Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The 2016 super-Eddington outburst of SMC X-3: X-ray and optical
  properties and system parameters   On 2016 July 30 (MJD 57599), observations of the Small Magellanic Cloud by
Swift/XRT found an increase in X-ray counts coming from a position consistent
with the Be/X-ray binary pulsar SMC X-3. Follow-up observations on 2016 August
3 (MJD 57603) and 2016 August 10 (MJD 57610) revealed a rapidly increasing
count rate and confirmed the onset of a new X-ray outburst from the system.
Further monitoring by Swift began to uncover the enormity of the outburst,
which peaked at 1.2 x 10^39 erg/s on 2016 August 25 (MJD 57625). The system
then began a gradual decline in flux that was still continuing over 5 months
after the initial detection. We explore the X-ray and optical behaviour of SMC
X-3 between 2016 July 30 and 2016 December 18 during this super-Eddington
outburst. We apply a binary model to the spin-period evolution that takes into
account the complex accretion changes over the outburst, to solve for the
orbital parameters. Our results show SMC X-3 to be a system with a moderately
low eccentricity amongst the Be/X-ray binary systems and to have a dynamically
determined orbital period statistically consistent with the prominent period
measured in the OGLE optical light curve. Our optical and X-ray derived
ephemerides show that the peak in optical flux occurs roughly 6 days after
periastron. The measured increase in I-band flux from the counterpart during
the outburst is reflected in the measured equivalent width of the H-alpha line
emission, though the H-alpha emission itself seems variable on sub-day
time-scales, possibly due to the NS interacting with an inhomogeneous disc.

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The categories of this paper are: cond-mat
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
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The categories of this paper are: cs
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The categories of this paper are: q-alg
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The categories of this paper are: mtrl-th
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The categories of this paper are: math
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The categories of this paper are: physics
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int
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The categories of this paper are: comp-gas