Abstract for Proposal 084423
Fast multi-wavelength variability from a BH: speed, size and geometry of a jet
Correlated fast multi-wavelength variability is quickly becoming a key
tool for studying the physics of accretion/ejection of relativistic
jets. Using X-ray/IR simultaneous data we have recently discovered
vibrations from a relativistic jet down to 62.5 ms time scale, which
allowed us to estimate the jet speed and size. Our results from further
data also show that the jet properties depend on the spectral state
of the BH. Here, we propose to monitor the outburst evolution of a BH
transient with XMM, simultaneously with ground-based OIR facilities, in
order to apply the same technique to different states. We will monitor
the energetic and geometrical changes in the jet, and its relation with
the accretion disk. We propose to perform up to 12 short XMM observations.
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 live with observations scheduled
one week or more after the trigger, depending on the XMM schedule
complexity and/or on the VLT Service-Mode nights. Observing strategy:
we are very flexible on this as well. The observing strategy will
depend mostly on the SM nights at VLT. 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.