- ID:
- ivo://CDS.VizieR/J/A+A/379/21
- Title:
- Radio-optically selected galaxy clusters I.
- Short Name:
- J/A+A/379/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The radiosource catalogs have been extracted from 31 NRAO VLA Sky Survey maps (NVSS, Condon et al., 1988AJ....115.1693C) over approximately 550 square degrees of sky in the region of the South Galactic Pole. File table1.dat contains the catalog of 13340 pointlike sources. For each source are given: Right Ascension and Declination, source name (if applicable), peak flux, flux rms from the fit, error on source position as estimated by the fitting algorithm, x and y pixel of the position where the peak has been detected on the map (starting position for the fit), control flags coming from the extraction algorithm, and name of the radio map where the source has been detected. The name is specified for (1) pointlike sources that are detected in a multiple system (name = DSnnnn or TSnnnn) (2) sources initially classified as components of a double system, which has been considered spurious on the basis of the distance between components (name = Cnnnn or DCnnnn). File table2.dat contains the catalog of 2662 double radiosources. For each source the following parameters are given both for the barycentre and the two components: Right Ascension and Declination, source name, peak flux, flux rms from the fit, error on source position as estimated by the fitting algorithm, distance between the components of the double system, x and y pixel of the position where the peak has been detected on the map (starting position for the fit), control flags coming from the extraction algorithm, and name of the radio map where the source has been detected.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/379/35
- Title:
- Radio-optically selected galaxy clusters. II.
- Short Name:
- J/A+A/379/35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File table1.dat contains data relative to spectroscopic and photometric observations of galaxies in 12 radio-optically selected candidate clusters. Observations have been acquired with the 3.6m ESO telescope, Chile. For each galaxy in the cluster, a sequential number, the magnitude in r-Gunn filter, the measured velocity, velocity rms, and notes to identify particular objects (emission galaxies, radiogalaxies and stars) are given.
- ID:
- ivo://CDS.VizieR/J/MNRAS/453/1201
- Title:
- Radio properties of brightest cluster galaxies
- Short Name:
- J/MNRAS/453/1201
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine the radio properties of the brightest cluster galaxies (BCGs) in a large sample of X-ray selected galaxy clusters comprising the Brightest Cluster Sample (BCS), the extended BCS and ROSAT-ESO Flux Limited X-ray cluster catalogues. We have multifrequency radio observations of the BCG using a variety of data from the Australia Telescope Compact Array, Jansky Very Large Array and Very Long Baseline Array telescopes. The radio spectral energy distributions of these objects are decomposed into a component attributed to on-going accretion by the active galactic nuclei (AGN) that we refer to as 'the core', and a more diffuse, ageing component we refer to as the 'non-core'. These BCGs are matched to previous studies to determine whether they exhibit emission lines (principally H{alpha}), indicative of the presence of a strong cooling cluster core. We consider how the radio properties of the BCGs vary with cluster environmental factors. Line emitting BCGs are shown to generally host more powerful radio sources, exhibiting the presence of a strong, distinguishable core component in about 60 per cent of cases. This core component more strongly correlates with the BCG's [OIII] 5007{AA} line emission. For BCGs in line emitting clusters, the X-ray cavity power correlates with both the extended and core radio emission, suggestive of steady fuelling of the AGN over bubble-rise time-scales in these clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/882/69
- Title:
- Radio relic merging galaxy cluster substructures
- Short Name:
- J/ApJ/882/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Golovich et al. (2019, J/ApJS/240/39) present an optical imaging and spectroscopic survey of 29 radio relic merging galaxy clusters. In this paper, we study this survey to identify substructure and quantify the dynamics of the mergers. Using a combined photometric and spectroscopic approach, we identify the minimum number of substructures in each system to describe the galaxy populations and estimate the line-of-sight velocity difference between likely merging subclusters. We find that the line-of-sight velocity components of the mergers are typically small compared with the maximum 3D relative velocity (usually <1000km/s and often consistent with zero). We also compare our systems to n-body simulation analogs and estimate the viewing angle of the clean mergers in our ensemble. We find that the median system's separation vector lies within 40{deg} (17{deg}) at a 90% (50%) confidence level. This suggests that the merger axes of these systems are generally in or near the plane of the sky, matching findings in magnetohydrodynamical simulations. In 28 of the 29 systems we identify substructures in the galaxy population aligned with the radio relic(s) and presumed associated merger-induced shock. From this ensemble, we identify eight systems to include in a "gold" sample that is prime for further observation, modeling, and simulation study. Additional papers will present weak-lensing mass maps and dynamical modeling for each merging system, ultimately leading to new insight into a wide range of astrophysical phenomena at some of the largest scales in the universe.
