Supergalactic studies. II - Supergalactic distribution of the nearest intergalactic gas clouds

Abstract

view Abstract Citations (22) References (20) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Supergalactic studies. II. Supergalactic distribution of the nearest intergalactic gas clouds. de Vaucouleurs, G. ; Corwin, H. G., Jr. Abstract It is shown that the nearby 'high-velocity' H I clouds, including the Magellanic Stream, are strongly concentrated toward the equator of the Local Cloud of galaxies, which is inclined 14 deg to the main supergalactic plane. Supergalactic concentration indices are determined for the centroids, intensity maxima, or both, of all major high-velocity H I clouds for which sufficient information is available. Calculations are then made for the cumulative Poisson distribution probabilities that the observed supergalactic concentration could have arisen by chance in the hypothesis of statistical isotropy. It is found that the observed concentration is significant at the 99.9% confidence level and that most of the high-velocity clouds are truly intergalactic, being associated with the Local Group and nearer groups of galaxies. The space density of the intergalactic gas clouds is estimated as 20 to 25 per cu Mpc, in approximate agreement with the densities required by the collision theory of ring galaxies. Publication: The Astrophysical Journal Pub Date: December 1975 DOI: 10.1086/153980 Bibcode: 1975ApJ...202..327D Keywords: Galactic Clusters; Hydrogen Clouds; Intergalactic Media; Magellanic Clouds; Galactic Structure; Hydrogen Atoms; Mass Distribution; Nebulae; Poisson Density Functions; Ring Galaxies; Space Density; Star Distribution; Astronomy full text sources ADS | data products NED (2)