Astrophysics (index)about

gas fraction

(gas mass fraction, baryonic gas fraction)
(fraction of a galaxy or cluster consisting of gas)

Gas fraction (or gas mass fraction or baryonic gas fraction) is the ratio of the mass of baryons in the form of gas in a region such as a galaxy or galaxy cluster to the mass also including stars themselves.

Mgas + Mstars

The term molecular gas fraction is similar, but indicates the gas mass in the numerator is specifically gas in molecular form, i.e., "ready" for star formation.


Referenced by:
gas fraction estimation