Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: X-ray Evidence for Supermassive Black Holes in Non-Active Galaxies.
  Subtitle: Detection of X-ray Flare Events, Interpreted as Tidal Disruptions
  of Stars by SMBHs   It has long been suggested that supermassive black holes in non-active
galaxies might be tracked down by occasional tidal disruptions of stars on
nearly radial orbits. A tidal disruption event would reveal itself by a
luminous flare of electromagnetic radiation. Theorists argued that the
convincing detection of such a tidal disruption event would be the observation
of an event which fulfills the following three criteria: (1) the event should
be of finite duration (a `flare'), (2) it should be very luminous (up to
L_{max} ~ 10^{45} erg/s in maximum), and (3) it should reside in a galaxy that
is otherwise perfectly {\em non-active} (to be sure to exclude an upward
fluctuation in gaseous accretion rate of an {\em active} galaxy). During the
last few years, several X-ray flare events were detected which match exactly
the above criteria. We therefore consider these events to be excellent
candidates for the occurrences of the theoretically predicted tidal disruption
flares.
  In this contribution, we review the previous observations of giant X-ray
flares from normal galaxies, present new results on these objects, critically
discuss alternatives to the favored outburst scenario, and report results from
our ongoing search for further tidal disruption flares based on the ROSAT
all-sky survey database.

11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg