Abstract for Proposal 092419
ToO observation of a blazar during a soft X-ray flare
We propose ToO observations of a blazar showing a soft X-ray flare
detected by the eROSITA telescope. Our knowledge of such events is very
limited due to the lack of sufficient soft X-ray monitoring, which has
only now become available through eROSITA. Together with multi-wavelength
monitoring, our proposed ToO observing strategy (10ks initially, 10ks
after 2weeks, and 20ks after 6months; plus 3ks contingency for background
flaring, respectively) will allow us to compare the SED during the soft
X-ray flare with that measured half a year later, when the source is
expected to be back in quiescence.
Details on Observing Strategy and Trigger Criteria
We want to trigger on the detection of a soft X-ray flare by one of
the blazars monitored by eROSITA. A flare is defined by an increase
of the soft X-ray flux by a factor of 10 or more, with respect to the
flux measured in the previous scan by eROSITA. We will only trigger on
confirmed, lesser studied blazars with an eROSITA flux of 1e-12 erg cm^-2
s^-1 (0.2-5 keV) or more during the flare. We request a 13ks observation
of the target, ideally within 24hours, but as soon as possible. A second
observation (13ks) should be conducted roughly 2 weeks after the first
one. A third pointing with 23ks exposure should be executed half a
year later.