- ID:
- ivo://CDS.VizieR/J/ApJ/686/859
- Title:
- Radio sources at 0.327, 1.4, 4.5, 8.5GHz
- Short Name:
- J/ApJ/686/859
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the energetics and particle content of the lobes of 24 radio galaxies at the cores of cooling clusters. The radio lobes in these systems have created visible cavities in the surrounding hot, X-ray-emitting gas, which allow direct measurement of the mechanical jet power of radio sources over six decades of radio luminosity, independently of the radio properties themselves. We find that jet (cavity) power increases with radio synchrotron power approximately as P_jet_~L^{beta}^_radio_, where 0.35<={beta}<=0.70 depending on the bandpass of measurement and state of the source. Furthermore, we place limits on the magnetic field strengths and particle content of the radio lobes using a variety of X-ray constraints. We find that the lobe magnetic field strengths vary between a few to several tens of microgauss depending on the age and dynamical state of the lobes.
- ID:
- ivo://CDS.VizieR/J/AJ/118/625
- Title:
- Radio sources in Abell 2125 and 2645
- Short Name:
- J/AJ/118/625
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Abell clusters 2125 and 2645 have different radio source populations, despite being very similar in richness (Abell class 4) and redshift (0.25). The number density of radio sources in Abell 2125 is almost an order of magnitude more than that in Abell 2645, based on observations to the same optical and radio luminosities of the two clusters. About 30% of the radio sources in Abell 2125 shows signs of star formation, with the largest concentration of them in the southwest clump 2Mpc from the cluster center.
- ID:
- ivo://CDS.VizieR/J/ApJS/120/147
- Title:
- Radio sources in 14 Abell clusters
- Short Name:
- J/ApJS/120/147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a VLA C-configuration imaging survey of 14 rich Abell clusters. The observations were undertaken with the intent of characterizing the galaxy orbits within the cluster by combining galaxy redshifts with indicators of orbital shape. We present maps of the observed clusters, detailed maps of resolved sources detected in the survey, comparisons with optical images of the clusters, and tables of source parameters for all detected sources with measured flux values.
- ID:
- ivo://CDS.VizieR/J/AJ/134/897
- Title:
- Radio sources toward galaxy clusters at 30GHz
- Short Name:
- J/AJ/134/897
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extragalactic radio sources are a significant contaminant in cosmic microwave background and Sunyaev-Zel'dovich effect experiments. Deep interferometric observations with the BIMA and OVRO arrays are used to characterize the spatial, spectral, and flux distributions of radio sources toward massive galaxy clusters at 28.5GHz. We compute counts of millijansky source fluxes from 89 fields centered on known massive galaxy clusters and 8 noncluster fields.
- ID:
- ivo://CDS.VizieR/VIII/43
- Title:
- Radio survey of clusters of galaxies
- Short Name:
- VIII/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of Abell clusters at 11.1, 6.2, 6.3 and 2.8cm with the 100m Effelsberg telescope. The data were compiled by H.J. Andernach.
- ID:
- ivo://CDS.VizieR/J/MNRAS/391/297
- Title:
- Radio Survey of 7 X-ray Clusters of Galaxies
- Short Name:
- J/MNRAS/391/297
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Australia Telescope Compact Array (ATCA) has been used at 1.38 and 2.38GHz to survey seven southern Abell clusters of galaxies with high X-ray luminosities: A2746, A2837, A3126, A3216, A3230, A3827 and A3836. The clusters have also been surveyed at 0.843GHz with the Molonglo Observatory Synthesis Telescope (MOST). We have listed a complete 1.38-GHz sample of 149 radio sources within the Abell circles centred on their X-ray centroids. We compare their identification fractions, emitted 1.38-GHz and optical powers, radio spectral indices and radial variation in projected source density with those of the radio-selected samples of Slee et al. (1998AuJPh..51..971S). We compare our fractional radio luminosity function with that of the radio-selected samples of Ledlow and Owen (1996AJ....112....9L) and Slee et al. (1998AuJPh..51..971S). Three significant differences are noted between X-ray and radio-selected samples of clusters; (1) the X-ray sample has an excess of flat-spectrum radio sources; (2) the fractional radio luminosity function for the FR I sources in the X-ray selected sample is much steeper, implying that fewer of their cluster galaxies become hosts for the stronger FR I radio galaxies; (3) a complete absence of FR II radio galaxies in the X-ray selected sample. The average excess projected density of radio sources near our cluster centres is approx. 5 times the background source density.
