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Angular Momentum Transfer in the Binary X-ray Pulsar GX 1+4
Citation
Greenhill, JG and Galloway, D and Murray, JR, Angular Momentum Transfer in the Binary X-ray Pulsar GX 1+4, Publications of the Astronomical Society of Australia, 16, (3) pp. 240-246. ISSN 1323-3580 (1999) [Refereed Article]
DOI: doi:10.1071/AS99240
Abstract
: Optical and X-ray spectroscopy indicate that the X-ray pulsar GX 1+4 is seen through a cloud of gravitationally bound matter. We discuss an unstable negative feedback mechanism (originally proposed by Kotani et al. 1999), based on X-ray heating of this matter which controls the accretion rate when the source is in a low X-ray luminosity state. A deep minimum lasting ~ 6 hours occurred during observations with the RXTE satellite over 1996 July 19â€"21. The shape of the X-ray pulses changed remarkably from before to after the minimum. These changes may be related to the transition from neutron star spin-down to spin-up which occurred at about the same time. Smoothed particle hydrodynamic simulations of the effect of adding matter with opposite angular momentum to an existing disk, show that it is possible for a number of concentric rings with alternating senses of rotation to co-exist in a disk. This could provide an explanation for the step-like changes in P which are observed in GX 1+4. Changes at the inner boundary of the disk occur at the same timescale as that imposed at the outer boundary. Reversals of material tornne on the neutron star occur at, a, minimum in TJV. © 1999, Astronomical Society of Australia. All rights reserved.
Item Details
Item Type: | Refereed Article |
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Research Division: | Physical Sciences |
Research Group: | Astronomical and Space Sciences |
Research Field: | Galactic Astronomy |
Objective Division: | Expanding Knowledge |
Objective Group: | Expanding Knowledge |
Objective Field: | Expanding Knowledge in the Physical Sciences |
UTAS Author: | Greenhill, JG (Dr John Greenhill) |
UTAS Author: | Galloway, D (Mr Duncan Galloway) |
ID Code: | 16543 |
Year Published: | 1999 |
Web of Science® Times Cited: | 2 |
Deposited By: | Physics |
Deposited On: | 1999-08-01 |
Last Modified: | 2000-05-20 |
Downloads: | 0 |
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