Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optical Spectral Monitoring of XTE J1118+480 in Outburst: Evidence for a
  Precessing Accretion Disk?   We present spectroscopic observations of the X-ray transient XTE J1118+480
acquired during different epochs following the 2000 March outburst. We find
that the emission line profiles show variations in their double-peak structure
on time scales longer than the 4.1 hr orbital period. We suggest that these
changes are due to a tidally driven precessing disk. Doppler imaging of the
more intense Balmer lines and the HeII 4686 line shows evidence of a persistent
region of enhanced intensity superposed on the disk which is probably
associated with the gas stream, the hotspot or both. We discuss the possible
origins of the optical flux in the system and conclude that it may be due to a
viscously heated disk.

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The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
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The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol