Transition in the X-ray light curve of the AM Herculius system V834 Centauri (E1405-451): 1985-1986 EXOSAT observations

Abstract

view Abstract Citations (7) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Transition in the X-Ray Light Curve of the AM Herculis System V834 Centauri (E1405-451): 1985--1986 EXOSAT Observations Sambruna, Rita M. ; Parmer, Arvind N. ; Chiappetti, Lucio ; Maraschi, Laura ; Treves, Aldo Abstract We analyze the EXOSAT observations of the AM Herculis system V834 Centauri (E1405-451), taken in 1985 March and 1986 August. Archival UV data, simultaneous with the 1986 observations, are also considered. The soft X-ray light curve has a double humped structure, with total eclipse at phi approximately 0.0. It differs significantly from that observed with EXOSAT in 1984. The soft X-ray emission can be described as a black-body of temperature around 10-30 eV, with column density consistent with the interstellar values (5 x 1019- 1.0 x 1020/sq cm). The hard X-ray emission is nearly sinusoidally modulated with a dip at phi approximately 0.0. This component is consistent with thermal bremsstrahlung emission, with rather high column densities (approximately 1022/sq cm. There is indication for absorption variable with orbital phase. At both epochs, evidence for an iron emission feature at approximately 7 keV and with high equivalent widths (approximately 0.8-2 keV) is found. The results are discussed in terms of a scenario of the source suggested by the optical and polarization light curves. Publication: The Astrophysical Journal Pub Date: April 1994 DOI: 10.1086/173944 Bibcode: 1994ApJ...424..947S Keywords: Binary Stars; Iron; Light Curve; Spectrum Analysis; Ultraviolet Astronomy; Ultraviolet Spectra; X Ray Astronomy; X Ray Imagery; Black Body Radiation; Bremsstrahlung; Density (Mass/Volume); Exosat Satellite; Heao 1; Heao 2; Iue; Optical Polarization; Astrophysics; STARS: BINARIES: CLOSE; STARS: INDIVIDUAL CONSTELLATION NAME: V834 CENTAURI; X-RAYS: STARS full text sources ADS | data products SIMBAD (4) MAST (1)