- ID:
- ivo://CDS.VizieR/J/AJ/132/514
- Title:
- Galaxies of RX J1416.4+2315 cluster
- Short Name:
- J/AJ/132/514
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the properties of the fossil cluster RX J1416.4+2315 through g'- and i'-band imaging and spectroscopy of 25 member galaxies. The system is at a mean redshift of 0.137 and has a velocity dispersion of 584km/s. Superposed onto one quadrant of the cluster field is a group of five galaxies at a mean redshift of 0.131, which, if included as part of the cluster, increases the velocity dispersion to 846km/s. The central object of RX J1416.4+2315 is a normal elliptical galaxy with no cD envelope.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/138/873
- Title:
- Galaxies with H{alpha} emission in A2151
- Short Name:
- J/AJ/138/873
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the first results of an H{alpha} imaging survey of galaxies in the central regions of the A2151 cluster. A total of 50 sources were detected in H{alpha}, from which 41 were classified as secure members of the cluster and 2 as likely members based on spectroscopic and photometric redshift considerations. The remaining seven galaxies were classified as background contaminants and thus excluded from our study on the H{alpha} properties of the cluster.
- ID:
- ivo://CDS.VizieR/J/ApJ/820/98
- Title:
- Galaxy candidates in the Hubble Frontier Fields
- Short Name:
- J/ApJ/820/98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present the results of our search for and study of z>~6 galaxy candidates behind the third Frontier Fields (FFs) cluster, MACS J0717.5+3745, and its parallel field, combining data from Hubble and Spitzer. We select 39 candidates using the Lyman break technique, for which the clear non-detection in optical make the extreme mid-z interlopers hypothesis unlikely. We also take benefit from z>~6 samples selected using the previous FF data sets of Abell 2744 and MACS 0416 to improve the constraints on the properties of very high redshift objects. We compute the redshift and the physical properties such emission lines properties, star formation rate, reddening, and stellar mass for all FF objects from their spectral energy distribution using templates including nebular emission lines. We study the relationship between several physical properties and confirm the trend already observed in previous surveys for evolution of star formation rate with galaxy mass and between the size and the UV luminosity of our candidates. The analysis of the evolution of the UV luminosity function with redshift seems more compatible with an evolution of density. Moreover, no robust z>=8.5 object is selected behind the cluster field and few z~9 candidates have been selected in the two previous data sets from this legacy survey, suggesting a strong evolution in the number density of galaxies between z~8 and 9. Thanks to the use of the lensing cluster, we study the evolution of the star formation rate density produced by galaxies with L>0.03 L_{star}_, and confirm the strong decrease observed between z~8 and 9.
- ID:
- ivo://CDS.VizieR/J/ApJS/246/2
- Title:
- Galaxy cluster cat. from SDSS-DR13 (GalWCat19)
- Short Name:
- J/ApJS/246/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Utilizing the SDSS-DR13 spectroscopic data set, we create a new publicly available catalog of 1800 galaxy clusters (GalWeight cluster catalog, GalWCat19) and a corresponding catalog of 34,471 identified member galaxies. The clusters are identified from overdensities in redshift phase space. The GalWeight technique introduced by Abdullah+ (2018ApJ...861...22A) is then applied to identify cluster members. The completeness of the cluster catalog (GalWCat19) and the procedure followed to determine cluster mass are tested on the Bolshoi N-body simulations. The 1800 GalWCat19 clusters range in redshift between 0.01 and 0.2 and have masses in the range of (0.4-14)x10^14^h^-1^M_{sun}_. The cluster catalog provides a large number of cluster parameters, including sky position, redshift, membership, velocity dispersion, and mass at overdensities {Delta}=500, 200, 100, and 5.5. The 34471 member galaxies are identified within the radius at which the density is 200 times the critical density of the universe. The galaxy catalog provides the coordinates of each galaxy and the ID of the cluster that the galaxy belongs to. The cluster velocity dispersion scales with mass as log({sigma}_200_)=log(946+/-52km/s)+ (0.349+/-0.142)log[h(z)M_200_/10^1 5^M_{sun}], with a scatter of {delta}log{sigma}=0.06+/-0.04.
- ID:
- ivo://CDS.VizieR/J/MNRAS/455/892
- Title:
- Galaxy cluster concentration-mass relation
- Short Name:
- J/MNRAS/455/892
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Scaling relations of clusters have made them particularly important cosmological probes of structure formation. In this work, we present a comprehensive study of the relation between two profile observables, concentration (cvir) and mass (Mvir). We have collected the largest known sample of measurements from the literature which make use of one or more of the following reconstruction techniques: weak gravitational lensing (WL), strong gravitational lensing (SL), weak+strong lensing (WL+SL), the caustic method (CM), line-of-sight velocity dispersion (LOSVD), and X-ray. We find that the concentration-mass (c-M) relation is highly variable depending upon the reconstruction technique used. We also find concentrations derived from dark matter-only simulations (at approximately Mvir~10^14^M_{sun}_) to be inconsistent with the WL and WL+SL relations at the 1{sigma} level, even after the projection of triaxial haloes is taken into account. However, to fully determine consistency between simulations and observations, a volume-limited sample of clusters is required, as selection effects become increasingly more important in answering this. Interestingly, we also find evidence for a steeper WL+SL relation as compared to WL alone, a result which could perhaps be caused by the varying shape of cluster isodensities, though most likely reflects differences in selection effects caused by these two techniques. Lastly, we compare concentration and mass measurements of individual clusters made using more than one technique, highlighting the magnitude of the potential bias which could exist in such observational samples.
