Accession Number:
ADA327573
Title:
A Modified Beat Frequency Modulated Accretion Model I. Spin Periods and Magnetic Moments of Z-Sources Inferred from Horizontal Branch QPO.
Descriptive Note:
Technical rept.,
Corporate Author:
STANFORD UNIV CA W W HANSEN LABS OF PHYSICS
Personal Author(s):
Report Date:
1996-01-01
Pagination or Media Count:
35.0
Abstract:
We present a modified beat-frequency modulated accretion model appropriate to a description of the horizontal branch oscillations of Z-type low-mass x-ray binaries. This model incorporates several new physical elements 1 magnetic screening by the accretion disk and neutron star, 2 radiation pressure dominance in the inner disk, and 3 stellar rotation effects. Fitted to observational data, the model constrains the surface magnetic field in a typical LMXB Z source to be less than 10exp 9 G and the stellar spin frequency to be greater than 400 Hz. The predicted high stellar spin frequency falls in a range where observational upper limits on pulsation are not a constraint. The derived magnetic field and spin frequency range are compatible with the fastest radio pulsars.
Descriptors:
Subject Categories:
- Astronomy
- Astrophysics