RXTE Monitoring of the Supermassive Star eta Car-- Colliding Wind Emission in a Pre-Hypernova Candidate Binary?
Our detailed RXTE monitoring of the supermassive ``pre-hypernova-candidate'' star eta Carina shows that the X-ray ``low state'' recurs with the optical period of 5.52-years. We interpret this fundamental X-ray variability in terms of a binary model in which the observed variations can mainly be attributed to collisions of 2 extraordinarily powerful stellar winds. However, there are interesting discrepancies between the predictions of simple colliding wind models and the observed behavior of the X-ray emission (in particular, short-term variations, and a decline in the intrinsic source emission during the low state) which need to be explained. Our most recent data shows that ingress into and egress out of the low state is asymmetric, and that the current flux level is somewhat lower than the flux level at the start of the RXTE monitoring.
AAS/High Energy Astrophysics Division #4
- Pub Date:
- April 1999