Gas in globular clusters. III. Time-independent outflow models including photoionization.
Abstract
An attempt is made to place constraints on the quality and quantity of radiation needed to produce gas outflows in a tightly bound globular cluster of 1 million solar masses. The appropriate hydrodynamic equations are formulated in such a way that any UV or X-ray spectrum may be incorporated into model computations. Special care is taken in the treatment of radiative cooling and the balance between radiative and dielectric recombination, on the one hand, and ionization by electron impact and photon absorption, on the other, considering the elements H, He, C, N, O, and Ne. It is assumed that the flows are spherically symmetric, the gas is optically thin, and the gas ejected by stars is thoroughly mixed on a distance scale which is small compared with that of the overall flow; possible interactions of the flow with the halo medium are ignored. Three sequences of time-independent gas-outflow models are computed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1978
- DOI:
- 10.1086/156387
- Bibcode:
- 1978ApJ...224..394V
- Keywords:
-
- Astronomical Models;
- Globular Clusters;
- Interstellar Gas;
- Photoionization;
- Black Body Radiation;
- Electromagnetic Absorption;
- H Alpha Line;
- Hydrodynamic Equations;
- Ionization Cross Sections;
- Maxwell-Boltzmann Density Function;
- Radiative Heat Transfer;
- Ultraviolet Astronomy;
- Velocity Distribution;
- X Ray Spectra;
- Astrophysics;
- Globular Clusters:Interstellar Gas;
- Globular Clusters: Models