Polars going bad: EF Eridani in the low state
Abstract
The polar EF Eridani (2A 0311-227) was once one of the brightest soft X-ray sources in the sky. For the past 15 years it has been in an extended inactive state (with the exception of occasional short "burps"). We have been studying the residual activity in this system. The data suggest that the residual optical activity occurs on the surface of the substellar mass companion, or in a coupling region where the secondary's wind and/or its magnetic field interacts with the megaGauss field of the white dwarf. We proposed successfully to obtain XMM observations, which were obtained in January 2011. These data clearly detect the source and a modulation on the orbital period. Analysis will show whether this is due to a surface hot spot, cyclotron emission, the coupling region, or even an active hemisphere on the yet-unseen secondary. This proposal seeks funding to undertake this analysis.
- Publication:
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NASA ADAP Proposal
- Pub Date:
- 2011
- Bibcode:
- 2011adap.prop..124W