- 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.
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- 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/AJ/136/773
- Title:
- Structure of classical bulges and pseudobulges
- Short Name:
- J/AJ/136/773
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we study the properties of pseudobulges (bulges that appear similar to disk galaxies) and classical bulges (bulges which appear similar to E-type galaxies) in bulge-disk decompositions. We show that the distribution of bulge Sersic indices, n_b_, is bimodal, and this bimodality correlates with the morphology of the bulge. Pseudobulges have n_b_~<2 and classical bulges have n_b_>~2 with little to no overlap. Also, pseudobulges do not follow the correlations of Sersic index with structural parameters or the photometric projections of the fundamental plane in the same way that classical bulges and elliptical galaxies do. We find that pseudobulges are systematically flatter than classical bulges and thus more disk-like in both their morphology and shape.
- 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/702/1567
- Title:
- Structure of 2MASS edge-on galaxies
- Short Name:
- J/ApJ/702/1567
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of an analysis of the J, H, and Ks Two Micron All Sky Survey (2MASS) images of 139 spiral edge-on galaxies selected from the Revised Flat Galaxies Catalog. The basic structural parameters scale length (h), scale height (z_0_), and central surface brightness of the stellar disks ({mu}_0_) are determined for all selected galaxies in the near-infrared (NIR) bands. The mean relative ratios of the scale heights of the thin stellar disks in the J:H:Ks bands are 1.16:1.08:1.00, respectively. Comparing the scale heights obtained from the NIR bands for the same objects, we estimate the scale heights of the thin stellar disks corrected for the internal extinction. We find that the extinction-corrected scale height is, on average, 11% smaller than that in the K band. Using the extinction-corrected structural parameters, we find that the dark-to-luminous mass ratio is, on average, 1.3 for the galaxies in our sample within the framework of a simplified galactic model. The relative thicknesses of the stellar disks z_0_/h correlates with their face-on central surface brightnesses obtained from the 2MASS images. We also find that the scale height of the stellar disks shows no systematic growth with radius in most of our galaxies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/369/1131
- Title:
- Structures in the GA region
- Short Name:
- J/MNRAS/369/1131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To further our understanding of the Great Attractor (GA), we have undertaken a redshift survey using the 2dF on the AAT. Clusters and filaments in the GA region were targeted with 25 separate pointings resulting in approximately 2600 new redshifts. Targets included poorly studied X-ray clusters from the CIZA catalogue as well as the Cen-Crux and PKS 1343-601 clusters, both of which lie close to the classic GA centre. For nine clusters in the region, we report velocity distributions as well as virial and projected mass estimates. The virial mass of CIZA J1324.75736, now identified as a separate structure from the Cen-Crux cluster, is found to be ~3x10^14^M_{sun}_ in good agreement with the X-ray inferred mass. In the PKS 1343-601 field, five redshifts are measured of which four are new. An analysis of redshifts from this survey, in combination with those from the literature, reveals the dominant structure in the GA region to be a large filament, which appears to extend from Abell S0639 (l=281{deg}, b=+11{deg}) to (l~5{deg}, b~-50{deg}), encompassing the Cen-Crux, CIZA J1324.75736, Norma and Pavo II clusters. Behind the Norma Cluster at cz~15000km/s, the masses of four rich clusters are calculated. These clusters (Triangulum-Australis, Ara, CIZA J1514.64558 and CIZA J1410.44246) may contribute to a continued large- scale flow beyond the GA. The results of these observations will be incorporated into a subsequent analysis of the GA flow.
- 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.
