Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Accretion in supergiant High Mass X-ray Binaries   Supergiant High Mass X-ray Binary systems (sgHMXBs) consist of a massive,
late type, star and a neutron star. The massive stars exhibits strong,
radiatively driven, stellar winds. Wind accretion onto compact object triggers
X-ray emission, which alters the stellar wind significantly. Hydrodynamic
simulation has been used to study the neutron star - stellar wind interaction
it two sgHMXBs: i) A heavily obscured sgHMXB (IGR J17252-3616) discovered by
INTEGRAL. To account for observable quantities (i.e., absorbing column density)
we have to assume a very slow wind terminal velocity of about 500 km/s and a
rather massive neutron star. If confirmed in other obscured systems, this could
provide a completely new stellar wind diagnostics. ii) A classical sgHMXB (Vela
X-1) has been studied in depth to understand the origin of the off-states
observed in this system. Among many models used to account for this observed
behavior (clumpy wind, gating mechanism) we propose that self-organized
criticality of the accretion stream is the likely reason for the observed
behavior. In conclusion, the neutron star, in these two examples, acts very
efficiently as a probe to study stellar winds.

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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: solv-int
1
The categories of this paper are: cs
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The categories of this paper are: mtrl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: eess
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The categories of this paper are: hep-lat