The size distribution of interstellar particles.
Abstract
The linear and circular polarizations of infinite dielectric cylinders of the graphite-silicate mixture with a truncated power-law size distribution proposed by Mathis, Rumpl and Nordsieck (1977) as a model of interstellar particles are calculated. Particles above a specified minimum size are assumed to have perfect Davis-Greenstein alignment, and an index of refraction of 1.6 is used. Results are found to be in good agreement with observations of interstellar extinction between 0.1 and 1 micron, the wavelength dependence of linear and circular polarization, and the albedo and phase function of diffuse galactic light between 0.18 and 0.6 microns, for a maximum particle size of 0.28 micron, a minimum particle size of 0.005 micron and a minimum aligned particle size of 0.08 micron. Observations of mass loss in carbon- and oxygen-rich stars are also noted in support of the proposed graphite-silicate composition of the interstellar grain mixture.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1979
- DOI:
- 10.1086/157335
- Bibcode:
- 1979ApJ...232..747M
- Keywords:
-
- Circular Polarization;
- Dielectric Polarization;
- Graphite;
- Interstellar Matter;
- Linear Polarization;
- Mass Distribution;
- Particle Size Distribution;
- Spatial Distribution;
- Carbon;
- Interstellar Extinction;
- Mathematical Models;
- Oxygen;
- Particle Density (Concentration);
- Particle Mass;
- Silicates;
- Stellar Mass Ejection;
- Astrophysics;
- Interstellar Grains:Sizes;
- Interstellar Matter:Polarization