On the 2175 Angstrom Absorption Band of Hollow, Onion-like Carbon Particles
Abstract
We present a theoretical result on the ultraviolet absorption of nanoscale graphite onions with a central void. The polarizability and the excitation cross section of particles in this geometry are obtained in the electrostatic (nonretarded) approximation and using a 'spherically uniaxial' dielectric tensor transported from planar graphite. We study the influence of the ratio r/R of the inner and outer radii on the extinction efficiency. It appears that the onion particles for r/R about 0.6 well reproduce the observed UV absorption bump of interstellar dust around 5.7 eV. We also investigate the effects of the hollow structure of the carbon particles on a second absorption peak around 18 eV.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1993
- DOI:
- 10.1086/172422
- Bibcode:
- 1993ApJ...406...92H
- Keywords:
-
- Absorption Cross Sections;
- Fullerenes;
- Graphite;
- Interstellar Extinction;
- Particle Size Distribution;
- Ultraviolet Absorption;
- Absorption Spectra;
- Interstellar Matter;
- Astrophysics;
- ISM: DUST;
- EXTINCTION;
- ISM: MOLECULES