The charge distribution on interstellar grains—The effect of induced charge
Abstract
A calculation of the equilibrium charge acquired by interstellar grains is given, which takes account of polarization charges that are induced in a grain by incident ions and electrons. Both metal and dielectric grains are considered and photoionization of the latter grains by UV radiation is taken into account where necessary. It is found that the inclusion of the polarization charges in the calculation is only important in gas clouds where the mean charge on a grain is low (<1e); that is, for H I regions and dense molecular clouds. In such clouds, the effect of the polarization charges is to increase the amount of negative charge acquired by a grain. A discussion is given concerning the validity of the classical electrostatic theory employed in the paper for small grains of radius ≲10-6 cm, and some astrophysical consequences of the modification of the grain charge by polarization effects are considered.
- Publication:
-
Astrophysics and Space Science
- Pub Date:
- December 1978
- DOI:
- 10.1007/BF01023927
- Bibcode:
- 1978Ap&SS..59..389S
- Keywords:
-
- Charge Distribution;
- Charged Particles;
- Cosmic Dust;
- Interstellar Matter;
- Dielectrics;
- Electric Conductors;
- Electrostatics;
- H I Regions;
- Interstellar Chemistry;
- Neutral Particles;
- Particle Collisions;
- Photoelectric Effect;
- Astrophysics