We have derived the galaxy luminosity function (GLF) in the cluster of galaxies Abell 496 from a wide field image in the I band. A single Schechter function reproduces quite well the GLF in the 17<=I_AB_<=22 (-19.5<=M_I_<=eq-14.5) magnitude interval, and the power law index of this function is found to be somewhat steeper in the outer regions than in the inner regions. This result agrees with the idea that faint galaxies are more abundant in the outer regions of clusters, while in the denser inner regions they have partly been accreted by larger galaxies or have been dimmed or even disrupted by tidal interactions.
Catalogue of galaxies towards the Coma Supercluster
Short Name:
VII/159
Date:
21 Oct 2021
Publisher:
CDS
Description:
(Summary of the paper) The existence of a filament of galaxies was shown by Fontanelli (1984) in the Coma cluster region. This paper concerns the study of a IIIaJ Palomar Schmidt plate of the Eastern end of this filament. We have developed a real time reduction technique, quite similar to that used for the COSMOS machine and performed, in real time, an image segmentation. The galaxy selection was made using a classical Bayesian classification based on the diagram of the integrated density versus the area. All the non-stellar objects were thus identified using the PDS and a morphological type was attributed to the galaxies. Our catalogue gives coordinates, magnitudes (derived from the Zwicky et al. (1961-68) and Nilson (1973) catalogues), area in pixels, and morphological types for 7582 galaxies. A histogram of all the galaxy magnitudes shows that the catalogue is apparently complete down to about the 19th magnitude. The asymmetry in the distribution of the bright objects between the North-West and the South-East part of the plate found by Fontanelli (1984) is also present for the fainter objects of our catalogue. We have identified galaxy condensations using an image segmentation on the galaxy density map. The parameters, position, axis, and orientation of these condensations have been estimated.
We present a catalogue of surface-brightness profiles (SBPs) of 125 Galactic globular clusters, the largest such collection ever gathered. The SBPs are constructed from generally inhomogeneous data, but are based heavily on the Berkeley Globular Cluster Survey of Djorgovski & King. All but four of the SBPs have photometric zero points. We derive central surface brightnesses, King-model concentrations, core radii, half-light, and other fraction-of-light radii where data permit, and we briefly discuss their use.
The catalogue describes the position, maximum angular diameters, classifications according to form, structure and brightness, and the number of associated stars. The acronym used in the literature to designate objects from this catalogue is Sh 2 (e.g. Sh 2-1 for the first HII region of the catalogue)
A catalogue is presented of galaxies having large-scale observations in the HI line. This catalogue collects from the literature the information that characterizes the observations in the 21-cm line and the way that these data were presented by means of maps, graphics and tables, for showing the distribution and kinematics of the gas. It contains furthermore a measure of the HI extension that is detected at the level of the maximum sensitivity reached in the observations. This catalogue is intended as a guide for references on the HI maps published in the literature from 1953 to 1995 and is the basis for the analysis of the data presented in Paper II (Cat. <J/A+AS/131/77>).
We use some of the maps of the catalogue presented in Paper I (Cat. <J/A+AS/131/73>) to provide some evidence for global conditions that must be fulfilled by the galaxies to have extended hydrogen. For this purpose, we tried to find possible connections between the HI gas extension and other properties of the galaxies (morphological type, surface brightness, gas density, etc.). With isophotal hydrogen diameters of a large sample, we could observe that optically smaller galaxies seem to have greater relative HI extensions. By means of the relation with the apparent HI surface density, we found an expression that should provide a rough estimate of the gas extension. With respect to the dependence on morphological type, we could not find any significant correlation either for the real HI surface density or the relative gas extension. Nevertheless, whereas for spiral and irregular galaxies the real HI surface density exhibits a broad range of values, the values are rather lower for elliptical and S0 galaxies.
There are given 1064 profiles of the hydrogen lines H{gamma} and H{delta} for 235 B,A,F-stars obtained at the Main Stellar Spectrograph of the 6-m telescope in 1978-1986 in the course of several large observing projects. Optical density close to D=1.0 was reached for all spectra on Kodak IIaO photographic plates. The profiles are presented as smoothed intensity normalized to the level of local continuum for different distances from lines core, in {AA}. The blue and red wings of H{gamma} and H{delta} lines are averaged.
In light of substantial new discoveries of hot subdwarfs by ongoing spectroscopic surveys and the availability of new all-sky data from ground-based photometric surveys and the Gaia mission Data Release 2, we compiled an updated catalogue of the known hot subdwarf stars.
