- ID:
- ivo://CDS.VizieR/J/A+A/506/1071
- Title:
- Galaxy morphology in 5 medium redshift clusters
- Short Name:
- J/A+A/506/1071
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Following the study presented in our previous paper, based on the Nordic Optical Telescope (NOT) sample, which consists of five clusters of galaxies within the redshift range 0.18<=z<=0.25 imaged in the central 0.5-2Mpc in very good seeing conditions, we have studied the quantitative morphology of their bright galaxy population. We analyzed the surface brightness profiles of the galaxy population in those clusters, after performing simulations in order to check the reliability of the fits. We also derived a quantitative morphological classification.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/388/1537
- Title:
- Galaxy pairs from SDSS-DR2
- Short Name:
- J/MNRAS/388/1537
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the incidence of major mergers creating massive (M_star_>10^11^M_{sun}_) galaxies in present-day (z<=0.12) groups and clusters. Using a volume-limited sample of 845 groups with dark matter halo masses above 2.5x10^13^M_{sun}_, we isolate 221 galaxy pairs with <=1.5 r-band magnitude differences, <=30kpc projected separations and combined masses above 10^11^M_{sun}_. We fit the r-band images of each pair as the line-of-sight projection of symmetric models and identify 38 mergers by the presence of residual asymmetric structure associated with both progenitors, such as non-concentric isophotes, broad and diffuse tidal tails and dynamical friction wakes.
- ID:
- ivo://CDS.VizieR/J/A+A/527/A101
- Title:
- Galaxy population of Abell 1367
- Short Name:
- J/A+A/527/A101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectroscopic and photometric data of the galaxy population of the galaxy cluster Abell 1367, over a field of 34'x90', covering the cluster centre out to a radius of ~2.2Mpc, are presented as the first stage of a study of their stellar population and star formation properties. Spectroscopic catalogue contains new detection data of emission and/or absorption lines for 84 galaxies in our survey regions. Photometric data give optical and near-infrared isophotal magnitudes for 303 galaxies, determined within R_24_ isophotal diameters. H{alpha} emission catalogue reports equivalent widths and fluxes of 72 galaxies, confirmed as cluster members of Abell 1367.
- ID:
- ivo://CDS.VizieR/J/ApJ/791/18
- Title:
- Galaxy samples rest-frame ultraviolet structure
- Short Name:
- J/ApJ/791/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the rest-frame UV wavelength dependence of the Petrosian-like half-light radius (r_50_), and the concentration parameter for a sample of 198 star-forming galaxies at 0.5 < z < 1.5. We find a ~5% decrease in r_50_ from 1500 {AA} to 3000 {AA}, with half-light radii at 3000 {AA} ranging from 0.6 kpc to 6 kpc. We also find a decrease in concentration of ~0.07 (1.9 < C_3000_< 3.9). The lack of a strong relationship between r_50_and wavelength is consistent with a model in which clumpy star formation is distributed over length scales comparable to the galaxy's rest-frame optical light. While the wavelength dependence of r_50_is independent of size at all redshifts, concentration decreases more sharply in the far-UV (~1500 {AA}) for large galaxies at z ~ 1. This decrease in concentration is caused by a flattening of the inner ~20% of the light profile in disk-like galaxies, indicating that the central regions have different UV colors than the rest of the galaxy. We interpret this as a bulge component with older stellar populations and/or more dust. The size-dependent decrease in concentration is less dramatic at z ~ 2, suggesting that bulges are less dusty, younger, and/or less massive than the rest of the galaxy at higher redshifts.
- ID:
- ivo://CDS.VizieR/J/ApJS/122/109
- Title:
- Galaxy structural parameters
- Short Name:
- J/ApJS/122/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The evolution of the structure of galaxies as a function of redshift is investigated using two parameters: the metric radius of the galaxy (R_eta_) and the power at high spatial frequencies in the disk of the galaxy (chi). A direct comparison is made between nearby (z~0) and distant (0.2<~z<~1) galaxies by following a fixed range in rest frame wavelengths. The data of the nearby galaxies comprise 136 broadband images at ~4500 E observed with the 0.9 m telescope at Kitt Peak National Observatory (23 galaxies) and selected from the catalog of digital images of Frei et al. (113 galaxies, 1996AJ....111..174F). The high-redshift sample comprises 94 galaxies selected from the Hubble Deep Field (HDF) observations with the Hubble Space Telescope using the Wide Field Planetary Camera 2 in four broad bands that range between ~3000 and ~9000 E (Williams et al., 1997, Cat. <J/AJ/112/1335>).
