Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: X-ray study of HLX1: intermediate-mass black hole or foreground neutron
  star?   We re-assess the XMM-Newton and Swift observations of HLX1, to examine the
evidence for its identification as an intermediate-mass black hole. We show
that the X-ray spectral and timing properties are equally consistent with an
intermediate-mass black hole in a high state, or with a foreground neutron star
with a luminosity of about a few times 10^{32} erg/s ~ 10^{-6} L_{Edd}, located
at a distance of about 1.5 to 3 kpc. Contrary to previously published results,
we find that the X-ray spectral change between the two XMM-Newton observations
of 2004 and 2008 (going from power-law dominated to thermal dominated) is not
associated with a change in the X-ray luminosity. The thermal component becomes
more dominant (and hotter) during the 2009 outburst seen by Swift, but in a way
that is consistent with either scenario.

15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex