Abstract for Proposal 087199

Studying Black Hole Binaries during their outburst from radio to X-rays

During their outbursts Black Holes Binaries (BHB) can pass through two main spectral states defined by the shape of their X-rays spectra, the hard state and the soft state. The simple assumption is that the spectral and temporal changes are due to modification of the mass accretion rate, but the picture is more complex and another parameter is required to explain behavior of these objects. In order to understand connections between jets and the accretion flow and the nature of physicals processes that occur in BHB, we propose two simultaneous ToO observations with INTEGRAL and XMM, one for each spectral states.



Details on Observing Strategy and Trigger Criteria
A source with a photon index less than 2 and a flux higher than 100 mCrab in the IBIS 30-50 keV band, Swift/BAT 15-50 keV band or in the MAX/GSC 2-20 keV band will be our trigger criteria for the first observation in the hard state. The second observation will be triggered once the source passed in HSS determined by a) an Atel, b) a significant softening of the photon index in the spectral shape (Γ > 2.5), c) a significant variation of the hardness ratio (≃ 25% change between the 3–12 and 30–80 keV bands, i.e., in JEM-X/XRT or ISGRI/BAT). The two XMM observations of 10 ks each will be distributed simultaneously on each INTEGRAL observation.