Abstract for Proposal 090137
Fast multi-lambda variability from a BH: speed, size and geometry of a jet
Correlated multi-lambda variability is a powerful tool for studying the
physics of accretion and ejection in X-ray binaries. Using simultaneous
X-ray and IR data we secured the first unambiguous detection of
sub-second IR variability from a jet, allowing us to estimate the
jet speed and size. Further data yielded the first IR detections of
various quasi-periodic oscillations (types B and C), showing how the
jet properties depend on the spectral state. We propose to monitor the
evolution of a BH outburst with XMM, simultaneously with ground-based
facilities, to apply this technique to multiple states. We ask to perform
20 short XMM observations (7 ks each) to cover the different outburst
stages. We will track energetic and geometrical changes in the jet,
and its relation with the inflow.
Details on Observing Strategy and Trigger Criteria
We will activate our program as soon as a (known or new) BH is reported
in outburst by any ground- or space-based facility, including MAXI,
Swift, NuSTAR, XMM itself. Reaction time: as we aim at monitoring the
full outburst, we do not require fast reaction time. We can do with
observations scheduled one week or more after the trigger, depending
on the XMM schedule complexity and/or on night time at ground-based
facilities. Observing strategy: we are very flexible on this as well.
We will agree on a provisional strategy upon trigger, and we will then
follow closely the source evolution and in case modify the strategy
as needed. As for the trigger, we will do this with more than one
week notice.