- ID:
- ivo://CDS.VizieR/J/A+A/622/A22
- Title:
- Abell 1914 multiwavelength radio images
- Short Name:
- J/A+A/622/A22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A number of radio observations have revealed the presence of large synchrotron-emitting sources associated with the intra-cluster medium. There is strong observational evidence that the emitting particles have been (re-)accelerated by shocks and turbulence generated during merger events. The particles that are accelerated are thought to have higher initial energies than those in the thermal pool but the origin of such mildly relativistic particles remains uncertain and needs to be further investigated. The galaxy cluster Abell 1914 is a massive galaxy cluster in which X-ray observations show clear evidence of merging activity. We carried out radio observations of this cluster with the LOw Frequency ARay (LOFAR) at 150MHz and the Giant Metrewave Radio Telescope (GMRT) at 610MHz. We also analysed Very Large Array (VLA) 1.4GHz data, archival GMRT 325MHz data, CFHT weak lensing data and Chandra observations. Our analysis shows that the ultra-steep spectrum source (4C38.39; {alpha}<~-2), previously thought to be part of a radio halo, is a distinct source with properties that are consistent with revived fossil plasma sources. Finally, we detect some diffuse emission to the west of the source 4C38.39 that could belong to a radio halo.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/469/3946
- Title:
- Abell 370 MUSE redshifts
- Short Name:
- J/MNRAS/469/3946
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a strong lensing analysis on the massive cluster Abell 370 (A370; z=0.375), using a combination of deep multiband Hubble Space Telescope (HST) imaging and Multi-Unit Spectroscopic Explorer (MUSE) spectroscopy. From only 2 h of the MUSE data, we are able to measure 120 redshifts in the southern BCG area, including several multiply imaged lens systems. In total, we increase the number of multiply imaged systems with a secure redshift from 4 to 15, nine of which are newly discovered. Of these, eight are located at z>3, greatly extending the redshift range of spectroscopically confirmed systems over previous work. Using these systems as constraints, we update a parametric lens model of A370, probing the mass distribution from cluster to galaxy scales. Overall, we find that a model with only two cluster-scale dark matter haloes (one for each BCG) does a poor job of fitting these new image constraints. Instead, two additional mass clumps - a central 'bar' of mass located between the BCGs, and another clump located within a 'crown' of galaxies in the northern part of the cluster field - provide significant improvements to the fit. Additional physical evidence suggests these clumps are indeed real features of the system, but with relatively few image constraints in the crown region, this claim is difficult to evaluate from a modelling perspective. Additional MUSE observations of A370 covering the entire strong-lensing region will greatly help these efforts, further improving our understanding of this intriguing cluster.
- ID:
- ivo://CDS.VizieR/J/A+AS/139/559
- Title:
- Abell 496 photometric catalogue
- Short Name:
- J/A+AS/139/559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Two catalogues of galaxies in the direction of the cluster Abell 496 are presented. The first one includes 3,879 galaxies located in a region roughly +/-1.3 degree from the cluster centre ; it has been obtained by scanning part of a Schmidt photographic plate taken in the Bj band. Positions are very accurate but magnitudes are not. A second catalogue gives a list of galaxies with CCD magnitudes in the V (239 galaxies) and R (610 galaxies) bands for a much smaller region in the centre of the cluster.
- 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/A+A/649/A37
- Title:
- Abell 1775 radio images
- Short Name:
- J/A+A/649/A37
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Thermal gas in the center of galaxy clusters can show substantial motions that generate surface brightness and temperature discontinuities known as cold fronts. The motions may be triggered by minor or o-axis mergers that preserve the cool-core of the system. The dynamics of the thermal gas can also generate radio emission from the intra-cluster medium (ICM) and impact the evolution of clusters radio sources. We study the central region of Abell 1775, a system in an ambiguous dynamical state at z=0.072 which is known to host an extended head-tail radio galaxy, with the aim of investigating the connection between thermal and non-thermal components in its center. We made use of a deep (100ks) Chandra observation accompanied by LOFAR 144MHz, GMRT 235MHz and 610MHz, and VLA 1.4GHz radio data. We find a spiral-like pattern in the X-ray surface brightness that is mirrored in the temperature and pseudo-entropy maps. Additionally, we characterize an arc-shaped cold front in the ICM. We interpret these features in the context of a slingshot gas tail scenario. The structure of the head-tail radio galaxy "breaks" at the position of the cold front, showing an extension that is detected only at low frequencies, likely due to its steep and curved spectrum. We speculate that particle re-acceleration is occurring in the outer region of this tail, that in total covers a projected size of 800kpc. We also report the discovery of revived fossil plasma with ultra-steep spectrum radio emission in the cluster core together with a central diffuse radio source that is bounded by the arc-shaped cold front. The results reported in this work demonstrate the interplay between thermal and non-thermal components in the cluster center and the presence of ongoing particle re-acceleration in the ICM on different scales.
- ID:
- ivo://CDS.VizieR/J/A+A/643/A172
- Title:
- Abell 2626 radio source LOFAR image at 144MHz
- Short Name:
- J/A+A/643/A172
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new LOFAR data of the galaxy cluster Abell 2626. Weproduced a new, resolved spectral index map of the source with a resolution of 7" and we studied the spatial correlation of radio and X-ray emission to investigate the interplay between thermal and nonthermal plasma. The new LOFAR data changed our view of the Kite because we discovered two steep-spectrum ({alpha}<-1.5) plumes of emission connected to the arcs. On the basis of our results, we propose that the Kite was originally an X-shaped radio galaxy whose fossil radio plasma, after the end of the activity of the central active galactic nucleus, has been compressed as a consequence of motions of the thermal plasma encompassing the galaxy. The interplay between the compression and advection of the fossil plasma, with the restarting of the nuclear activity of the central galaxy,could have enhanced the radio emission of the fossil plasma producing the arcs of the Kite. We also present the first, low-frequency observation of a jellyfish galaxy in the same field, in which we detect extended, low-frequency emission without a counterpart at higher frequencies.
