The X-ray spectrum of the unusual neutron star X-ray binary SAX J2224.9+5421
Abstract
We propose a 50-ks XMM-Newton observation of the unusual neutron star X-ray binary SAX J2224.9+5421. Our target was discovered by BeppoSAX/WFC when it exhibited a thermonuclear X-ray burst. Follow-up observations aiming to constrain the persistent emission were performed ~8 h later and detected the source at a 0.5-10 keV luminosity of ~1E33 erg/s. This is very peculiar since neutron star binaries are generally considered to be in quiescence at luminosities of ~1E31-1E33 erg/s, while they display accretion outbursts with luminosities of ~1E34-1E38 erg/s. With the proposed observation we aim for a detailed investigation of the X-ray spectrum of SAX J2224.9+5421 to find clues explaining its unusual behavior.
- Publication:
-
XMM-Newton Proposal
- Pub Date:
- October 2010
- Bibcode:
- 2010xmm..prop...72D
- Keywords:
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- White Dwarf Binaries;
- Neutron Star Binaries;
- Cataclysmic Variables;
- ULXs;
- Black Holes;
- SAX J2224.9+542