A broad-band view of nearest disc-like ULX
Abstract
Recent work has shown that ultraluminous X-ray sources (ULXs) withluminosities <3*10^39 erg s-1 predominantly show very broad, disc-likespectra. However, little is known of the physics of this spectrum, andhow it relates to both sub-Eddington discs and the brighter ultraluminousstate spectra. Here, we propose 3 simultaneous XMM-Newton and NuSTARobservations of the archetypal, very nearby disc-like ULX M33 X-8,with the goal of resolving the origin of its disc-like spectrum usingbroad-band X-ray spectroscopy. The combination of XMM-Newton and NuSTARwill determine whether the hard tail of the spectrum is thermal ornon-thermal; and with high signal-to-noise EPIC data it will measure thespectral variability between epochs, constraining the plausible physicalmodels for disc-like ULXs.
- Publication:
-
XMM-Newton Proposal
- Pub Date:
- October 2014
- Bibcode:
- 2014xmm..prop..142L