- ID:
- ivo://CDS.VizieR/J/AJ/141/88
- Title:
- Galaxy cluster environments of radio sources
- Short Name:
- J/AJ/141/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Sloan Digital Sky Survey (SDSS) and the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) catalogs, we examined the optical environments around double-lobed radio sources. Previous studies have shown that multi-component radio sources exhibiting some degree of bending between components are likely to be found in galaxy clusters. Often this radio emission is associated with a cD-type galaxy at the center of a cluster. We cross-correlated the SDSS and FIRST catalogs and measured the richness of the cluster environments surrounding both bent and straight multi-component radio sources. This led to the discovery and classification of a large number of galaxy clusters out to a redshift of z~0.5.
- ID:
- ivo://CDS.VizieR/J/MNRAS/450/2261
- Title:
- Galaxy cluster outskirts probed by Chandra
- Short Name:
- J/MNRAS/450/2261
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied the physical properties of the intracluster medium (ICM) in the virialization region of a sample of 320 clusters (0.056<z<1.24, kT>~3keV) in the Chandra archive. With the emission measure profiles from this large sample, the typical gas density, gas slope and gas fraction can be constrained out to and beyond R200. We observe a steepening of the density profiles beyond R500 with {beta}~0.68 at R500 and {beta}~1 at R200 and beyond. By tracking the direction of the cosmic filaments approximately with the ICM eccentricity, we report that galaxy clusters deviate from spherical symmetry, with only small differences between relaxed and disturbed systems. We also did not find evolution of the gas density with redshift, confirming its self-similar evolution. The value of the baryon fraction reaches the cosmic value at R200; however, systematics due to non-thermal pressure support and clumpiness might enhance the measured gas fraction, leading to an actual deficit of the baryon budget with respect to the primordial value. This study has important implications for understanding the ICM physics in the outskirts.
- ID:
- ivo://CDS.VizieR/J/ApJ/774/40
- Title:
- Galaxy clusters aligned with quasars. III.
- Short Name:
- J/ApJ/774/40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Gemini/GMOS-S multi-object spectroscopy of 31 galaxy cluster candidates at redshifts between 0.2 and 1.0 and centered on QSO sight lines taken from Lopez et al. (Paper I, J/ApJ/679/1144). The targets were selected based on the presence of an intervening MgII absorption system at a similar redshift to that of a galaxy cluster candidate lying at a projected distance <2h_71_^-1^Mpc from the QSO sight line (a "photometric hit"). The absorption systems span rest-frame equivalent widths between 0.015 and 2.028{AA}. The general population of our confirmed absorbing galaxies have luminosities L_B_~L_B_^*^ and mean rest-frame colors (R_c_-z') typical of S_cd_ galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/611/A94
- Title:
- 6 galaxy clusters ATCA 2.1GHz images
- Short Name:
- J/A+A/611/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A fraction of galaxy clusters host diffuse radio sources whose origins are investigated through multi-wavelength studies of cluster samples. We investigate the presence of diffuse radio emission in a sample of seven galaxy clusters in the largely unexplored intermediate redshift range (0.3<z<0.44). In search of diffuse emission, deep radio imaging of the clusters are presented from wide band (1.1-3.1GHz), full resolution (~5-arcsec) observations with the Australia Telescope Compact Array (ATCA). The visibilities were also imaged at lower resolution after point source modelling and subtraction and after a taper was applied to achieve better sensitivity to low surface brightness diffuse radio emission. In case of non-detection of diffuse sources, we set upper limits for the radio power of injected diffuse radio sources in the field of our observations. Furthermore, we discuss the dynamical state of the observed clusters based on an X-ray morphological analysis with XMM-Newton. We detect a giant radio halo in PSZ2 G284.97-23.69 (z=0.39) and a possible diffuse source in the nearly relaxed cluster PSZ2 G262.73-40.92 (z=0.421). Our sample contains three highly disturbed massive clusters without clear traces of diffuse emission at the observed frequencies. We were able to inject modelled radio halos with low values of total flux density to set upper detection limits; however, with our high-frequency observations we cannot exclude the presence of RH in these systems because of the sensitivity of our observations in combination with the high z of the observed clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/439/1796
- Title:
- Galaxy clusters at z=0.23 and 0.45 X-ray emission
- Short Name:
- J/MNRAS/439/1796
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The thermal, chemical, and kinematic properties of the potentially multiphase circum/intergalactic medium at the virial radii of galaxy clusters remain largely uncertain. We present an X-ray study of Abell 2246 and GMBCG J255.34805+64.23661 (z=0.23 and 0.45), two foreground clusters of the UV-bright QSO HS 1700+6416, based on 240ks Chandra/Advanced CCD Imaging Spectrometer observations. We detect enhanced diffuse X-ray emission to the projected distances beyond r_200_ radii of these two clusters. The large-scale X-ray emission is consistent with being azimuthally symmetric at the projected radii of the QSO (0.36 and 0.8 times the radii of the two clusters). Assuming a spherical symmetry, we obtain the de-projected temperature and density profiles of the X-ray-emitting gas. Excluding the cool cores that are detected, we find that the mean temperature of the hot gas is ~4.0keV for Abell 2246 and 5.5keV for GMBCG J255.34805+64.23661, although there are indications for temperature drop at large radii. From these results, we can estimate the density and pressure distributions of the hot gas along the QSO sightline. We further infer the radial entropy profile of Abell 2246 and compare it with the one expected from purely gravitational hierarchical structure formation. This comparison shows that the intracluster medium in the outer region of the clusters is likely in a clumpy and multiphased state. These results, together with the upcoming Hubble Space Telescope/Cosmic Origins Spectrograph observations of the QSO sightline, will enable a comprehensive investigation of the multiphase medium associated with the clusters.
