- ID:
- ivo://CDS.VizieR/J/A+A/570/A69
- Title:
- GALEX Ultraviolet Virgo Cluster Survey. IV.
- Short Name:
- J/A+A/570/A69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the role of the environment on galaxy evolution using a sample of 868 galaxies in the Virgo cluster and in its surrounding regions that are selected from the GALEX Ultraviolet Virgo Cluster Survey (GUViCS) with the purpose of understanding the origin of the red sequence in dense environments. The sample spans a wide range in morphological types (from dwarf ellipticals to Im and BCD) and stellar masses (10^7^<=M_star_<=10^11.5^M_{sun}_). We collected multifrequency data covering the whole electromagnetic spectrum for most of the galaxies, including UV, optical, mid- and far-infrared imaging data, as well as optical and HI spectroscopic data. We first identify the different dynamical substructures that compose the Virgo cluster, and we calculate the local density of galaxies using different methods. We then study the distribution of galaxies belonging to the red sequence, the green valley, and the blue cloud within the different cluster substructures or as a function of galaxy density. Our analysis indicates that all the most massive galaxies M_star_>=10^11^M_{sun}_) are slow rotators and are the dominant galaxies of the different cluster substructures, which are generally associated with a diffuse X-ray emission. They are probably the result of major merging events that occurred at early epochs, as also indicated by their very old stellar populations. Slow rotators of lower stellar mass (10^8.5^<=M_star_<=10^11^M_{sun}_) are also preferentially located within the different high-density substructures of the cluster. Their position in the velocity space indicates that they are virialised within the cluster; thus, they are Virgo members since its formation. They have been shaped by gravitational perturbations occurring within the infalling groups that later form the cluster (pre-processing). On the contrary, low-mass star-forming systems are extremely rare in the inner regions of the Virgo cluster A, where the density of the intergalactic medium is at its maximum. Our ram pressure stripping models consistently indicate that these star-forming systems can be rapidly deprived of their interstellar medium during their interaction with the intergalactic medium. The lack of gas quenches their star-formation activity transforming them into quiescent dwarf ellipticals. This mild transformation does not perturb the kinematic properties of these galaxies, which still have rotation curves typical of star-forming systems.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/462/875
- Title:
- Garching-Bonn Deep Survey (GaBoDS) IX
- Short Name:
- J/A+A/462/875
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of the present work is the construction of a mass-selected galaxy cluster sample based on weak gravitational lensing methods. This sample will be subject to spectroscopic follow-up observations. We apply the mass aperture statistics (S-statistics) and a new derivative of it (the P-statistics) to 19 square degrees of high quality, single colour wide field imaging data obtained with the WFI@MPG/ESO 2.2m telescope. For the statistics a family of filter functions is used that approximates the expected tangential radial shear profile and thus allows for the efficient detection of mass concentrations. The exact performance of the P-statistics still needs to be evaluated by means of simulations.
- ID:
- ivo://CDS.VizieR/J/A+A/520/A109
- Title:
- Gas kinematics of spiral galaxies
- Short Name:
- J/A+A/520/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We trace the interaction processes of galaxies at intermediate redshift by measuring the irregularity of their ionized gas kinematics, and investigate these irregularities as a function of the environment (cluster versus field) and of morphological type (spiral versus irregular). We obtain the gas velocity fields by placing three parallel and adjacent VLT/FORS2 slits on each galaxy. To quantify irregularities in the gas kinematics, we use three indicators: the standard deviation of the kinematic position angle ({sigma}_PA_), the mean deviation of the line of sight velocity profile from the cosine form which is measured using high order Fourier terms (k_3,5_/k_1_) and the average misalignment between the kinematical and photometric major axes ({Delta}{phi}). These indicators are then examined together with some photometric and structural parameters (measured from HST and FORS2 images in the optical) such as the disk scale length, rest-frame colors, asymmetry, concentration, Gini coefficient and M20 . Our sample consists of 92 distant galaxies. 16 cluster (z~0.3 and z~0.5) and 29 field galaxies (0.10<=z<=0.91, mean z=0.44) of these have velocity fields with sufficient signal to be analyzed. To compare our sample with the local universe, we also analyze a sample from the SINGS survey.
