Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High energy emission from massive stars: the precocious X-Ray recovery
  of Eta Carinae after January 2009 minimum   We observed the massive binary stellar system of Eta Carinae in the 0.3-10
keV energy range with the X-ray Telescope onboard the Swift satellite during
the period 15 December 2008 - 11 March 2009, i.e. 1 month before to 2 months
after the X-ray drop from maximum to minimum, thought to be associated with the
periastron encounter of the primary star by the hot companion. Beginning a few
months before eclipse, the interaction between the winds of the two stars
intensifies and the X-ray flux reaches maximum. The flux drops dramatically
thereafter, subsiding in about 20 days to a level that is at least a factor 10
lower than the 'high state', i.e. the X-ray emission state of the system during
the largest fraction of its 5.52 yr orbit (~e-11 erg/s/cm2). Unlike in previous
cycles, when the low state lasted about 2.5 months, observations with RXTE
showed that the X-ray flux started its recovery to normal level about 1.5
months after the minimum. We suggest that this early recovery may be due to the
fact that the companion wind reaches terminal velocity before encountering the
shock.

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The categories of this paper are: hep-ex
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
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The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ph
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The categories of this paper are: stat
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The categories of this paper are: q-fin
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The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph