XMM-Newton detection of Nova Muscae 1991 in quiescence

Sutaria, F. K.; Kolb, U.; Charles, P.; Osborne, J. P.; Kuulkers, E.; Casares, J.; Harlaftis, E. T.; Shahbaz, T.; Still, M.; Wheatley, P.
Bibliographical reference

Astronomy and Astrophysics, v.391, p.993-997 (2002)

Advertised on:
9
2002
Number of authors
10
IAC number of authors
1
Citations
17
Refereed citations
16
Description
The soft X-ray transient GU Mus has been detected by XMM-Newton in the quiescent state. The source is very faint, with a 0.5-10.0 keV unabsorbed flux of =~ 1.1 x 10-14 ergs cm-2 s-1. The spectra is well fit by an absorbed powerlaw with a photon index of alpha = 1.6 +/- 0.4, close to the value seen when the source was in the low/hard state in Aug. 1991. From our observed luminosity, it seems unlikely that the quiescent state emission is dominated by coronal X-rays from the secondary. The flux also appears to be in agreement with the ADAF model of BH-transients in quiescence.