The amazing X-ray light curve of 2A 0311-22.7.
Abstract
The X-ray light curve of the AM Herculis-type binary 2A 0311-227 is presented. A smooth modulation of the X-ray flux at the orbital period is obtained, along with an eclipse feature that is total for 0.1-0.8 keV photons yet not visible for photons above about 3 keV. This strong and smooth dependence on energy suggests an origin in the obscuration of the X-ray emitting region by a column of accreting gas. Furthermore, very strong quasi-periodic pulsations with a period of about 6 min are found in the soft X-ray light curve. This periodicity is also present in the optical and hard X-ray light curves, and in the circular polarization data. It seems likely that the periodicity arises from a modulation of the mass accretion rate onto the white dwarf, and possible that it originates in pulsations of a disk-magnetosphere boundary.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1981
- DOI:
- 10.1086/158837
- Bibcode:
- 1981ApJ...245..618P
- Keywords:
-
- Eclipsing Binary Stars;
- Light Curve;
- Stellar Radiation;
- White Dwarf Stars;
- X Ray Sources;
- Circular Polarization;
- Earth Magnetosphere;
- Power Spectra;
- Pulsed Radiation;
- Stellar Atmospheres;
- Stellar Luminosity;
- Stellar Mass Accretion;
- Stellar Spectra;
- Astronomy