Discovery of a large intergalactic H I cloud in the M 96 group.
Abstract
The discovery of an intergalactic H I cloud, found in the western part of the Leo group of galaxies using the Arecibo 21 cm system is reported. The cloud has a systemic radial velocity of aobut 960 km/sec. The emission is found mainly in a region approximately 100 kpc long by 30 kpc wide midway between M96 and M105. Fainter emission, extending north and south of the cloud, spans about 200 kpc and reaches the vicinity of M96. The nominal H I mass of the whole cloud is about one billion solar masses. However, because of the low rate of collisional excitation, M(H I) may be substantially underestimated for this cloud, and for other H I clouds of very large extent and low density. The velocity structure of the cloud gives an indicative gravitational mass of at least 2 X 10 to the 10th solar masses.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1983
- DOI:
- 10.1086/184118
- Bibcode:
- 1983ApJ...273L...1S
- Keywords:
-
- Centimeter Waves;
- Extragalactic Radio Sources;
- Hydrogen Clouds;
- Intergalactic Media;
- Neutral Gases;
- H Lines;
- Mass Distribution;
- Radial Velocity;
- Radiative Transfer;
- Astronomy