Abstract for Proposal 096396

The first sample of jet properties from accreting black holes and neutron stars

Astrophysical jets are powerful streams of gas and energy that form when matter falls onto compact object, which have a huge impact on their nearby environment. However, there are still key open questions regarding jets are launched or powered. Fast optical/infrared and X-ray variability studies of black hole and neutron star low-mass X-ray binaries (LMXBs) recently opened a new way to constrain the base of the jet, discovering a new rich and exciting phenomenology. Here we propose to perform the first fast X-ray + IR weekly monitoring program of active LMXBs. In detail, we aim to perform 9 strictly simultaneous observations with XMM (9 x 15 ks) and HAWK-I (9 x 1hr) during the summer visibility window. This will allow us to collect the first comparable sample of jet measurements from both systems.



Details on Observing Strategy and Trigger Criteria
We aim to perform a weekly monitoring of the fast-X-ray/IR fast-X-ray/IR variability in LMXBs. Given that almost all LMXB are in the galactic center, we ask to pre-schedule the observations during specific windows, when we know that most of sources will be visible by both observatories. Each week we will decide the best source to observe through a decision tree algorithm: in detail we want the source to be in a jet-dominated state: The X-rays will have to be in a jet-dominated state, and have an X-ray flux > 1e+10 erg/s. IR magnitude will have to be <15. We will get in touch with the XMM SOC 3 days before each observation, in order to trigger with enough response time. Similarly, we will communicate the source to the VLT, preparing the final Phase 2 material on time.