Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The puzzling properties of the magnetic O star Tr16-22   (abridged version) Context : The detection of bright, hard, and variable
X-ray emission in Tr16-22 prompted spectropolarimetric observations of this
star, which in turn led to the discovery of a surface magnetic field. Aims : We
want to further constrain the properties of this star, in particular to verify
whether X-ray variations are correlated to changes in optical emission lines
and magnetic field strength, as expected from the oblique rotator model that is
widely accepted for magnetic O stars. Methods: We have obtained new
low-resolution spectropolarimetric and long-term high-resolution spectroscopic
monitoring of Tr16-22, and we also analyse new, serendipitous X-ray data.
Results: The new X-ray observations are consistent with previous data, but
their addition does not help to solve the ambiguity in the variation timescale
because of numerous aliases. No obvious periodicity or any large variations are
detected in the spectropolarimetric data of Tr16-22 obtained over three months.
The derived field values appear to be in line with previous measurements,
suggesting constancy of the field (though the possibility of small, short-term
field variations cannot be excluded). Variations in the equivalent widths of
Halpha are very small, and they do not appear to be related to the X-ray
timescale; the overall lack of large variations in optical emission lines is
consistent with the magnetic field constancy. In addition, variations of the
radial velocities indicate that Tr16-22 is probably a SB1 binary with a very
long period.

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The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
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The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph