- ID:
- ivo://CDS.VizieR/J/MNRAS/452/3304
- Title:
- AC114 galaxy cluster dynamical analysis
- Short Name:
- J/MNRAS/452/3304
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a dynamical analysis of the galaxy cluster AC114 based on a catalogue of 524 velocities. Of these, 169 (32 percent) are newly obtained at European Southern Observatory (Chile) with the Very Large Telescope and the VIsible MultiObject spectrograph. Data on individual galaxies are presented and the accuracy of the measured velocities is discussed. Dynamical properties of the cluster are derived. We obtain an improved mean redshift value z=0.31665+/-0.0008 and velocity dispersion {sigma}=1893^+73^_-82_km/s. A large velocity dispersion within the core radius and the shape of the infall pattern suggests that this part of the cluster is in a radial phase of relaxation with a very elongated radial filament spanning 12000km/s. A radial foreground structure is detected within the central 0.5h^-1^Mpc radius, recognizable as a redshift group at the same central redshift value. We analyse the colour distribution for this archetype Butcher-Oemler galaxy cluster and identify the separate red and blue galaxy sequences. The latter subset contains 44 percent of confirmed members of the cluster, reaching magnitudes as faint as R_f_=21.1 (1.0mag fainter than previous studies). We derive a mass M_200_=(4.3+/-0.7)x10^15^M_{sun}_h^-1^. In a subsequent paper, we will utilize the spectral data presented here to explore the mass-metallicity relation for this intermediate redshift cluster.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/477/55
- Title:
- ACO 1825 and AC 114 EROs photometry
- Short Name:
- J/A+A/477/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the properties and nature of extremely red galaxies (ERO, R-K>=5.6) found behind two lensing clusters and compare them with other known galaxy populations. New HST/ACS, Spitzer (IRAC and MIPS), and Chandra/ACIS observations of the two lensing clusters Abell 1835 and AC 114 (ACCG 114) have been obtained, combined with our earlier optical and near-IR observations and used to study EROs in these deep fields.
- ID:
- ivo://CDS.VizieR/J/A+A/407/791
- Title:
- ACO 370, 2218 and 2390 fluxes at 7 and 15um
- Short Name:
- J/A+A/407/791
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- ESA's Infrared Space Observatory (ISO) was used to perform a deep survey with ISOCAM through three massive gravitationally lensing clusters of galaxies. The total area surveyed depends on source flux, with nearly seventy square arcminutes covered for the brighter flux levels in maps centred on the three clusters Abell 370, Abell 2218 and Abell 2390. We present maps and photometry at 6.7um (hereafter 7um) and 14.3um (hereafter 15um), showing a total of 145 mid-infrared sources and the associated source counts.
- ID:
- ivo://CDS.VizieR/J/A+A/401/471
- Title:
- A1367, Coma and Virgo r' photometry
- Short Name:
- J/A+A/401/471
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical spectroscopy of 93 galaxies, 60 projected in the direction of Abell 1367, 21 onto the Coma cluster and 12 on Virgo, is reported. The targets were selected because they were detected in previous H{alpha}, UV or r' surveys. The present observations bring to 100% the redshift completeness of H{alpha} selected galaxies in the Coma region and to 75% in Abell 1367. All observed galaxies except one show H{alpha} emission and belong to the clusters. This confirms previous determinations of the H{alpha} luminosity function of the two clusters that were based on the assumption that all H{alpha} detected galaxies were cluster members. Using the newly obtained data we re-determine the UV luminosity function of Coma and we compute for the first time the UV luminosity function of A1367.
- ID:
- ivo://CDS.VizieR/J/MNRAS/296/599
- Title:
- A3558 complex redshifts
- Short Name:
- J/MNRAS/296/599
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Shapley Concentration is the richest supercluster of clusters in the nearby Universe, and its core is a remarkable complex formed by the ACO clusters A3558, A3562 and A3556, and by the two minor groups SC 1327-312 and SC 1329-314. This structure has been studied in various wavelength bands, revealing that it is probably dynamically very active. In this paper we present 174 new galaxy redshifts in this cluster complex, which are added to the sample of 540 already existing velocities. The spectroscopic observations were performed at the 3.6m ESO telescope at La Silla, equiped with the OPTOPUS multifibre spectrograph, on the nights 1993 February of 21-24.
- ID:
- ivo://CDS.VizieR/J/ApJS/169/213
- Title:
- ACS Fornax Cluster Survey. I.
