Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spinning-up: the case of the symbiotic X-ray binary 3A 1954+319   We present a timing and spectral analysis of the variable X-ray source 3A
1954+319. Our analysis is mainly based on an outburst serendipitously observed
during INTEGRAL Key Program observations of the Cygnus region in 2008 fall and
on the Swift/BAT longterm light curve. Previous observations, though sparse,
have identified the source to be one of only nine known symbiotic X-ray
binaries, i.e., systems composed of an accreting neutron star orbiting in a
highly inhomogeneous medium around an M-giant companion. The spectrum of 3A
1954+319 above 20 keV can be best described by a broken power law model. The
extremely long pulse period of ~5.3 hours is clearly visible in the
INTEGRAL/ISGRI light curve and confirmed through an epoch folding period
search. Furthermore, the light curve allows us to determine a very strong spin
up of -2x10^-4 h/h during the outburst. This spin up is confirmed by the pulse
period evolution calculated from Swift/BAT data. The Swift/BAT data also show a
long spin-down trend prior to the 2008 outburst, which is confirmed in archival
INTEGRAL/ISGRI data. We discuss possible accretion models and geometries
allowing for the transfer of such large amounts of angular momentum and
investigate the harder spectrum of this outburst compared to previously
published results.

36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
18
The categories of this paper are: econ
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an