A very large array survey of neutral hydrogen in Virgo Cluster spirals. 3: Surface density profiles of the gas

Abstract

view Abstract Citations (307) References (53) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Very Large Array Survey of Neutral Hydrogen in Virgo Cluster Spirals. III. Surface Density Profiles of the Gas Cayatte, V. ; Kotanyi, C. ; Balkowski, C. ; van Gorkom, J. H. Abstract In this paper we analyze the radial profiles of the neutral hydrogen surface density distribution of 17 bright spirals in the Virgo Cluster. The profiles were derived from images, which were obtained with the VLA and which have been presented in a previous paper [Cayatte et al,, AJ, 100,604(1990), Paper I]. Although the sample is still small, we can for the first time show, that different galaxies are affected differently by the cluster environment. We make a quantitative estimate of the importance of the different gas removal mechanisms for selected individual galaxies and compare these estimates with the observed H I morphology. In some galaxies ram-pressure stripping has done serious damage to the H I disks, while in other galaxies turbulent viscous stripping and thermal conductivity have caused a mild, but global H I deficiency across the entire disk. For our analysis we divide the galaxies into three groups according to the ratio of H I to optical diameter, a fourth group contains the anemic galaxies. As it turns out a classification according to relative H I diameter helps to elucidate which gas removal processes play a role. Galaxies in different groups have many other properties in common, most importantly the projected distance from the cluster center. A comparison of the radial H I surface density profiles with those of field spirals of the same morphological type shows, that spirals in different groups are affected very differently by the environment. Galaxies with the smallest H I sizes have normal central surface densities and we suggest that these are the galaxies that are currently undergoing ram-pressure sweeping. The galaxies with only slightly smaller than usual H I diameters have a depressed H I surface density across the entire face of the galaxy. This is quite likely due to viscous stripping. One group is only very mildly affected, this could be caused by gravitational effects due to distant encounters. As a byproduct of this study we had to construct a comparison sample of field spirals of different morphological type. In an appendix we present the radial H I profiles for the comparison sample and the mean profile for each morphological type. We find that the ratio of H I to optical diameter and the central surface densities of H I are significantly larger for the later type spirals. Publication: The Astronomical Journal Pub Date: March 1994 DOI: 10.1086/116913 Bibcode: 1994AJ....107.1003C Keywords: Astrophysics; Density Distribution; Gas Flow; Hydrodynamic Ram Effect; Hydrogen; Images; Morphology; Radial Distribution; Spiral Galaxies; Stripping (Distillation); Virgo Galactic Cluster; Viscous Flow; Angular Resolution; Estimates; Numerical Analysis; Quantitative Analysis; Very Large Array (Vla); Astrophysics; GALAXIES: INTERSTELLAR MEDIUM; LOCAL GROUP; GALAXIES: KINEMATICS AND DYNAMICS full text sources ADS | data products SIMBAD (109) NED (107)