- ID:
- ivo://CDS.VizieR/J/MNRAS/417/1996
- Title:
- Gas properties in emission-line galaxies
- Short Name:
- J/MNRAS/417/1996
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the aim of distinguishing between possible physical mechanisms acting on galaxies when they fall into clusters, we study the properties of the gas and the stars in a sample of 422 emission-line galaxies from the European Southern Observatory Distant Cluster Survey in different environments up to z~1. We identify galaxies with kinematical disturbances (from emission lines in their 2D spectra) and find that they are more frequent in clusters than in the field.
- ID:
- ivo://CDS.VizieR/J/MNRAS/443/2679
- Title:
- GEEC2 spectroscopic survey of Galaxy groups
- Short Name:
- J/MNRAS/443/2679
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the data release of the Gemini-South GMOS spectroscopy in the fields of 11 galaxy groups at 0.8<z<1, within the COSMOS field. This forms the basis of the Galaxy Environment Evolution Collaboration 2 (GEEC2) project to study galaxy evolution in haloes with M~10^13^M_{sun}_ across cosmic time. The final sample includes 162 spectroscopically confirmed members with R<24.75, and is >50% complete for galaxies within the virial radius, and with stellar mass M_star_>10^10.3^M_{sun}_. Including galaxies with photometric redshifts, we have an effective sample size of ~400 galaxies within the virial radii of these groups. We present group velocity dispersions, dynamical and stellar masses. Combining with the GCLASS sample of more massive clusters at the same redshift, we find the total stellar mass is strongly correlated with the dynamical mass, with logM_200_=1.20(logM_star_-12)+14.07. This stellar fraction of ~1% is lower than predicted by some halo occupation distribution models, though the weak dependence on halo mass is in good agreement. Most groups have an easily identifiable most massive galaxy (MMG) near the centre of the galaxy distribution, and we present the spectroscopic properties and surface brightness fits to these galaxies. The total stellar mass distribution in the groups, excluding the MMG, compares well with an NFW (Navarro Frenk & White) profile with concentration 4, for galaxies beyond ~0.2R_200_. This is more concentrated than the number density distribution, demonstrating that there is some mass segregation.
- ID:
- ivo://CDS.VizieR/J/AJ/156/224
- Title:
- Gemini/HST GCP: galaxies in 4 massive clusters
- Short Name:
- J/AJ/156/224
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to study stellar populations and galaxy structures at intermediate and high redshift (z=0.2-2.0) and link these properties to those of low-redshift galaxies, there is a need for well-defined local reference samples. Especially for galaxies in massive clusters, such samples are often limited to the Coma cluster galaxies. We present consistently calibrated velocity dispersions and absorption-line indices for galaxies in the central 2 R_500_x2 R_500_ of four massive clusters at z<0.1: Abell 426/Perseus, Abell 1656/Coma, Abell 2029, and Abell 2142. The measurements are based on data from the Gemini Observatory, McDonald Observatory, and Sloan Digital Sky Survey. For bulge-dominated galaxies, the samples are 95% complete in Perseus and Coma and 74% complete in A2029 and A2142, to a limit of M_B,abs_=<-18.5 mag. The data serve as the local reference for our studies of galaxy populations in the higher-redshift clusters that are part of the Gemini/HST Galaxy Cluster Project (GCP). We establish the scaling relations between line indices and velocity dispersions as a reference for the GCP. We derive stellar population parameters, ages, metallicities [M/H], and abundance ratios from line indices, both averaged in bins of velocity dispersion and from individual measurements for galaxies in Perseus and Coma. The zero points of relations between the stellar population parameters and the velocity dispersions limit the allowed cluster-to-cluster variation of the four clusters to +/-0.08 dex in age, +/-0.06 dex in [M/H], +/-0.07 dex in [CN/Fe], and +/-0.03 dex in [Mg/Fe].
