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XMM-Newton detection of Nova Muscae 1991 in Quiescence

F. K. Sutaria·U. Kolb·P. A. Charles·J. P. Osborne·E. Kuulkers·J. Casares·E. T. Harlaftis·T. Shahbaz·M. D. Still·P. J. Wheatley
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Abstract

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 $\simeq 1.1 \times 10^{-14}$ ergs cm$^{-2}$ s$^{-1}$. The spectra is well fit by an absorbed powerlaw with a photon index of $ α= 1.6 \pm 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.

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F. K. Sutaria, U. Kolb, P. A. Charles, J. P. Osborne, E. Kuulkers, J. Casares, E. T. Harlaftis, T. Shahbaz, M. D. Still, P. J. Wheatley. 2002-06-07. XMM-Newton detection of Nova Muscae 1991 in Quiescence. https://doi.org/10.1051/0004-6361%3A20020842

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