- ID:
- ivo://CDS.VizieR/J/PAZh/25/447
- Title:
- Identification of radio sources. I.
- Short Name:
- J/PAZh/25/447
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Detailed identification of radio sources within the Abell radii in 26 rich galactic clusters of the FIRST catalog with optical objects of the APM and DSS surveys had been carried out. Of the 326 radio sources in the cluster fields, 99 are identified, 40 have probable identifications, and 187 are unidentified. Among last sources, 20 are definitely located in the clusters and 34 are cluster members with high probability. Thus, 30-40% of the FIRST radio sources could be identified using APM and DSS data, and there were two sources in each cluster on the average.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/148/117
- Title:
- Imaging and spectroscopy in Lynx W
- Short Name:
- J/AJ/148/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- RX J0848.6+4453 (Lynx W) at redshift 1.27 is part of the Lynx Supercluster of galaxies. We present an analysis of the stellar populations and star formation history for a sample of 24 members of the cluster. Our study is based on deep optical spectroscopy obtained with Gemini North combined with imaging data from Hubble Space Telescope. Focusing on the 13 bulge-dominated galaxies for which we can determine central velocity dispersions, we find that these show a smaller evolution with redshift of sizes and velocity dispersions than reported for field galaxies and galaxies in poorer clusters. Our data show that the galaxies in RX J0848.6+4453 populate the fundamental plane (FP) similar to that found for lower-redshift clusters. The zero-point offset for the FP is smaller than expected if the cluster's galaxies are to evolve passively through the location of the FP we established in our previous work for z=0.8-0.9 cluster galaxies and then to the present-day FP. The FP zero point for RXJ0848.6+4453 corresponds to an epoch of last star formation at z_form_=1.95_-0.15_^+0.22^. Further, we find that the spectra of the galaxies in RXJ0848.6+4453 are dominated by young stellar populations at all galaxy masses and in many cases show emission indicating low-level ongoing star formation. The average age of the young stellar populations as estimated from the strength of the high-order Balmer line H{zeta} is consistent with a major star formation episode 1-2Gyr prior, which in turn agrees with z_form_=1.95. These galaxies dominated by young stellar populations are distributed throughout the cluster. We speculate that low-level star formation has not yet been fully quenched in the center of this cluster, possibly because the cluster is significantly poorer than other clusters previously studied at similar redshifts, which appear to have very little ongoing star formation in their centers. The mixture in RXJ0848.6+4453 of passive galaxies with young stellar populations and massive galaxies still experiencing some star formation appears similar to the galaxy populations recently identified in two z{approx}2 clusters.
- ID:
- ivo://CDS.VizieR/J/AJ/145/77
- Title:
- Imaging and spectroscopy in three galaxy clusters
- Short Name:
- J/AJ/145/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of stellar populations and evolutionary history of galaxies in three similarly rich galaxy clusters MS0451.6-0305 (z=0.54), RXJ0152.7-1357 (z=0.83), and RXJ1226.9+3332 (z=0.89). Our analysis is based on high signal-to-noise ground-based optical spectroscopy and Hubble Space Telescope imaging for a total of 17-34 members in each cluster. Using the dynamical masses together with the effective radii and the velocity dispersions, we find no indication of evolution of sizes or velocity dispersions with redshift at a given galaxy mass. We establish the Fundamental Plane (FP) and scaling relations between absorption line indices and velocity dispersions. We confirm that the FP is steeper at z~0.86 compared to the low-redshift FP, indicating that under the assumption of passive evolution the formation redshift, z_form_, depends on the galaxy velocity dispersion (or alternatively mass). At a velocity dispersion of {sigma}=125km/s (Mass=10^10.55^M_{sun}_) we find z_form_=1.24+/-0.05, while at {sigma}=225km/s (Mass=10^11.36^M_{sun}_) the formation redshift is z_form_=1.95^+0.3^_-0.2_, for a Salpeter initial mass function. The three clusters follow similar scaling relations between absorption line indices and velocity dispersions as those found for low-redshift galaxies. The zero point offsets for the Balmer lines depend on cluster redshifts. However, the offsets indicate a slower evolution, and therefore higher formation redshift, than the zero point differences found from the FP, if interpreting the data using a passive evolution model. Specifically, the strength of the higher order Balmer lines H{delta} and H{gamma} implies z_form_>2.8. The scaling relations for the metal indices in general show small and in some cases insignificant zero point offsets, favoring high formation redshifts for a passive evolution model.
- ID:
- ivo://CDS.VizieR/J/MNRAS/379/1343
- Title:
- Infrared study of UKIDSS massive supercluster
- Short Name:
- J/MNRAS/379/1343
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyse the first publicly released deep field of the UK Infrared Deep Sky Survey (UKIDSS) Deep eXtragalactic Survey to identify candidate galaxy overdensities at z~1 across ~1deg^2^ in the ELAIS-N1 field. Using I-K, J-K and K-3.6um colours, we identify and spectroscopically follow up five candidate structures with Gemini/Gemini Multi-Object Spectrograph and confirm that they are all true overdensities with between five and 19 members each.
- ID:
- ivo://CDS.VizieR/J/ApJ/659/1138
- Title:
- Intermediate-redshift spiral galaxies Vmax
- Short Name:
- J/ApJ/659/1138
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Combining resolved optical spectroscopy with panoramic HST imaging, we study the dynamical properties of spiral galaxies as a function of position across two intermediate-redshift clusters, and we compare the cluster population to field galaxies in the same redshift range. By modeling the observed rotation curves, we derive maximal rotation velocities for 40 cluster spirals and 37 field spirals, yielding one of the largest matched samples of cluster and field spirals at intermediate redshift. We construct the Tully-Fisher (TF) relation in both V and Ks bands, and find that the cluster Tully-Fisher relation exhibits significantly higher scatter than the field relation, in both V and Ks bands.