- Short Name:
- J/ApJS/169/213
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Fornax Cluster is a conspicuous cluster of galaxies in the southern hemisphere and the second largest collection of early-type galaxies within 20Mpc after the Virgo Cluster. In this paper, we present a brief introduction to the ACS Fornax Cluster Survey - a program to image, in the F475W (g_475_) and F850LP (z_850_) bandpasses, 43 early-type galaxies in Fornax using the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. Combined with a companion survey of Virgo, the ACS Virgo Cluster Survey, this represents the most comprehensive imaging survey to date of early-type galaxies in cluster environments in terms of depth, spatial resolution, sample size, and homogeneity. We describe the selection of the program galaxies, their basic properties, and the main science objectives of the survey, which include the measurement of luminosities, colors, and structural parameters for globular clusters associated with these galaxies, an analysis of their isophotal properties and surface brightness profiles, and an accurate calibration of the surface brightness fluctuation distance indicator. Finally, we discuss the data reduction procedures adopted for the survey.
- ID:
- ivo://CDS.VizieR/J/A+A/650/A44
- Title:
- ACS J1149.5+2223 LOFAR and VLA images
- Short Name:
- J/A+A/650/A44
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Radio halos and relics are Mpc-scale diffuse radio sources in galaxy clusters, which have a steep spectral index {alpha}>1 (defined as S{prop.to}{nu}^-{alpha}^). It has been proposed that halos and relics arise from particle acceleration induced by turbulence and weak shocks that are injected into the intracluster medium (ICM) during mergers. MACS J1149.5+2223 is a high-redshift (z=0.544) galaxy cluster possibly hosting a radio halo and a relic. We analysed LOw Frequency Array (LOFAR), Giant Metrewave Radio Telescope, and Karl G. Jansky Very Large Array (JVLA) radio data at 144, 323, and 1500MHz, respectively. In addition, we analysed archival Chandra X-ray data to characterise the thermal and non-thermal properties of the cluster. We obtained radio images at different frequencies to investigate the spectral properties of the radio halo. We used Chandra X-ray images to constrain the thermal properties of the cluster and to search for discontinuities (due to cold fronts or shock fronts) in the surface brightness of the ICM. By combining radio and X-ray images, we carried out a point-to-point analysis to study the connection between the thermal and non-thermal emission. We measured a steep spectrum of the halo, which can be described by a power-law with {alpha}=1.49+/-0.12 between 144 and 1500MHz. The radio surface brightness distribution across the halo is found to correlate with the X-ray brightness of the ICM. The derived correlation shows a sub-linear slope in the range 0.4-0.6. We also report two possible cold fronts in north-east and north-west, but deeper X-ray observations are required to firmly constrain the properties of the upstream emission. We show that the combination of high-redshift, steep radio spectrum, and sub-linear radio-X scaling of the halo rules out hadronic models. An old (~1Gyr ago) major merger likely induced the formation of the halo through stochastic re-acceleration of relativistic electrons. We suggest that the two possible X-ray discontinuities may be part of the same cold front. In this case, the coolest gas pushed towards the north-west might be associated with the cool core of a sub-cluster involved in the major merger. The peculiar orientation of the south-east relic might indicate a different nature of this source and requires further investigation.
- ID:
- ivo://CDS.VizieR/J/ApJS/153/223
- Title:
- ACS Virgo Cluster Survey. I.
- Short Name:
- J/ApJS/153/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Virgo Cluster is the dominant mass concentration in the Local Supercluster and the largest collection of elliptical and lenticular galaxies in the nearby universe. In this paper, we present an introduction to the ACS (Advanced Camera for Surveys) Virgo Cluster Survey: a program to image, in the F475W and F850LP bandpasses (~Sloan g and z), 100 early-type galaxies in the Virgo Cluster using the Advanced Camera for Surveys on the Hubble Space Telescope.
- ID:
- ivo://CDS.VizieR/J/ApJS/154/509
- Title:
- ACS Virgo Cluster Survey. II.
- Short Name:
- J/ApJS/154/509
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ACS Virgo Cluster Survey is a large program to carry out multicolor imaging of 100 early-type members of the Virgo Cluster using the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. Deep F475W and F850LP images (~SDSS g and z) are being used to study the central regions of the program galaxies, their globular cluster systems, and the three-dimensional structure of Virgo itself. In this paper, we describe in detail the data reduction procedures used for the survey, including image registration, drizzling strategies, the computation of weight images, object detection, the identification of globular cluster candidates, and the measurement of their photometric and structural parameters.
- ID:
- ivo://CDS.VizieR/J/ApJ/613/279
- Title:
- ACS Virgo Cluster Survey. III. M87
- Short Name:
- J/ApJ/613/279
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ACIS instrument on board the Chandra X-Ray Observatory has been used to carry out the first systematic study of low-mass X-ray binaries (LMXBs) in M87, the giant elliptical galaxy near the dynamical center of the Virgo Cluster. These images - with a total exposure time of 154 ks - are the deepest X-ray observations yet obtained of M87. We identify 174 X-ray point sources, of which 150 are likely LMXBs.
