Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: IGR J17503-2636: a candidate supergiant fast X-ray transient   IGR J17503-2636 is a hard X-ray transient discovered by INTEGRAL on 2018
August 11. This was the first ever reported X-ray emission from this source.
Following the discovery, follow-up observations were carried out with Swift,
Chandra, NICER, and NuSTAR. We report in this paper the analysis and results
obtained from all these X-ray data. Based on the fast variability in the X-ray
domain, the spectral energy distribution in the 0.5-80 keV energy range, and
the reported association with a highly reddened OB supergiant at ~10 kpc, we
conclude that IGR J17503-2636 is most likely a relatively faint new member of
the supergiant fast X-ray transients. Spectral analysis of the NuSTAR data
revealed a broad feature in addition to the typical power-law with exponential
roll-over at high energy. This can be modeled either in emission or as a
cyclotron scattering feature in absorption. If confirmed by future
observations, this feature would indicate that IGR J17503-2636 hosts a strongly
magnetized neutron star with B~2e12 G.

37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs