Accreting neutron stars in highly compact binary systems and the nature of 3U 1626--67

Journal Article · Sat Apr 15 04:00:00 EST 1978 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/156068· OSTI ID:6931994

Joss, P C; Avni, Y; Rappaport, S

We discuss the existence of pulsing X-ray sources that consist of neutron stars in highly compact binary systems (orbital periods < or approx. =0./sup d/3), undergoing accretion from low-mass late-type dwarf or degenerate-dwarf companions. An appropriate mass transfer rate can be driven by the decay of the orbit due to gravitational radiation, a self-excited wind, and/or the evolution of the companion. Such a system may result from the evolution of a cataclysmic variable, wherein a degenerate dwarf collapses to form a neutron star after accreting sufficient mass to exceed the Chandrasekhar limit. We apply this model to the 7./sup s/7 S-ray pulsar 3U 1626--67, and demonstrate that it can explain the apparent lack of Doppler shifts in the X-ray pulsations from this source. The model may also account for other observed properties of the source, including (1) the apparent faintness and large ultraviolet excess of the optical counterpart, (2) the lack of X-ray eclipses, and (3) a approx.10/sup 3/ s quasi-periodic oscillation in the source intensity that was recently observed with the SAS 3 satellite.

• Research Organization: Department of Physics and Center for Space Research, Massachusetts Institute of Technology
• OSTI ID: 6931994
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 221:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics &amp; Cosmology-- Quasi-Stellar
Radio
&amp; X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
DWARF STARS
GRAVITATIONAL RADIATION
MATHEMATICAL MODELS
NEUTRON STARS
PULSARS
PULSATIONS
RADIATIONS
STAR ACCRETION
STAR EVOLUTION
STAR MODELS
STARS
STELLAR WINDS