- ID:
- ivo://CDS.VizieR/J/AJ/146/20
- Title:
- Structural parameters for 79 globular clusters in M31
- Short Name:
- J/AJ/146/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present surface brightness profiles for 79 globular clusters in M31, using images observed with the Hubble Space Telescope, some of which are from new observations. The structural and dynamical parameters are derived from fitting the profiles to several different models for the first time. The results show that in the majority of cases, King models fit the M31 clusters just as well as Wilson models and better than S\'ersic models. However, there are 11 clusters best fitted by Sersic models with the Sersic index n>2, meaning that they have cuspy central density profiles. These clusters may be the well-known core-collapsed candidates. There is a bimodality in the size distribution of M31 clusters at large radii, which is different from their Galactic counterparts. In general, the properties of clusters in M31 and the Milky Way fall in the same regions of parameter spaces. The tight correlations of cluster properties indicate a "fundamental plane" for clusters, which reflects some universal physical conditions and processes operating at the epoch of cluster formation.
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- ID:
- ivo://CDS.VizieR/J/ApJS/203/24
- Title:
- Structural parameters of galaxies in CANDELS
- Short Name:
- J/ApJS/203/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present global structural parameter measurements of 109533 unique, H_F160W_-selected objects from the CANDELS multi-cycle treasury program. Sersic model fits for these objects are produced with GALFIT in all available near-infrared filters (H_F160W_, J_F125W_ and, for a subset, Y_F105W_). The parameters of the best-fitting Sersic models (total magnitude, half-light radius, Sersic index, axis ratio, and position angle) are made public, along with newly constructed point-spread functions for each field and filter. Random uncertainties in the measured parameters are estimated for each individual object based on a comparison between multiple, independent measurements of the same set of objects. To quantify systematic uncertainties, we create a mosaic with simulated galaxy images with a realistic distribution of input parameters and then process and analyze the mosaic in an identical manner as the real data.
- ID:
- ivo://CDS.VizieR/J/ApJ/787/24
- Title:
- Structural parameters of true edge-on galaxies
- Short Name:
- J/ApJ/787/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of true edge-on disk galaxies automatically selected from the Seventh Data Release of the Sloan Digital Sky Survey (SDSS, Cat. II/294). A visual inspection of the g, r, and i images of about 15000 galaxies allowed us to split the initial sample of edge-on galaxy candidates into 4768 (31.8% of the initial sample) genuine edge-on galaxies, 8350 (55.7%) non-edge-on galaxies, and 1865 (12.5%) edge-on galaxies not suitable for simple automatic analysis because these objects either show signs of interaction and warps, or nearby bright stars project on it. We added more candidate galaxies from RFGC, EFIGI, RC3, and Galaxy Zoo catalogs found in the SDSS footprints. Our final sample consists of 5747 genuine edge-on galaxies. We estimate the structural parameters of the stellar disks (the stellar disk thickness, radial scale length, and central surface brightness) in the galaxies by analyzing photometric profiles in each of the g, r, and i images. We also perform simplified three-dimensional modeling of the light distribution in the stellar disks of edge-on galaxies from our sample. Our large sample is intended to be used for studying scaling relations in the stellar disks and bulges and for estimating parameters of the thick disks in different types of galaxies via the image stacking. In this paper, we present the sample selection procedure and general description of the sample.
- ID:
- ivo://CDS.VizieR/J/A+A/478/353
- Title:
- Structural properties of disk galaxies
- Short Name:
- J/A+A/478/353
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A variety of formation scenarios have been proposed to explain the diversity of properties observed in bulges. Studying their intrinsic shape can help to constrain the dominant mechanisms at the epochs of their assembly. The structural parameters of a magnitude-limited sample of 148 unbarred S0-Sb galaxies were derived in order to study the correlations between bulges and disks, as well as the probability distribution function of the intrinsic equatorial ellipticity of bulges. We present a new fitting algorithm (GASP2D) to perform two-dimensional photometric decomposition of the galaxy surface-brightness distribution. This was assumed to be the sum of the contribution of a bulge and disk component characterized by elliptical and concentric isophotes with constant (but possibly different) ellipticity and position angles. Bulge and disk parameters of the sample galaxies were derived from the J-band images, which were available in the Two Micron All Sky Survey. The probability distribution function of the equatorial ellipticity of the bulges was derived from the distribution of the observed ellipticities of bulges and misalignments between bulges and disks.
- ID:
- ivo://CDS.VizieR/J/MNRAS/478/4657
- Title:
- Structural properties of faint LSB galaxies
- Short Name:
- J/MNRAS/478/4657
- Date:
- 10 Dec 2021 13:47:50
- Publisher:
- CDS
- Description:
- We study the structural properties of Low-Surface-Brightness galaxies (LSB) using a sample of 263 galaxies observed by the Green Bank Telescope. We perform 2D decompositions of these galaxies in the Sloan Digital Sky Survey g, r, and i bands using the GALFIT software. Our decomposition reveals that about 60 per cent of these galaxies are bulgeless i.e. their light distributions are well modelled by pure exponential discs. The rest of the galaxies were fitted with two components: a Sersic bulge and an exponential disc. Most of these galaxies have bulge-to-total (B/T) ratio less than 0.1. However, of these 104 galaxies, 20 per cent have B/T>0.1 i.e. hosting significant bulge component and they are more prominent amongst the fainter LSBs. According to g-r colour criteria, most of the LSB galaxies in our sample are blue, with only 7 classified as red LSBs. About 15 per cent of the LSB galaxies (including both blue and red) in our sample host stellar bars. The incidence of bars is more prominent in relatively massive blue LSB galaxies with very high gas fraction. These findings may provide important clues to the formation and evolution of LSB galaxies - in particular on the bar/bulge formation in faint LSB discs.
