Simultaneous X-ray and optical observations of the 7.7 second 5> X-ray pulsar 4U 1626-67.
Abstract
Simultaneous X-ray and optical observations of the 7.7-s X-ray pulsar 4U 1626-67, obtained during May 29-31, 1978, reveal the presence of (1) intense, correlated optical and X-ray flares and (2) 7.7-s optical pulsations which agree in phase with the 1-3 keV X-ray pulsations to within 0.5 s (two standard deviations) and which agree in period to within 0.001 s (one standard deviation). From these data it is concluded that a substantial fraction (a minimum of 8%) and possibly all of the optical emission is produced from within approximately 0.5 light sec or 1.5 x 10 to the 10th cm of the neutron star. Furthermore, the data rule out the possibility that this optical emission comes from the X-ray heated surface of a degenerate or nondegenerate dwarf companion. It most likely comes from an accretion disk.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1980
- DOI:
- 10.1086/183163
- Bibcode:
- 1980ApJ...235L..81M
- Keywords:
-
- Pulsars;
- Visual Observation;
- X Ray Astronomy;
- X Ray Stars;
- Flares;
- Light Emission;
- Neutron Stars;
- Astronomy