Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The long-term evolution of the accreting millisecond X-ray pulsar Swift
  J1756.9-2508   We present a timing analysis of the 2009 outburst of the accreting
millisecond X-ray pulsar Swift J1756.9-2508, and a re-analysis of the 2007
outburst. The source shows a short recurrence time of only ~2 years between
outbursts. Thanks to the approximately 2 year long baseline of data, we can
constrain the magnetic field of the neutron star to be 0.4x10^8 G < B < 9x10^8
G, which is within the range of typical accreting millisecond pulsars. The 2009
timing analysis allows us to put constraints on the accretion torque: the spin
frequency derivative within the outburst has an upper limit of $|\dot{\nu}| <
3x10^-13 Hz/s at the 95% confidence level. A study of pulse profiles and their
evolution during the outburst is analyzed, suggesting a systematic change of
shape that depends on the outburst phase.

33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
18
The categories of this paper are: econ
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph