  It has been demonstrated that active galactic nuclei are powered by gas
accretion onto supermassive black holes located at their centres. The paradigm
that the nuclei of inactive galaxies are also occupied by black holes was
predicted long ago by theory. In the last decade, this conjecture was confirmed
by the discovery of giant-amplitude, non-recurrent X-ray flares from such
inactive galaxies and explained in terms of outburst radiation from stars
tidally disrupted by a dormant supermassive black hole at the nuclei of those
galaxies. Due to the scarcity of detected tidal disruption events, the
confirmation and follow-up of each new candidate is needed to strengthen the
theory through observational data, as well as to shed new light on the
characteristics of this type of events. Two tidal disruption candidates have
been detected with XMM-Newton during slew observations. Optical and X-ray
follow-up, post-outburst observations were performed on these highly variable
objects in order to further study their classification and temporal evolution.
We show that the detected low-state X-ray emission for these two candidates has
properties such that it must still be related to the flare. The X-ray
luminosity of the objects decreases according to theoretical predictions for
tidal disruption events. At present, optical spectra of the sources do not
present any evident signature of the disruption event. In addition, the tidal
disruption rate as derived from the XMM-Newton slew survey has been computed
and agrees with previous studies.
