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

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.

Subject Categories:

  • Astronomy
  • Astrophysics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE