We explore the internal structure of red-sequence galaxies in the Coma cluster across a wide range of luminosities (-17>M_g_>-22) and cluster-centric radii (0<r_cluster_<1.3r_200_). We present the 2D bulge-disc decomposition of galaxies in deep Canada-France-Hawaii Telescope u, g, i imaging using GALFIT. Rigorous filtering is applied to identify an analysis sample of 200 galaxies which are well described by an 'archetypal' S0 structure (central bulge + outer disc).
We perform two-dimensional, point-spread-function-convolved, bulge+disk decompositions in the g and r bandpasses on a sample of 1123718 galaxies from the Legacy area of the Sloan Digital Sky Survey Data Release Seven. Four different decomposition procedures are investigated which make improvements to sky background determinations and object deblending over the standard SDSS procedures that lead to more robust structural parameters and integrated galaxy magnitudes and colors, especially in crowded environments. We use a set of science-based quality assurance metrics, namely, the disk luminosity-size relation, the galaxy color-magnitude diagram, and the galaxy central (fiber) colors to show the robustness of our structural parameters. The best procedure utilizes simultaneous, two-bandpass decompositions. Bulge and disk photometric errors remain below 0.1mag down to bulge and disk magnitudes of g~19 and r~18.5. We also use and compare three different galaxy fitting models: a pure Sersic model, an n_b_=4 bulge+disk model, and a Sersic (free n_b_) bulge+disk model. The most appropriate model for a given galaxy is determined by the F-test probability. All three catalogs of measured structural parameters, rest-frame magnitudes, and colors are publicly released here.
We investigate scaling relations of bulges using bulge-disk decompositions at 3.6um and present bulge classifications for 173 E-Sd galaxies within 20Mpc. Pseudobulges and classical bulges are identified using Sersic index, Hubble Space Telescope morphology, and star formation activity (traced by 8um emission). In the near-IR pseudobulges have n_b_<2 and classical bulges have n_b_>2, as found in the optical. Sersic index and morphology are essentially equivalent properties for bulge classification purposes. We confirm, using a much more robust sample, that the Sersic index of pseudobulges is uncorrelated with other bulge structural properties, unlike for classical bulges and elliptical galaxies. Also, the half-light radius of pseudobulges is not correlated with any other bulge property. We also find a new correlation between surface brightness and pseudobulge luminosity; pseudobulges become more luminous as they become more dense.
We present deep wide-field VI CCD photometry of the Sextans dwarf spheroidal galaxy (dSph) in the Local Group, covering a field of 42'x28' located at the center of the galaxy (supplemented by short B photometry). The limiting magnitudes with 50% completeness are V=24.4mag and I=23.6mag.
We present BVIc photometry of the brightest stars and compact star clusters in NGC 2976, a dwarf galaxy in the interacting M81/M82 group. Deep CCD images of the galaxy were obtained with the 6m-Telescope of the Special Astrophysical Observatory (Russia) at arcsec resolution. About 290 young stars and concentrated young clusters were measured. Supplementaxy data in the ultraviolet are taken from the literature. The extinction to the measured objects is comparatively low, E(B-V)~0.15-0.20mag. We estimate the ages of youngest resolved stars and concentrated star clusters to be ~5x10^6^years. This population is concentrated in a broad stripe facing M81. In the central disk the population is a bit older, about 8x10^6^years, this may be a hint to an outward spreading star formation process. The metallicity of the disk population is estimated as solar (z~0.02) from a fitting to Padova theoretical stellar isochrones.
We present B, V and I CCD stellar photometry for a sample of 20 field irregular dwarf galaxies. Their corrected radial velocity is V_0_<500km/s. Most of them have been resolved into stars for the first time. Based on photometry of their brightest blue stars we have derived the following distances: 5.9Mpc (UGC 685), 5.4Mpc (UGC 1281), 7.2Mpc (UGC 3303), 7.0Mpc (UGC 3476), 7.3:Mpc (UGC 3600), 7.2:Mpc (UGC 3698), 7.9Mpc (NGC 2337), 8.6Mpc (UGC 3817), 5.7Mpc (UGC 3860), 5.6Mpc (UGC 4426), >=7.9Mpc (F 565-v1), 7.4:Mpc (UGC 5086), 7.1Mpc (UGC 5272), 5.9Mpc (UGC 5340), 7.1Mpc (UGC 5427), 2.7:Mpc (UGC 5456), 6.6Mpc (NGC 3274), 9.3Mpc (UGC 5889), 5.2Mpc (NGC 5238), and 8.0Mpc (UGC 9405). Our sample exhibits diverse morphological properties evidently caused by their different starburst activity. The galaxy sample has a median integral absolute magnitude M_B_=-14.6 and a median integral colour (B-V)_T_=+0.47. One dwarf, UGC 5340, stands out by its very blue colour, (B-V)_T_=+0.18, and by its high M(HI)/L ratio, as expected for young galaxies. Four objects of the sample are IRAS sources. Being well isolated systems, the considered galaxies may be used to estimate a local value of the Hubble parameter, H=V_0_/D. For half of the sample galaxies their individual H- values are concentrated within [58-68]km/s/Mpc with a median of 65km/s/Mpc.
We present high-resolution HST imaging in the optical (WFPC2) and near-infrared (NICMOS) of a disk region 1kpc northeast of the starburst core in the nearby galaxy M82.
BVI phot. of CFRS 0300+00 & 1415+52 fields galaxies
Short Name:
J/A+A/435/507
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog contains 75 field galaxies in two 10'x10' CFRS fields 0300+00 and 1415+52 with HST/WFPC2 image and deep ISOCAM observations. They are not detected in the ISO observations to a detection limit of 300{mu}Jy at 5{sigma} level. Magnitudes and Structural parameters in three HST bands and according morphological classification are presented
We study the photometric and structural properties of the star cluster system in the late type Sc spiral NGC 3370. BVI observations from the Advanced Camera for Surveys on board of HST are used to analyse in detail the colours, magnitudes and spatial properties of cluster candidates. The final catalogue of sources used for the study is composed by 277 objects.
We present BVI photometry of 190 galaxies in the central 4x3deg^2^ region of the Fornax cluster observed with the Michigan Curtis Schmidt Telescope. Results from the Fornax Cluster Spectroscopic Survey (FCSS) and the Flair-II Fornax Surveys have been used to confirm the membership status of galaxies in the Fornax Cluster Catalogue (FCC, Cat. <VII/180>). In our catalogue of 213 member galaxies, 92 (43 per cent) have confirmed radial velocities.