Astronomy and Astrophysics – Astrophysics
Scientific paper
Nov 1996
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996a%26as..120c.107d&link_type=abstract
Astronomy and Astrophysics Supplement, v.120, p.107-110
Astronomy and Astrophysics
Astrophysics
12
Gamma Rays: Theory, Pulsars: General, Pulsars: Individual: Psr 0833-45
Scientific paper
We have used Polar Cap (PC) model simulations of γ-ray pulsars to derive light curves and spectra for Nearly Aligned Rotators (NARs), as well as a more general class of Single Polar Cap (SPC) models which do not require that the inclination α<<1. In these models the observed γ-rays are due to emission concentrated around the rim of a single PC, and may exhibit either one or two peaks. The interpeak emission seen in several doubly peaked sources is produced above the PC interior. If α~θ_b_, the half-width of the PC γ-beam, the peak-to-peak phase separation can be as large as ~0.4-0.5. Our simulation assumes the physics of conventional PC models, in which the γ-rays emerge from photon-pair cascades initiated by curvature radiation from accelerated PC electrons. Here we also assume that the acceleration extends up to heights of several radii above the neutron star surface. We find that the combined effects of increased PC radii (by factors >2) and extended acceleration zones solve a major problem with earlier PC models, namely their small beam widths which imply low detection probabilities. We compare our results with observations of the Vela pulsar, for models in which the primary electrons have a uniform surface density over the PC interior with a sharp increase (~3) near the rim. We describe model parameters which reproduce key features of both the Vela light curves and phase-resolved spectra.
Daugherty Joseph K.
Harding Alice K.
No associations
LandOfFree
Gamma ray pulsars: Extended polar CAP cascades from nearly aligned rotators. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Gamma ray pulsars: Extended polar CAP cascades from nearly aligned rotators., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gamma ray pulsars: Extended polar CAP cascades from nearly aligned rotators. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1145694