Simultaneous optical and X-ray burst from 4U MXB 1636-53.
Abstract
Methods of obtaining information about the geometry of X-ray burster systems from simultaneous optical and X-ray observations are discussed, and such simultaneous observations of 4U/MXB 1636-53 are reported. The physical idea of an optical burst being due to reprocessing of an X-ray burst in material in the vicinity of the compact object is discussed. The resulting modification of the X-ray burst signal is described in terms of an optical response function. Delay and smearing due to radiative processes are discussed along with those due to the geometry. For 4U/MXB 1636-53, the estimated delay is 2.5 seconds, the smearing is less than four seconds, and the maximum temperature of the reprocessing region is about 75,000 K. The projected area of the reprocessing region is about 6 x 10 to the 21st square cm. The neutron star is about 1.4 solar masses, the radius of the accretion disk is greater than 1.5 lt-sec, and the mass of the Roche lobe filling companion star is less than 2.0 solar masses, corresponding to a binary period between about one and ten hours.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1982
- DOI:
- 10.1086/160507
- Bibcode:
- 1982ApJ...263..325P
- Keywords:
-
- Binary Stars;
- Bursts;
- Stellar Radiation;
- X Ray Sources;
- Accretion Disks;
- Astronomical Photometry;
- Interstellar Extinction;
- Radiative Transfer;
- Stellar Mass;
- Astrophysics