XTE J1550–564: INTEGRAL Observations of a Failed Outburst

摘要: The well-known black hole X-ray binary transient XTE J1550-564 underwent an outburst during the spring of 2003, which was substantially underluminous in comparison to previous periods peak activity that source. In addition, our analysis shows it apparently remained hard spectral state over duration outburst. This is again sharp contrast major outbursts source 1998/1999, exhibited irregular light curve, multiple changes, and collimated outflows. leads us classify as a "failed outburst." We present results study 2003 event, including curves based on observations from both INTEGRAL RXTE. we studied evolution high-energy 3-300 keV continuum spectrum using data obtained with three main instruments INTEGRAL. These spectra are consistent typical low-hard-state thermal Comptonization emission. also consider event context multisource, multievent period-peak luminosity diagram, clear outlier. then possibility due discrete accretion rather than limit-cycle instability. context, apply model fitting derive timescale for viscous propagation disk infer some physical characteristics.