Observing Aql X-1 to understand the hard X-ray emission from NS transients
Abstract
At low luminosities, the X-ray spectra of neutron star (NS) LMXB transients often contain two components: one is due to thermal emission from the NS surface and is reasonably well-understood, while the other is a hard power-law of unknown origin. Recently, observations of Cen X-4 in quiescence with XMM-Newton and the Nuclear Spectroscopic Telescope Array (NuSTAR) have provided the first look at the broadband spectrum. The hard component is sharply cutoff above 10 keV and is consistent with a bremsstrahlung emission mechanism. We propose a joint XMM-Newton, NuSTAR, and Swift Target of Opportunity program to observe Aql X-1 in order to compare the broadband spectrum from this system to that of Cen X-4.
- Publication:
-
XMM-Newton Proposal
- Pub Date:
- October 2013
- Bibcode:
- 2013xmm..prop..126T
- Keywords:
-
- White Dwarf Binaries;
- Neutron Star Binaries;
- Cataclysmic Variables;
- ULXs;
- Black Holes;
- Aql X-1