Abstract
ABSTRACT This paper considers the physical structure and the distribution of gas in the Galaxy, with particular attention given to the galactic distribution of the interstellar atomic and molecular hydrogen. These two components, which contain essentially all of the interstellar gas by mass, are distributed in a thin disk in which both the total gas surface density and the ratio of molecular to atomic hydrogen decrease more or less monotonically with distance from the center of the Galaxy. The molecular hydrogen is concentrated in large (up to a million solar masses) clouds in which star formation is taking place. Due to mass loss from evolving stars, about 20 percent of gas is returned to the interstellar medium. The scale height of the interstellar molecular hydrogen is about half that of the atomic gas.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