- ID:
- ivo://CDS.VizieR/J/A+A/587/A68
- Title:
- Ionised gas images of NGC 4569
- Short Name:
- J/A+A/587/A68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using MegaCam at the CFHT, we obtained a deep narrow band H{alpha}+[NII] wide-field image of NGC 4569 (M90), the brightest late-type galaxy in the Virgo cluster. The image reveals the presence of long tails of diffuse ionized gas, without any associated stellar component extending from the disc of the galaxy up to ~=80kpc (projected distance) and with a typical surface brightness of a few 10^-18^erg/s/cm^2^/arcsec^2^. These features provide direct evidence that NGC 4569 is undergoing a ram-pressure stripping event. The image also shows a prominent 8 kpc spur of ionized gas that is associated with the nucleus that spectroscopic data identify as an outflow. With some assumptions on the 3D distribution of the gas, we use the H{alpha} surface brightness of these extended low-surface brightness features to derive the density and the mass of the gas that has been stripped during the interaction of the galaxy with the intracluster medium. The comparison with ad hoc chemo-spectrophotometric models of galaxy evolution indicates that the mass of the H{alpha} emitting gas in the tail is a large fraction of that of the cold phase that has been stripped from the disc, suggesting that the gas is ionized within the tail during the stripping process. The lack of star-forming regions suggests that mechanisms other than photoionization are responsible for the excitation of the gas (shocks, heat conduction, magneto hydrodynamic waves). This analysis indicates that ram pressure stripping is efficient in massive (M_{star}_~=10^10.5^M_{sun}_) galaxies located in intermediate-mass (~=10^14^M_{sun}) clusters under formation. It also shows that the mass of gas expelled by the nuclear outflow is only ~1% than that removed during the ram pressure stripping event. Together these results indicate that ram pressure stripping, rather than starvation through nuclear feedback, can be the dominant mechanism that is responsible for the quenching of the star formation activity of galaxies in high density environments.
- ID:
- ivo://CDS.VizieR/J/ApJ/591/53
- Title:
- I photometry of Cl 0024+16
- Short Name:
- J/ApJ/591/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a new wide-field Hubble Space Telescope survey of the galaxy cluster Cl 0024+16 (z~0.4) consisting of a sparsely sampled mosaic of 39 Wide Field Planetary Camera 2 images that extends to a cluster radius of ~5Mpc. Together with extensive ground-based spectroscopy taken from the literature, augmented with over a hundred newly determined redshifts, this unique data set enables us to examine environmental influences on the properties of cluster members from the inner core to well beyond the virial radius (~1.7Mpc). We catalog photometric measures for 22000 objects to I>~25 and assign morphological types for 2181 to I=22.5, of which 195 are spectroscopically confirmed cluster members.
- ID:
- ivo://CDS.VizieR/J/A+AS/100/583
- Title:
- IR and Optical Photometry of galaxies
- Short Name:
- J/A+AS/100/583
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJS/199/23
- Title:
- IR and UV star formation in ACCEPT BCGs
- Short Name:
- J/ApJS/199/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present infrared (IR) and ultraviolet (UV) photometry for a sample of brightest cluster galaxies (BCGs). The BCGs are from a heterogeneous but uniformly characterized sample, the Archive of Chandra Cluster Entropy Profile Tables (ACCEPT), of X-ray galaxy clusters from the Chandra X-ray telescope archive with published gas temperature, density, and entropy profiles. We use archival Galaxy Evolution Explorer (GALEX), Spitzer Space Telescope, and Two Micron All Sky Survey (2MASS) observations to assemble spectral energy distributions (SEDs) and colors for BCGs. We establish a mean near-UV (NUV) to 2MASS K color of 6.59+/-0.34 for quiescent BCGs. We use this mean color to quantify the UV excess associated with star formation in the active BCGs. We use both fits to a template of an evolved stellar population and library of starburst models and mid-IR star formation relations to estimate the obscured star formation rates (SFRs). We present IR and UV photometry and estimated equivalent continuous SFRs for a sample of BCGs.
- ID:
- ivo://CDS.VizieR/J/AJ/142/148
- Title:
- IR observations of galaxies in the Coma cluster
- Short Name:
- J/AJ/142/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a thorough study of the specific star formation rates (sSFRs) for MIPS 24um selected galaxies in the Coma cluster. We build galaxy spectral energy distributions using optical (u', g', r', i', z'), near-infrared (J, H, Ks), and mid- to far-infrared (Infrared Array Camera and MIPS) photometry. New and archival spectra confirm 210 cluster members. Subsequently, the total infrared luminosity, galaxy stellar mass, and sSFR for the members are determined by measuring best-fit templates. Using an array of complementary diagnostics, we search for any contaminating active galactic nuclei, but find few. We compare obscured SFRs to unobscured rates derived from extinction-corrected H{alpha} emission line measurements. The agreement between these two values leads us to conclude that there is no evidence for an additionally obscured component. In our spectroscopic sample, complete to 80% for r'<19.5, we find that all starbursts are blue and are dwarfs, having masses <10^9^M_{sun}_. Examining the location of these starbursts within the cluster, we confirm that there is a lower fraction in the cluster core.