- ID:
- ivo://CDS.VizieR/J/ApJ/782/64
- Title:
- Galaxy structural parameters from 3.6um images
- Short Name:
- J/ApJ/782/64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed two-dimensional multicomponent decomposition of 144 local barred spiral galaxies using 3.6{mu}m images from the Spitzer Survey of Stellar Structure in Galaxies. Our model fit includes up to four components (bulge, disk, bar, and a point source) and, most importantly, takes into account disk breaks. We find that ignoring the disk break and using a single disk scale length in the model fit for Type II (down-bending) disk galaxies can lead to differences of 40% in the disk scale length, 10% in bulge-to-total luminosity ratio (B/T), and 25% in bar-to-total luminosity ratios. We find that for galaxies with B/T>=0.1, the break radius to bar radius, r_br_/R_bar_, varies between 1 and 3, but as a function of B/T the ratio remains roughly constant. This suggests that in bulge-dominated galaxies the disk break is likely related to the outer Lindblad resonance of the bar and thus moves outward as the bar grows. For galaxies with small bulges, B/T<0.1, r_br_/R_bar_ spans a wide range from 1 to 6. This suggests that the mechanism that produces the break in these galaxies may be different from that in galaxies with more massive bulges. Consistent with previous studies, we conclude that disk breaks in galaxies with small bulges may originate from bar resonances that may be also coupled with the spiral arms, or be related to star formation thresholds.
- ID:
- ivo://CDS.VizieR/J/ApJS/193/28
- Title:
- Galaxy survey around 20 UV-bright quasars
- Short Name:
- J/ApJS/193/28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We publish the survey for galaxies in 20 fields containing ultraviolet bright quasars (with z_em_~0.1-0.5) that can be used to study the association between galaxies and absorption systems from the low-z intergalactic medium (IGM). The survey is magnitude limited (R~19.5mag) and highly complete out to 10' from the quasar in each field. It was designed to detect dwarf galaxies (L~0.1L*) at an impact parameter {rho}~1Mpc (z=0.1) from a quasar. The complete sample (all 20 fields) includes R-band photometry for 84718 sources and confirmed redshifts for 2800 sources. This includes 1198 galaxies with 0.005<z<(z_em_-0.01) at a median redshift of 0.18, which may associated with IGM absorption lines. All of the imaging was acquired with cameras on the Swope 40" telescope and the spectra were obtained via slit mask observations using the WFCCD spectrograph on the Dupont 100" telescope at Las Campanas Observatory.
- ID:
- ivo://CDS.VizieR/J/ApJ/701/1219
- Title:
- Galaxy survey in 3 QSO fields
- Short Name:
- J/ApJ/701/1219
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an imaging and spectroscopic survey of galaxies in fields around QSOs HE 0226-4110, PKS 0405-123, and PG 1216+069. The fields are selected to have ultraviolet echelle spectra available, which uncover 195 Ly{alpha} absorbers and 13 OVI absorbers along the three sightlines. We obtain robust redshifts for 1104 galaxies of rest-frame absolute magnitude M_R_-5logh<~-16 and at projected physical distances {rho}<~4h^-1^Mpc from the QSOs. Hubble Space Telescope (HST)/WFPC2 images of the fields around PKS 0405-123 and PG 1216+069 are available for studying the optical morphologies of absorbing galaxies. Combining the absorber and galaxy data, we perform a cross-correlation study to understand the physical origin of Ly{alpha} and OVI absorbers and to constrain the properties of extended gas around galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/382/513
- Title:
- Galaxy warps in the HDF North and South
- Short Name:
- J/A+A/382/513
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a statistical study of the presence of galaxy warps in the Hubble deep fields. Among a complete sample of 45 edge-on galaxies above a diameter of 1.3", we find 5 galaxies to be certainly warped and 6 galaxies as good candidates. In addition, 4 galaxies reveal a characteristic U-warp. Compared to statistical studies of local warps, and taking into account the strong bias against observing the outer parts of galaxies at high redshift, these numbers point towards a very high frequency of warps at z~1: almost all galaxy discs might be warped. Furthermore, the amplitude of warps are stronger than for local warps. This is easily interpreted in terms of higher galaxy interactions and matter accretion in the past. This result supports these two mechanisms as the best candidates for the origin of early warps. The mean observed axis ratio of our sample of edge-on galaxies is significantly larger in the high-z sample than is found for samples of local spiral galaxies. This might be due to disk thickening due to more frequent galaxy interactions.
- ID:
- ivo://CDS.VizieR/J/ApJ/711/284
- Title:
- Galaxy Zoo: AGN host galaxies
- Short Name:
- J/ApJ/711/284
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use data from the Sloan Digital Sky Survey and visual classifications of morphology from the Galaxy Zoo project to study black hole growth in the nearby universe (z<0.05) and to break down the active galactic nucleus (AGN) host galaxy population by color, stellar mass, and morphology. We find that the black hole growth at luminosities L[OIII]>10^40^erg/s in early- and late-type galaxies is fundamentally different. AGN host galaxies as a population have a broad range of stellar masses (10^10^-10^11^M_{sun}_), reside in the green valley of the color-mass diagram and their central black holes have median masses around 10^6.5^M_{sun}_. However, by comparing early- and late-type AGN host galaxies to their non-active counterparts, we find several key differences: in early-type galaxies, it is preferentially the galaxies with the least massive black holes that are growing, while in late-type galaxies, it is preferentially the most massive black holes that are growing. At high-Eddington ratios (L/L_Edd_>0.1), the only population with a substantial fraction of AGNs are the low-mass green valley early-type galaxies.