- ID:
- ivo://CDS.VizieR/J/ApJ/740/59
- Title:
- 1.4GHz and X-ray sources in 12 clusters of galaxies
- Short Name:
- J/ApJ/740/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using Chandra imaging spectroscopy and Very Large Array (VLA) L-band radio maps, we have identified radio sources at P_1.4GHz_>=5x10^23^W/Hz and X-ray point sources (XPSs) at L_0.3-8keV_>=5x10^42^erg/s in L>L* galaxies in 12 high-redshift (0.4<z<1.2) clusters of galaxies. The radio galaxies and XPSs in this cluster sample, chosen to be consistent with Coma Cluster progenitors at these redshifts, are compared to those found at low-z analyzed in Hart et al. (Paper I, 2009ApJ...705..854H). Within a projected radius of 1Mpc of the cluster cores, we find 17 cluster radio galaxies (11 with secure redshifts, including one luminous FR II radio source at z=0.826, and six more with host galaxy colors similar to cluster ellipticals). Within this same projected radius, we identify seven spectroscopically confirmed cluster XPSs, all with cluster red-sequence (CRS) host galaxy colors. Consistent with the results from Martini et al. (2009ApJ...701...66M), we estimate a minimum X-ray active fraction of 1.4%+/-0.8% for cluster red-sequence galaxies in high-z clusters, corresponding to an approximate 10-fold increase from 0.15%+/-0.15% at low-z. Although complete redshift information is lacking for several XPSs in z>0.4 cluster fields, the increased numbers and luminosities of the CRS radio galaxies and XPSs suggest a substantial (9-10-fold) increase in the heat injected into high-redshift clusters by AGNs compared to the present epoch.
- ID:
- ivo://CDS.VizieR/J/AJ/125/2427
- Title:
- 1.4GHz flux densities of Abell 2255 galaxies
- Short Name:
- J/AJ/125/2427
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep VLA 1.4GHz radio continuum imaging of Abell 2255 is presented. This cluster is among the better nearby candidates for rich cluster-cluster merger systems, with evidence including an elongated X-ray morphology, the presence of a radio halo, and substructure present in its galaxy distribution. Our radio observations reach an rms sensitivity of ~40{mu}Jy/beam, enabling us to detect (at 5{sigma}) star formation rates as low as 1.4M_{sun}_/yr from the center of the cluster out to a radial distance of 3h^-1^_75_Mpc. The radio data are complemented by optical imaging and a large spectroscopic database, allowing us to separate all galaxies with M_Rc_<=-20 0 into cluster members and foreground/background galaxies. The spectra are also used to associate the galaxies' radio emission with either star formation or active galactic nuclei (AGNs). We compare the resulting cluster radio galaxy population with those of 19 other nearby Abell clusters and find strong evidence for an increase in the frequency of radio galaxies in Abell 2255. This increase is seen in two separate types of galaxies: powerful radio AGNs and optically faint star-forming galaxies. The optical spectra of the latter often indicate current or recent starbursts, and these galaxies appear to be distributed along an axis perpendicular to the probable merger axis. We assess these factors in light of models of galaxy evolution and suggest that the cluster-cluster merger is responsible for triggering galaxy activity in Abell 2255.
- ID:
- ivo://CDS.VizieR/J/A+A/419/71
- Title:
- 1.4GHz obs. and optical ident. in A3558
- Short Name:
- J/A+A/419/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Very Large Array (VLA) 1.4GHz (21cm) observations of the region between the centres of A3558 and A3562, in the major cluster merger complex of the Shapley Concentration. Our final catalogue includes a total of 174 radio sources above the flux density limit of 0.25 mJy/b. By cross-correlation with optical and spectroscopic catalogues we found 33 optical counterparts belonging to the Shapley Concentration.
- ID:
- ivo://CDS.VizieR/J/A+AS/41/421
- Title:
- 1.4GHz survey in the Virgo region
- Short Name:
- J/A+AS/41/421
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radio continuum observations made with the Westerbork Synthesis Radio Telescope at 1.4GHz are presented for 274 galaxies in the Virgo Cluster region. The observations are partly full syntheses and partly east-west strip distributions. For the 55 detected galaxies the emission is separated into central and extended components. A brief summary of the analysis is also given.
