Spatial Distribution of Pair Production Over the Pulsar Polar Cap
Abstract
Using an analytic, axisymmetric approach that includes general relativity, coupled to a condition for pair production deduced from simulations, we derive general results about the spatial distribution of pair-producing field lines over the pulsar polar cap. In particular, we show that pair production on magnetic field lines operates over only a fraction of the polar cap for an aligned rotator for general magnetic field configurations, assuming the magnetic field varies spatially on a scale that is larger than the size of the polar cap. We compare our result to force-free simulations of a pulsar with a dipole surface field and find excellent agreement. Our work has implications for first-principles simulations of pulsar magnetospheres and for explaining observations of pulsed radio and high-energy emission.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2016
- DOI:
- arXiv:
- arXiv:1604.05670
- Bibcode:
- 2016ApJ...830..119B
- Keywords:
-
- magnetic fields;
- plasmas;
- pulsars: general;
- relativistic processes;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 11 pages, 2 figures. Accepted to ApJ