Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic fields, winds and X-rays of the massive stars in the Orion
  Nebula Cluster   In some massive stars, magnetic fields are thought to confine the outflowing
radiatively-driven wind. Although theoretical models and MHD simulations are
able to illustrate the dynamics of such a magnetized wind, the impact of this
wind-field interaction on the observable properties of a magnetic star - X-ray
emission, photometric and spectral variability - is still unclear. The aim of
this study is to examine the relationship between magnetism, stellar winds and
X-ray emission of OB stars, by providing empirical observations and confronting
theory. In conjunction with the COUP survey of the Orion Nebula Cluster, we
carried out spectropolarimatric ESPaDOnS observations to determine the magnetic
properties of massive OB stars of this cluster.

34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg