- ID:
- ivo://CDS.VizieR/J/ApJ/741/98
- Title:
- Spectroscopy of galaxy clusters to find LCBGs
- Short Name:
- J/ApJ/741/98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used the DEIMOS spectrograph on the Keck II Telescope to obtain spectra of galaxies in the fields of five distant, rich galaxy clusters over the redshift range 0.5<z<0.9 in a search for luminous compact blue galaxies (LCBGs). Unlike traditional studies of galaxy clusters, we preferentially targeted blue cluster members identified via multi-band photometric pre-selection based on imaging data from the WIYN telescope. Of the 1288 sources that we targeted, we determined secure spectroscopic redshifts for 848 sources, yielding a total success rate of 66%. Our redshift measurements are in good agreement with those previously reported in the literature, except for 11 targets which we believe were previously in error. Within our sample, we confirm the presence of 53 LCBGs in the five galaxy clusters.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/193/8
- Title:
- Spectroscopy of 26 lensing cluster cores
- Short Name:
- J/ApJS/193/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a spectroscopic program targeting 26 strong-lensing cluster cores that were visually identified in the Sloan Digital Sky Survey (SDSS; Gladders et al. 2011, in prep) and the Second Red-Sequence Cluster Survey (RCS-2; Bayliss et al. 2011, in prep). The 26 galaxy cluster lenses span a redshift range of 0.2<z<0.65, and our spectroscopy reveals 69 unique background sources with redshifts as high as z=5.200. We also identify redshifts for 262 cluster member galaxies and measure the velocity dispersions and dynamical masses for 18 clusters where we have redshifts for N>=10 cluster member galaxies. We account for the expected biases in dynamical masses of strong-lensing-selected clusters as predicted by results from numerical simulations and discuss possible sources of bias in our observations.
- ID:
- ivo://CDS.VizieR/J/ApJ/817/87
- Title:
- Spectroscopy of luminous compact blue galaxies
- Short Name:
- J/ApJ/817/87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Luminous Compact Blue Galaxies (LCBGs) are an extreme star-bursting population of galaxies that were far more common at earlier epochs than today. Based on spectroscopic and photometric measurements of LCBGs in massive (M>10^15^M_{sun}_), intermediate redshift (0.5<z<0.9) galaxy clusters, we present their rest-frame properties including star formation rate, dynamical mass, size, luminosity, and metallicity. The appearance of these small, compact galaxies in clusters at intermediate redshift helps explain the observed redshift evolution in the size-luminosity relationship among cluster galaxies. In addition, we find the rest-frame properties of LCBGs appearing in galaxy clusters are indistinguishable from field LCBGs at the same redshift. Up to 35% of the LCBGs show significant discrepancies between optical and infrared indicators of star formation, suggesting that star formation occurs in obscured regions. Nonetheless, the star formation for LCBGs shows a decrease toward the center of the galaxy clusters. Based on their position and velocity, we estimate that up to 10% of cluster LCBGs are likely to merge with another cluster galaxy. Finally, the observed properties and distributions of the LCBGs in these clusters lead us to conclude that we are witnessing the quenching of the progenitors of dwarf elliptical galaxies that dominate the number density of present-epoch galaxy clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/902/17
- Title:
- Spectroscopy of quiescent gal. in 9 lensing clusters
- Short Name:
- J/ApJ/902/17
- Date:
- 03 Mar 2022 11:35:20
- Publisher:
- CDS
- Description:
- We measure the central stellar velocity dispersion function for quiescent galaxies in a set of nine northern clusters in the redshift range 0.18<z<0.29 and with strong lensing arcs in Hubble Space Telescope images. The velocity dispersion function links galaxies directly to their dark matter halos. From dense SDSS and MMT/Hectospec spectroscopy, we identify 222-463 spectroscopic members in each cluster. We derive physical properties of cluster members including redshift, D_n_4000, and central stellar velocity dispersion and we include a table of these measurements for 3419 cluster members. We construct the velocity dispersion functions for quiescent galaxies with D_n_4000>1.5 and within R200. The cluster velocity dispersion functions all show excesses at {sigma}>~250km/s compared to the field velocity dispersion function. The velocity dispersion function slope at large velocity dispersion ({sigma}>160km/s) is steeper for more massive clusters, consistent with the trend observed for cluster luminosity functions. The spatial distribution of galaxies with large velocity dispersion at radii larger than R200 further underscores the probable major role of dry mergers in the growth of massive cluster galaxies during cluster assembly.
- ID:
- ivo://CDS.VizieR/J/ApJ/834/210
- Title:
- Spectroscopy of strong lensing galaxy clusters
- Short Name:
- J/ApJ/834/210
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an extensive spectroscopic follow-up campaign of 29 strong lensing (SL) selected galaxy clusters discovered primarily in the Second Red-Sequence Cluster Survey (RCS-2). Our spectroscopic analysis yields redshifts for 52 gravitational arcs present in the core of our galaxy clusters, which correspond to 35 distinct background sources that are clearly distorted by the gravitational potential of these clusters. These lensed galaxies span a wide redshift range of 0.8<=z<=2.9, with a median redshift of z_s_=1.8+/-0.1. We also measure reliable redshifts for 1004 cluster members, allowing us to obtain robust velocity dispersion measurements for 23 of these clusters, which we then use to determine their dynamical masses by using a simulation-based {sigma}_DM_-M_200_ scaling relation. The redshift and mass ranges covered by our SL sample are 0.22<=z<=1.01 and 5x10^13^M_200_/h_70_^-1^M_{sun}_<=1.9x10^15^, respectively. We analyze and quantify some possible effects that might bias our mass estimates, such as the presence of substructure, the region where cluster members are selected for spectroscopic follow-up, the final number of confirmed members, and line-of-sight effects. We find that 10 clusters of our sample with N_mem_>~20 show signs of dynamical substructure. However, the velocity data of only one system is inconsistent with a uni-modal distribution. We therefore assume that the substructures are only marginal and not of comparable size to the clusters themselves. Consequently, our velocity dispersion and mass estimates can be used as priors for SL mass reconstruction studies and also represent an important step toward a better understanding of the properties of the SL galaxy cluster population.
- ID:
- ivo://CDS.VizieR/J/MNRAS/478/4952
- Title:
- SPIDERS BCGs gri photometry
- Short Name:
- J/MNRAS/478/4952
- Date:
- 10 Dec 2021 13:51:48
- Publisher:
- CDS
- Description:
- We present a sample of 329 low-to intermediate-redshift (0.05<z<0.3) brightest cluster galaxies (BCGs) in X-ray-selected clusters from the SPectroscopic IDentification of eRosita Sources survey, a spectroscopic survey within Sloan Digital Sky Survey-IV (SDSS-IV). We define our BCGs by simultaneous consideration of legacy X-ray data from ROSAT, maximum-likelihood outputs from an optical cluster-finder algorithm and visual inspection. Using SDSS imaging data, we fit Sersic profiles to our BCGs in three bands (g, r, i) with SIGMA a GALFIT-based software wrapper. We examine the reliability of our fits by running our pipeline on ~10^4^ point spread function-convolved model profiles injected into eight random cluster fields; we then use the results of this analysis to create a robust subsample of 198 BCGs. We outline three cluster properties of interest: overall cluster X-ray luminosity (L_X_), cluster richness as estimated by REDMAPPER ({lambda}),and cluster halo mass (M_200_), which is estimated via velocity dispersion. In general, there are significant correlations with BCG stellar mass between all three environmental properties, but no significant trends arise with either Sersic index or effective radius. There is no major environmental dependence on the strength of the relation between effective radius and BCG stellar mass. Stellar mass therefore arises as the most important factor governing BCG morphology. Our results indicate that our sample consists of a large number of relaxed, mature clusters containing broadly homogeneous BCGs up to z~0.3, suggesting that there is little evidence for much ongoing structural evolution for BCGs in these systems.
- ID:
- ivo://CDS.VizieR/J/A+AS/110/279
- Title:
- Spirals in Virgo. III.
- Short Name:
- J/A+AS/110/279
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of the rotation curves of a sample of 32 spiral galaxies derived from the spectroscopic observations of a sample of 47 galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/686/966
- Title:
- Spitzer-FLS catalog of clusters of galaxies
- Short Name:
- J/ApJ/686/966
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 99 candidate clusters and groups of galaxies in the redshift range 0.1<z_phot_<1.3 discovered in the Spitzer First-Look Survey (FLS). The clusters are selected by their Rc-3.6um galaxy color-magnitude relation using the cluster red-sequence algorithm. Using this cluster sample, we compute the 3.6, 4.5, 5.8, and 8.0um, cluster luminosity functions (LFs).
- ID:
- ivo://irsa.ipac/Spitzer/Images/SRELICS
- Title:
- Spitzer Reionization Lensing Cluster Survey
- Short Name:
- SRELICS
- Date:
- 01 May 2023 20:00:00
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Spitzer Reionization Lensing Cluster Survey (SRELICS, PI: Bradac) is the Spitzer counterpart to the RELICS HST Treasury program (PI: Coe) to survey 41 massive galaxy clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/837/88
- Title:
- SPT-GMOS spectroscopy of gal. in massive clusters
- Short Name:
- J/ApJ/837/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The velocity distribution of galaxies in clusters is not universal; rather, galaxies are segregated according to their spectral type and relative luminosity. We examine the velocity distributions of different populations of galaxies within 89 Sunyaev Zel'dovich (SZ) selected galaxy clusters spanning 0.28<z<1.08. Our sample is primarily draw from the SPT-GMOS spectroscopic survey, supplemented by additional published spectroscopy, resulting in a final spectroscopic sample of 4148 galaxy spectra -- 2868 cluster members. The velocity dispersion of star-forming cluster galaxies is 17+/-4% greater than that of passive cluster galaxies, and the velocity dispersion of bright (m<m^*^-0.5) cluster galaxies is 11+/-4% lower than the velocity dispersion of our total member population. We find good agreement with simulations regarding the shape of the relationship between the measured velocity dispersion and the fraction of passive versus star-forming galaxies used to measure it, but we find a small offset between this relationship as measured in data and simulations, which suggests that our dispersions are systematically low by as much as 3% relative to simulations. We argue that this offset could be interpreted as a measurement of the effective velocity bias that describes the ratio of our observed velocity dispersions and the intrinsic velocity dispersion of dark matter particles in a published simulation result. Measuring velocity bias in this way suggests that large spectroscopic surveys can improve dispersion-based mass-observable scaling relations for cosmology even in the face of velocity biases, by quantifying and ultimately calibrating them out.
