Abstract for Proposal 094157
Catching the Rise and Fall of Tidal Disruption Events
XMM-Newton observations of X-ray TDEs have successfully detected slow
and ultrafast outflows, reflection signatures and other important
features. However, almost all deep observations were made around or
after the peak of the flares. In the next few years, with the launch
of Einstein Probe, hundreds of X-ray TDEs will be detected, with many
caught during the early rise phase. With special access to Einstein Probe
data, we propose to target a very bright X-ray TDE and carry out three
XMM-Newton observations during its rise, peak and decay phases. This
proposed program will be very useful for probing the rapidity of disk
formation, the production mechanisms of wind and corona, and the evolution
of the accretion flow properties in TDEs.
Details on Observing Strategy and Trigger Criteria
We request a total of three observations of a very bright TDE detected by
Einstein Probe. Two deeper looks of 80 ks each will be taken, one during
the rising phase and the other during the decay phase, when the X-ray
fluxes are at similar levels (F ~ e-11 erg cm^-2 s^-1). In addition,
one shorter look of 30 ks around peak luminosity will be taken. The first
observation will trigger when the X-ray flux reaches F>= e-11 erg cm^-2
s^-1 and still exhibits a relatively rapid rising pattern through the
tracking by Einstein Probe WXT and FXT. The triggering time of the second
and third observations will be, respectively, when the X-ray flux reaches
around maximum and when the flux drops back to F ~e-11 erg cm^-2 s^-1. A
fast reaction time (1-2 days) will be needed for the first observation to
catch the TDE in the rising phase. For the second and last observations,
a moderate reaction time around 5-10 days will be sufficient.