Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The imprint of carbon combustion on a superburst from the accreting
  neutron star 4U 1636-536   Superbursts are hours-long X-ray flares attributed to the thermonuclear
runaway burning of carbon-rich material in the envelope of accreting neutron
stars. By studying the details of the X-ray light curve, properties of carbon
combustion can be determined. In particular, we show that the shape of the rise
of the light curve is set by the the slope of the temperature profile left
behind by the carbon flame. We analyse RXTE/PCA observations of 4U 1636-536 and
separate the direct neutron star emission from evolving photoionized reflection
and persistent spectral components. This procedure results in the highest
quality light curve ever produced for the superburst rise and peak, and
interesting behaviour is found in the tail. The rising light curve between 100
and 1000 seconds is inconsistent with the idea that the fuel burned locally and
instantaneously everywhere, as assumed in some previous models. By fitting
improved cooling models, we measure for the first time the radial temperature
profile of the superbursting layer. We find $d\ln T/d\ln P=1/4$. Furthermore,
20% of the fuel may be left unburned. This gives a new constraint on models of
carbon burning and propagation in superbursts.

29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess