Limits on the Galactic and Cosmic Ionizing Fluxes from Measurements of H alpha Emission from the High-Velocity Neutral Hydrogen Clouds
Abstract
An H-alpha surface brightness of 30 mR has been measured at two positions on high-velocity neutral hydrogen cloud complex C. The measured value limits the emergent Galactic ionizing flux in the Galactic halo, and the cosmic ionizing flux, to less than 60,000 photons/sq cm per sec.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1989
- DOI:
- 10.1086/185555
- Bibcode:
- 1989ApJ...345L..71S
- Keywords:
-
- Galactic Radiation;
- Hydrogen Clouds;
- Interstellar Matter;
- Ionizing Radiation;
- Relic Radiation;
- H Alpha Line;
- Halos;
- Ionization;
- Milky Way Galaxy;
- Astrophysics;
- COSMIC BACKGROUND RADIATION;
- INTERSTELLAR: MATTER