- ID:
- ivo://CDS.VizieR/J/AJ/129/682
- Title:
- Structural properties of S+S galaxies
- Short Name:
- J/AJ/129/682
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a structural analysis of nearby galaxies in spiral-spiral pairs in optical BVRI bands and compare them with the structures of isolated spiral galaxies and galaxies in ongoing mergers. We use these comparisons to determine how galaxy structure changes during galaxy interactions and mergers. We analyze light concentration (C), asymmetry (A), and clumpiness (S) parameters, and use the projections of CAS parameter space to compare these samples.
- ID:
- ivo://CDS.VizieR/J/MNRAS/423/962
- Title:
- Structure and dynamics of 8 low SB disc galaxies
- Short Name:
- J/MNRAS/423/962
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the radial profiles of the H{alpha}, Mg and Fe line-strength indices for a sample of eight spiral galaxies with a low-surface-brightness stellar disc and a bulge. The correlations between the central values of the line-strength indices and velocity dispersion are consistent with those known for early-type galaxies and bulges of high-surface-brightness galaxies. The age, metallicity and {alpha}/Fe enhancement of the stellar populations in the bulge-dominated region are obtained using stellar population models with variable element abundance ratios.
- ID:
- ivo://CDS.VizieR/J/MNRAS/358/1116
- Title:
- Structure of early-type galaxies
- Short Name:
- J/MNRAS/358/1116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the Photometric Plane (PHP), namely the relation between the effective radius r_e_, the mean surface brightness within that radius {mu}_e_ and the Sersic index n, in optical (R and I) and near-infrared (NIR; K) bands for a large sample of early-type galaxies (ETGs) in the rich cluster MS 1008 at z=0.306.
- ID:
- ivo://CDS.VizieR/J/ApJ/899/89
- Title:
- Structure of 1263 galaxies in Stripe 82 region
- Short Name:
- J/ApJ/899/89
- Date:
- 07 Mar 2022 13:26:50
- Publisher:
- CDS
- Description:
- Establishing a correlation (or lack thereof) between the bimodal color distribution of galaxies and their structural parameters is crucial to understand the origin of bimodality. To achieve that, we have performed a 2D mass-based structural decomposition (bulge+disk) of all disk galaxies (total=1263) in the Herschel imaging area of the Stripe 82 region using Ks-band images from the VICS82 survey. The scaling relations thus derived are found to reflect the internal kinematics and are employed in combination to select an indubitable set of classical- and pseudo-bulge-hosting disk galaxies. The rest of the galaxies (<20%) are marked as disks with "ambiguous" bulges. Pseudo- and classical bulge-disk galaxies exhibit clear bimodality in terms of all stellar parameters (M*, specific star formation rate, r-Ks). All pseudo- bulge-disk galaxies are blue and star forming, and all classical bulge-disk galaxies are red and quiescent with less than 5% digressions. Ambiguous bulge- disk galaxies are intermediate to pseudo- and classical bulge-disk galaxies in the distribution of all structural and stellar parameters. {Delta}<{mu}_eb_>-based on the placement of bulges on the Kormendy relation-is found to be the most efficient single structural indicator of both bulge type and stellar activity. The placement of ambiguous bulge-disk galaxies on scaling relations and the fundamental plane, in addition to their peculiar stellar properties, suggests that they are dominantly part of the green valley.
- ID:
- ivo://CDS.VizieR/J/ApJ/889/80
- Title:
- STUDIES. III. SCUBA-2 450um gal. with MIPS & VLA obs.
- Short Name:
- J/ApJ/889/80
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- We construct a SCUBA-2 450{mu}m map in the COSMOS field that covers an area of 300arcmin^2^ and reaches a 1{sigma} noise level of 0.65mJy in the deepest region. We extract 256 sources detected at 450{mu}m with signal-to-noise ratios >4.0 and analyze the physical properties of their multiwavelength counterparts. We find that most of the sources are at z<~3, with a median of z=1.79_-0.15_^+0.03^%. About 35_-25_^+32^% of our sources are classified as starburst galaxies based on their total star formation rates (SFRs) and stellar masses (M_*_). By fitting the far-infrared spectral energy distributions, we find that our 450{mu}m selected sample has a wide range of dust temperatures (20K<~T_d_<~60K), with a median of T_d_=38.3_-0.9_^+0.4^K. We do not find a redshift evolution in dust temperature for sources with L_IR_>10^12^L_{sun}_ at z<3. However, we find a moderate correlation where the dust temperature increases with the deviation from the SFR-M_*_ relation. The increase in dust temperature also correlates with optical morphology, which is consistent with merger-triggered starbursts in submillimeter galaxies. Our galaxies do not show the tight IRX-{beta}_UV_ correlation that has been observed in the local universe. We construct the infrared luminosity functions of our 450{mu}m sources and measure their comoving SFR densities (SFRDs). The contribution of the L_IR_>10^12^L_{sun}_ population to the SFRD rises dramatically from z=0 to 2 ({propto}(1+z)^3.9+/-1.1^) and dominates the total SFRD at z>~2.