Abstract for Proposal 088008
Radio-quiet AGN in outburst
XMM-Newton observations of Seyfert galaxies established outbursts of
radio-quiet AGNs as a still poorly explored discovery space for AGN
physics with an enormous potential to learn: NGC 1566, HE1136-2304
and NGC 2617 are rare and extreme changing-look AGNs tracing rapid
changes in accretion and/or corona physics including the launching
of new outflows. GSN 069 very likely traces an AGN disturbed
by a tidal disruption event. We propose two 80ks simultaneous
XMM-Newton(EPIC&RGS)/NuSTAR observations accompanied by optical
spectroscopy of the next suited AGN outburst(s). They will allow tracing
the accretion physics, the launching of winds and outflows, the spectral
complexity connected with dramatic emission-line changes and possibly
the elusive tidal disruption events.
Details on Observing Strategy and Trigger Criteria
1. Either (a) an extreme increase in brightness by a factor of 15 in
X-rays, or two magnitudes in the optical (where AGN are known to vary
less); or (b) an event which shows a systematic rapid increase in one
waveband. \ 2. We will ask for a short Swift observation(s) to verify
that a candidate has an X-ray flux which is a factor of $>15$ higher
than the highest/quiescent flux found by previous X-ray missions. \
3. When an outburst is confirmed and only then, we will trigger a 80ks
simultaneous XMM-Newton&NuSTAR observation. The reaction time is about
one week. In addition, we will take a quasi-simultaneous observation
with a large optical telescope; SALT (in the South) or the Hobby-Eberly
Telescope (HET, in the North) are accessible to us. \ 4. In case the
Swift monitoring reveals an X-ray spectral change, we will trigger our
second XMM-Newton&NuSTAR observation.