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Title: H I extent and deficiency of spiral galaxies in the Virgo cluster

Abstract

Neutral hydrogen observations mapping along the optical major axis have been made with the Arecibo 305-m telescope and flat feed system for 24 spiral galaxies in the Virgo cluster. Comparison of observed flux integrals with those obtained from a numerical convolution of the antenna beam pattern and an assumed H I surface density distribution yields a measure of an effective H I size, taken to be that radius interior to which lies 70% of the total H I mass. The neutral hydrogen properties of the Virgo cluster spirals have been compared with those of a similar sample of isolated galaxies. We find that, for a given optical diameter, a Virgo core galaxy has a smaller H I extent than its optical counterpart; we measure the ratio of the H I to optical Holmberg diameter d/sub Htsi//d/sub Ho/ to be 0.70 for the 19 galaxies within a five degree projected radius of the cluster center, whereas those outside show d/sub Htsi//d/sub Ho/ approx. =1.10. Using the relation derived between the optical linear diameter and the H I mass, we are able to define a H I deficiency parameter and find that the galaxies in the Virgo core are, on the average,more » H I deficient by a factor of 2.7 with respect to the isolated galaxies. The similarity of the relationship between the H I mass and the H I linear diameter, within the statistical errors, for both gas deficient and normal galaxies, implies that the linear extent of the H I distribution within a galaxy is well correlated with its total H I mass. The stripping mechanisms responsible for the H I deficiency observed in cluster galaxies, therefore, do not substantially alter the average H I surface density, but rather lower the H I mass and size to values expected for an optically smaller galaxy. The dependence of the H I deficiency on the velocity of a galaxy with respect to the cluster suggests that the mechanism responsible for the removal of the interstellar gas from the galaxy is the ram pressure sweeping of the intracluster gas.« less

Authors:
;
Publication Date:
Research Org.:
Arecibo Observatory, Arecibo, Puerto Rico 00613
OSTI Identifier:
5984198
Resource Type:
Journal Article
Journal Name:
Astron. J.; (United States)
Additional Journal Information:
Journal Volume: 88:7
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; GALAXIES; H1 REGIONS; GALAXY CLUSTERS; SPATIAL DISTRIBUTION; GHZ RANGE 01-100; SPIRAL CONFIGURATION; CONFIGURATION; COSMIC RADIO SOURCES; DISTRIBUTION; FREQUENCY RANGE; GHZ RANGE; 640103* - Astrophysics & Cosmology- Quasi-Stellar, Radio, & X-Ray Sources- (-1987); 640105 - Astrophysics & Cosmology- Galaxies

Citation Formats

Giovanelli, R, and Haynes, M P. H I extent and deficiency of spiral galaxies in the Virgo cluster. United States: N. p., 1983. Web. doi:10.1086/113376.
Giovanelli, R, & Haynes, M P. H I extent and deficiency of spiral galaxies in the Virgo cluster. United States. https://doi.org/10.1086/113376
Giovanelli, R, and Haynes, M P. 1983. "H I extent and deficiency of spiral galaxies in the Virgo cluster". United States. https://doi.org/10.1086/113376.
@article{osti_5984198,
title = {H I extent and deficiency of spiral galaxies in the Virgo cluster},
author = {Giovanelli, R and Haynes, M P},
abstractNote = {Neutral hydrogen observations mapping along the optical major axis have been made with the Arecibo 305-m telescope and flat feed system for 24 spiral galaxies in the Virgo cluster. Comparison of observed flux integrals with those obtained from a numerical convolution of the antenna beam pattern and an assumed H I surface density distribution yields a measure of an effective H I size, taken to be that radius interior to which lies 70% of the total H I mass. The neutral hydrogen properties of the Virgo cluster spirals have been compared with those of a similar sample of isolated galaxies. We find that, for a given optical diameter, a Virgo core galaxy has a smaller H I extent than its optical counterpart; we measure the ratio of the H I to optical Holmberg diameter d/sub Htsi//d/sub Ho/ to be 0.70 for the 19 galaxies within a five degree projected radius of the cluster center, whereas those outside show d/sub Htsi//d/sub Ho/ approx. =1.10. Using the relation derived between the optical linear diameter and the H I mass, we are able to define a H I deficiency parameter and find that the galaxies in the Virgo core are, on the average, H I deficient by a factor of 2.7 with respect to the isolated galaxies. The similarity of the relationship between the H I mass and the H I linear diameter, within the statistical errors, for both gas deficient and normal galaxies, implies that the linear extent of the H I distribution within a galaxy is well correlated with its total H I mass. The stripping mechanisms responsible for the H I deficiency observed in cluster galaxies, therefore, do not substantially alter the average H I surface density, but rather lower the H I mass and size to values expected for an optically smaller galaxy. The dependence of the H I deficiency on the velocity of a galaxy with respect to the cluster suggests that the mechanism responsible for the removal of the interstellar gas from the galaxy is the ram pressure sweeping of the intracluster gas.},
doi = {10.1086/113376},
url = {https://www.osti.gov/biblio/5984198}, journal = {Astron. J.; (United States)},
number = ,
volume = 88:7,
place = {United States},
year = {Fri Jul 01 00:00:00 EDT 1983},
month = {Fri Jul 01 00:00:00 EDT 1983}
}