Cosmic-Ray Penetration Into Molecular Clouds
Abstract
Assuming dense interstellar clouds to be threaded by the general galactic magnetic field, the role of magnetic fields in reducing the interior cosmic ray intensity was investigated. The diffusive effects of small scale irregularities inside and outside the cloud, and of large scale hydromagnetic waves, were found to be negligible down to energies of some tens of MeV/nucleon; therefore, quasistatic magnetic mirrors which may arise at local condensations and trap particles over time scales long enough so that the trapped cosmic ray population is absent due to losses. This energy independent effect can lead to an average reduction of gamma-ray luminosity and hydrogen ionization rate of about 50%. At the same time density contrasts in the gas are considerably emphasized in the gamma-light.
- Publication:
-
Recent Advances in Gamma-Ray Astronomy
- Pub Date:
- July 1977
- Bibcode:
- 1977ESASP.124..153C
- Keywords:
-
- Cosmic Rays;
- Interstellar Gas;
- Molecular Gases;
- Diffuse Radiation;
- Gamma Rays;
- Hydrogen Clouds;
- Hydrogen Ions;
- Interstellar Magnetic Fields;
- Ion Production Rates;
- Magnetic Mirrors;
- Magnetohydrodynamic Waves;
- Trapped Particles;
- Space Radiation