Star Formation via the Phase Transition of an Adiabatic Gas
Abstract
An analytic model based on a second-order accurate global virial analysis is used to describe two stable equilibrium states for rotating gas clouds - a pressure-supported, diffuse state and a rotationally supported, compact state. Equilibrium sequences are constructed for clouds obeying an adiabatic equation of state, and analytic expressions for extrema along the sequences are derived. The physical relationship between diffuse and compact equilibria is illustrated. An energy barrier generally separates the two states, but nonequilibrium processes can induce a transformation from the diffuse to the compact state, hence induce star formation. The authors suggest that fluctuations in the interstellar medium of some galaxies may actually cause star formation to proceed primarily via a phase transition, rather than via the classical Jeans instability.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1988
- DOI:
- 10.1086/166041
- Bibcode:
- 1988ApJ...325..699T
- Keywords:
-
- Adiabatic Conditions;
- Interstellar Gas;
- Phase Transformations;
- Star Formation;
- Stellar Models;
- H I Regions;
- Molecular Clouds;
- Rotating Plasmas;
- Virial Theorem;
- Astrophysics;
- HYDRODYNAMICS;
- STARS: FORMATION