Pulsar extinction.
Abstract
The radiation properties of pulsars are reinvestigated in the context of the 'PCFB' model, according to which the radiation originates at the polar caps and the magnetic-field lines change from a closed to an open configuration at the 'force-balance' or 'corotation' radius. Major attention is given to the condition for electron-positron pair creation, which leads, in turn, to an extinction condition whereby any pulsar will cease to be a radio emitter after its period has increased beyond a certain value. This extinction condition is derived on the basis of a model where the magnetic field is the same as that of a point dipole located at the center of the star; effects of dipole distortion are also considered. A comparison of the results with observational data shows that most pulsars satisfy or nearly satisfy the pair-creation condition for undistorted dipoles and seem to satisfy the extinction condition. It is noted that pulsars which should be extinguished according to the undistorted-dipole model need not be if the magnetic field is sufficiently distorted at the polar caps.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1976
- DOI:
- 10.1086/154382
- Bibcode:
- 1976ApJ...206..273S
- Keywords:
-
- Magnetic Dipoles;
- Pair Production;
- Polar Caps;
- Pulsars;
- Radio Emission;
- Astronomical Models;
- Electron-Positron Pairs;
- Field Strength;
- Gamma Rays;
- Lines Of Force;
- Magnetospheres;
- Astrophysics