Nuclear Fusion in Accreting Neutron Stars
Abstract
We note that the total energy release from hydrogen accreting onto a neutron star consists of two entirely distinct contributions: (1) the gravitational potential energy loss by bringing additional mass down to the stellar surface; (2) the energy released in the fusion of the added hydrogen to form helium and heavier nuclei, about 7 MeV per nucleon. The fusion energy source is sufficiently far below the relatively opaque stellar surface that it heats the entire star and the whole surface becomes an X-ray source considerably cooler than the more localized source from contribution 1. These cooler X-rays may persist for many years after accretion is interrupted. We suggest that these notions could be relevant to some X-ray sources, perhaps even to the optical X-ray binary in Hercules. Subject headings: neutron stars - nuclear reactions - X-ray sources
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1973
- DOI:
- 10.1086/152380
- Bibcode:
- 1973ApJ...184..907R