X-ray luminosities from the spin-powered pulsars
Bing Zhang
Alice K. Harding
Abstract
X-ray luminosities from the spin-powered pulsars are estimated within the
framework of the polar cap cascade model and are compared with the
observational data from ROSAT and ASCA. The important improvement of the
polar cap cascade model is that the contributions of the inverse Compton
scattering (ICS) branch emission from the higher generation pairs are
added into the conventional curvature-synchrotron scenario. It is found
that the low-energy tail of these higher generation ICS branches can have
a significant contribution to the non-thermal X-ray emission detectable by
ROSAT and ASCA. The polar-cap-heating-contributed thermal X-ray emission
is also estimated within the framework of Harding-Muslimov (1998)
acceleration model. A combination of both the non-thermal and thermal
components successfully reproduced the observed X-ray luminosities of the
known spin-powered X-ray pulsars. An important prediction of the model is
that the unknown spectral behavior of the most of the millisecond X-ray
pulsars should be of thermal origin.
File translated from TEX by TTH, version 2.32.
On 16 Jul 1999, 09:19.