Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: RXTE Observations of LMC X-1   The luminous X-ray binary and black-hole candidate LMC X-1 has been observed
with the Rossi X-ray Timing Explorer (RXTE) to search for quasi-periodic
oscillations (QPO), previously reported in its high state. The source was
observed monthly in a series of nine observations. Analysis of the temporal
variations shows no evidence for QPO or other periodic changes, but
correlations between the high-energy light curve and hardness of the spectrum
are described. Spectral fits with two-component models demonstrate that the
hardness variations come from changes in the intensity of the high-energy
power-law tail.

36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex