The binary pulsar: physical processes, possible companions, and evolutionary histories.
Abstract
Some properties of the binary pulsar PSR 1913+16 are investigated in the light of recently reported observational results. It is shown how an accurate analysis of pulse arrival times and changes in pulse shape can, in principle, yield the masses and orbital inclination of the system as well as the orientation of the pulsar spin axis and information on the variation of pulse shape, spectrum, and polarization over the pulsar surface. Secular changes of the orbital elements induced by an off-axis rotator are analyzed along with relativistic, tidal, and rotational effects which cause the orbit to deviate from a Keplerian ellipse. Four classes of dissipative effects are studied: energy loss by gravitational radiation, mass loss from either the pulsar or its companion, tidal effects, and proper motion. The nature of the companion star is examined, considering a helium star, a white dwarf, a neutron star, and a black hole. It is shown that the system probably consists of two neutron stars of about 1.4 solar masses each, that the most likely progenitor was an X-ray binary which shrank to the required presupernova configuration by becoming a double-core star, and that the supernova occurred about 1 million years ago.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1976
- DOI:
- 10.1086/154524
- Bibcode:
- 1976ApJ...207..574S
- Keywords:
-
- Binary Stars;
- Companion Stars;
- Neutron Stars;
- Pulsars;
- Stellar Evolution;
- Black Holes (Astronomy);
- Orbital Elements;
- Stellar Mass;
- Stellar Motions;
- White Dwarf Stars;
- Astrophysics