Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Resolving different sources of fast X-ray variability of the dwarf nova
  RU Peg in quiescence   We analysed an X-ray light curve of the dwarf nova RU Peg taken by XMM-Newton
with a duration of 46300 s. The power density spectrum has a complicated shape
with two red noise and two white noise components, indicating the presence of
two turbulent regions. We developed a statistical "toy model" to study light
curves with variability produced by an unstable turbulent accretion flow from
the inner disc. Our results are consistent with a disc truncation radius
maximally 0.8 x 10^9 cm. We found that any fluctuation of the viscous mass
accretion at the inner disc are visible as UV and X-ray variations with the
same break frequency in the power density spectrum. This process is generating
low frequency variability. A second break suggests the presence of a faster
X-ray variability component which must be generated by another process likely
localised between the inner disc and the white dwarf.

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The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: funct-an
9
The categories of this paper are: nlin
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph