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The X-ray absorption spectrum of VELA X-1

1990; IOP Publishing; Volume: 361; Linguagem: Inglês

10.1086/169187

1538-4357

F. Haberl, N. E. White,

SAS software applications and methods

view Abstract Citations (62) References (24) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The X-Ray Absorption Spectrum of VELA X-1 Haberl, F. ; White, N. E. Abstract Exosat observations of the massive X-ray binary Vela X-1 are spectrally analyzed. The absorbing column density shows erratic factor of 10 increases up to 5 x 10 to the 23rd H/sq cm that can occur at any orbital phase and last from minutes to many hours. These variations occur on top of a base level of absorption that increases from 3 x 10 to the 22nd H/sq cm to 15 x 10 to the 22nd H/sq cm from orbital phase about 0.2 to 0.85. It is suggested that these changes are due to intermittent formation of a tenuous accretion disk around the neutron star. The X-ray spectra show a low-energy excess above that expected from cold photoelectric absorption. The character of this excess depends on orbital phase and two different modifications to the simple absorption model are required. Publication: The Astrophysical Journal Pub Date: September 1990 DOI: 10.1086/169187 Bibcode: 1990ApJ...361..225H Keywords: Absorption Spectra; Eclipsing Binary Stars; Stellar Spectra; Supergiant Stars; X Ray Binaries; X Ray Spectra; Accretion Disks; Exosat Satellite; Heao 2; Neutron Stars; Stellar Luminosity; Astrophysics; STARS: ACCRETION; STARS: INDIVIDUAL CONSTELLATION NAME: VELA X-1; STARS: NEUTRON; X-RAYS: BINARIES; X-RAYS: SPECTRA full text sources ADS | data products SIMBAD (2)