- ID:
- ivo://CDS.VizieR/J/AJ/120/2338
- Title:
- Abell 576 redshifts
- Short Name:
- J/AJ/120/2338
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe observations of the nearby (cz=11487km/s) cluster of galaxies Abell 576 beyond the virial radius and into the infall region where galaxies are on their first or second pass through the cluster. Using 1057 redshifts, we use the infall pattern in redshift space to determine the mass profile of A576 to a radius of ~4h^-1^Mpc.
- ID:
- ivo://CDS.VizieR/J/MNRAS/477/648
- Title:
- Abell S1063 and MACS J1149.5+2223 photometry
- Short Name:
- J/MNRAS/477/648
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyse the Kormendy relations (KRs) of the two Frontier Fields clusters, Abell S1063, at z=0.348, and MACS J1149.5+2223, at z=0.542, exploiting very deep Hubble Space Telescope photometry and Very Large Telescope (VLT)/Multi Unit Spectroscopic Explorer (MUSE) integral field spectroscopy. With this novel data set, we are able to investigate how the KR parameters depend on the cluster galaxy sample selection and how this affects studies of galaxy evolution based on the KR. We define and compare four different galaxy samples according to (a) Sersic indices: early-type ('ETG'), (b) visual inspection: 'ellipticals', (c) colours: 'red', (d) spectral properties: 'passive'. The classification is performed for a complete sample of galaxies with m_F814W_<=22.5-ABmag (M_*_>=10^10.0^M_{sun}_). To derive robust galaxy structural parameters, we use two methods: (1) an iterative estimate of structural parameters using images of increasing size, in order to deal with closely separated galaxies and (2) different background estimations, to deal with the intracluster light contamination. The comparison between the KRs obtained from the different samples suggests that the sample selection could affect the estimate of the best-fitting KR parameters. The KR built with ETGs is fully consistent with the one obtained for ellipticals and passive. On the other hand, the KR slope built on the red sample is only marginally consistent with those obtained with the other samples. We also release the photometric catalogue with structural parameters for the galaxies included in the present analysis.
- ID:
- ivo://CDS.VizieR/J/A+A/602/A20
- Title:
- Abell 315 spectroscopic dataset
- Short Name:
- J/A+A/602/A20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Determination of cluster masses is a fundamental tool for cosmology. Comparing mass estimates obtained by different probes allows to understand possible systematic uncertainties. Aims. The cluster Abell 315 is an interesting test case, since it has been claimed to be underluminous in X-ray for its mass (determined via kinematics and weak lensing). We have undertaken new spectroscopic observations with the aim of improving the cluster mass estimate, using the distribution of galaxies in projected phase space. We identified cluster members in our new spectroscopic sample. We estimated the cluster mass from the projected phase-space distribution of cluster members using the MAMPOSSt method. In doing this estimate we took into account the presence of substructures that we were able to identify. We identify several cluster substructures. The main two have an overlapping spatial distribution, suggesting a (past or ongoing) collision along the line-of-sight. After accounting for the presence of substructures, the mass estimate of Abell 315 from 14 kinematics is reduced by a factor 4, down to M_200_=0.8_-0.4_^+0.6^10+14M_{sun}_. We also find evidence that the cluster mass concentration is unusually low, c_200_=r_200_/r_-2_<1. Using our new estimate of c200 we revise the weak lensing mass estimate down to M_200_=1.8_-0.9_^+1.7^10+14M_{sun}_. Our new mass estimates are in agreement with that derived from the cluster X-ray luminosity via a scaling relation, M_200_=0.9+/-0.2*10^14^M_{sun}_. Abell 315 no longer belongs to the class of X-ray underluminous clusters. Its mass estimate was inflated by the presence of an undetected subcluster in collision with the main cluster. Whether the presence of undetected line-of-sight structures can be a general explanation for all X-ray underluminous clusters remains to be explored using a statistically significant sample.
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/1437
- Title:
- Abell 2744 strong-lensing analysis
- Short Name:
- J/MNRAS/452/1437
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a high-precision mass model of galaxy cluster Abell 2744, based on a strong gravitational-lensing analysis of the Hubble Space Telescope Frontier Fields (HFF) imaging data, which now include both Advanced Camera for Surveys and Wide Field Camera 3 observations to the final depth. Taking advantage of the unprecedented depth of the visible and near-infrared data, we identify 34 new multiply imaged galaxies, bringing the total to 61, comprising 181 individual lensed images. In the process, we correct previous erroneous identifications and positions of multiple systems in the northern part of the cluster core. With the lenstool software and the new sets of multiple images, we model the cluster using two cluster-scale dark matter haloes plus galaxy-scale haloes for the cluster members. Our best-fitting model predicts image positions with an rms error of 0.79 arcsec, which constitutes an improvement by almost a factor of 2 over previous parametric models of this cluster. We measure the total projected mass inside a 200kpc aperture as (2.162+/-0.005)x10^14^M_{sun}_, thus reaching 1 percent level precision for the second time, following the recent HFF measurement of MACSJ0416.1-2403. Importantly, the higher quality of the mass model translates into an overall improvement by a factor of 4 of the derived magnification factor. Together with our previous HFF gravitational lensing analysis, this work demonstrates that the HFF data enables high-precision mass measurements for massive galaxy clusters and the derivation of robust magnification maps to probe the early Universe.
