- 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.
Number of results to display per page
Search Results
- 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/659/1176
- Title:
- Study of bars in 180 spiral galaxies
- Short Name:
- J/ApJ/659/1176
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Critical insights on galaxy evolution stem from the study of bars. With the advent of HST surveys that trace bars in the rest-frame optical out to z~1, it is critical to provide a reference baseline for bars at z~0 in the optical band. We present results on bars at z~0 in the optical and NIR based on 180 spirals from OSUBSGS (Eskridge et al., 2002, Cat. J/ApJS/143/73).
- ID:
- ivo://CDS.VizieR/J/other/ChA+A/34.367
- Title:
- Study of PGC-54-like galaxies
- Short Name:
- J/other/ChA+A/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the improved Peng's method, we have made the image processing and spiral arm fitting of the newly released spiral galactic images of Sloan Digital Sky Survey (SDSS), and obtained the equivalent thicknesses of galactic disks, as well as the tangential angles of spiral arms of 73 spiral galaxies. These physical quantities are very important for future studies on the properties of spiral galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJS/225/11
- Title:
- Subaru-UDGs in the Coma cluster
- Short Name:
- J/ApJS/225/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of ultra-diffuse galaxies (UDGs) in the Coma cluster. UDGs are a subset of low surface brightness (SB) galaxies with very large effective radii defined by van Dokkum et al. (2015ApJ...798L..45V). We surveyed the Subaru data archive for deep Suprime-Cam/Subaru R-band images, and used data covering the 1.7x2.7{deg} region of the Coma cluster. The data are ~1 magnitude deeper than the data of van Dokkum et al. in limiting SB. This paper explains the details of our sample selection procedure. This UDG catalog includes positions, magnitudes, effective radii, mean and central SBs, and colors (when available). Comparisons with previous galaxy catalogs in the literature are performed, and we show that the current catalog is the largest for UDGs. We also discuss that most of the UDGs are members of the Coma cluster, and the major axis of the UDGs tends to align toward the cluster center (radial alignment).
- ID:
- ivo://CDS.VizieR/J/A+A/579/A115
- Title:
- SUDARE-VOICE variability-selection of AGN
- Short Name:
- J/A+A/579/A115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- One of the most peculiar characteristics of active galactic nuclei (AGNs) is their variability over all wavelengths. This property has been used in the past to select AGN samples and is foreseen to be one of the detection techniques applied in future multi-epoch surveys, complementing photometric and spectroscopic methods. In this paper, we aim to construct and characterise an AGN sample using a multi-epoch dataset in the r band from the SUDARE-VOICE survey. Our work makes use of the VST monitoring programme of an area surrounding the Chandra Deep Field South to select variable sources. We use data spanning a six-month period over an area of 2 square degrees, to identify AGN based on their photometric variability. The selected sample includes 175 AGN candidates with magnitude r<23mag. We distinguish different classes of variable sources through their lightcurves, as well as X-ray, spectroscopic, SED, optical, and IR information overlapping with our survey. We find that 12% of the sample (21/175) is represented by supernovae (SN). Of the remaining sources, 4% (6/154) are stars, while 66% (102/154) are likely AGNs based on the available diagnostics. We estimate an upper limit to the contamination of the variability selected AGN sample =~34%, but we point out that restricting the analysis to the sources with available multi-wavelength ancillary information, the purity of our sample is close to 80% (102 AGN out of 128 non-SN sources with multi-wavelength diagnostics). Our work thus confirms the efficiency of the variability selection method, in agreement with our previous work on the COSMOS field. In addition we show that the variability approach is roughly consistent with the infrared selection.
- ID:
- ivo://CDS.VizieR/J/ApJS/75/241
- Title:
- Supergalactic plane redshift survey
- Short Name:
- J/ApJS/75/241
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Redshift measurements, about 1000 of which are new, are presented for 1314 galaxies in a survey toward the apex of the large-scale streaming flow for ellipticals.
- ID:
- ivo://CDS.VizieR/J/A+A/544/A81
- Title:
- Supernovae and their hosts in the SDSS DR8
- Short Name:
- J/A+A/544/A81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the creation of large and well-defined database that combines extensive new measurements and a literature search of 3876 supernovae (SNe) and their 3679 host galaxies located in the sky area covered by the Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8). This database should be much larger than previous ones, and should contain a homogenous set of global parameters of SN hosts, including morphological classifications and measures of nuclear activity. Identification of the host galaxy sample is 91% complete (with 3536 SNe in 3340 hosts), of which the SDSS names of ~1100 anonymous hosts are listed for the first time. The morphological classification is available for 2104 host galaxies, including 73 (56) hosts in interacting (merging) systems. The total sample of host galaxies collects heliocentric redshifts for 3317 (~90%) galaxies. The g-band magnitudes, D_25_, b/a, and PA are available for 2030 hosts of the morphologically classified sample of galaxies. Nuclear activity measures are provided for 1189 host galaxies. We analyze and discuss many selection effects and biases that can significantly affect any future analysis of our sample. The creation of this large database will help to better understand how the different types of SNe are correlated with the properties of the nuclei and global physical parameters of the host galaxies, and minimize possible selection effects and errors that often arise when data are selected from different sources and catalogues.
- ID:
- ivo://CDS.VizieR/J/ApJS/214/19
- Title:
- Suprime-Cam wide-field photometry of Leo A
- Short Name:
- J/ApJS/214/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have surveyed a complete extent of Leo A --an apparently isolated gas-rich low-mass dwarf irregular galaxy in the Local Group. The B, V, and I passband CCD images (typical seeing ~0.8") were obtained with the Subaru Telescope equipped with the Suprime-Cam mosaic camera. The wide-field (20'x24') photometry catalog of 38856 objects (V~16-26mag) is presented. This survey is also intended to serve as "a finding chart" for future imaging and spectroscopic observation programs of Leo A.
- ID:
- ivo://CDS.VizieR/J/ApJ/763/73
- Title:
- Surface density profiles of GOODS-South galaxies
- Short Name:
- J/ApJ/763/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present stellar mass surface density profiles of a mass-selected sample of 177 galaxies at 0.5<z<2.5, obtained using very deep Hubble Space Telescope optical and near-infrared data over the GOODS-South field, including recent CANDELS data. Accurate stellar mass surface density profiles have been measured for the first time for a complete sample of high-redshift galaxies more massive than 10^10.7^M_{sun}_. The key advantage of this study compared to previous work is that the surface brightness profiles are deconvolved for point-spread function smoothing, allowing accurate measurements of the structure of the galaxies. The surface brightness profiles account for contributions from complex galaxy structures such as rings and faint outer disks. Mass profiles are derived using radial rest-frame ug color profiles and a well-established empirical relation between these colors and the stellar mass-to-light ratio. We derive stellar half-mass radii from the mass profiles, and find that these are on average ~25% smaller than rest-frame g-band half-light radii. This average size difference of 25% is the same at all redshifts, and does not correlate with stellar mass, specific star formation rate, effective surface density, S\'ersic index, or galaxy size. Although on average the difference between half-mass size and half-light size is modest, for approximately 10% of massive galaxies this difference is more than a factor of two. These extreme galaxies are mostly extended, disk-like systems with large central bulges. These results are robust, but could be impacted if the central dust extinction becomes high. ALMA observations can be used to explore this possibility. These results provide added support for galaxy growth scenarios wherein massive galaxies at these epochs grow by accretion onto their outer regions.