Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The discovery of quiescent X-ray emission from SAX J1808.4-3658, the
  transient 2.5ms pulsar   We report on a 20 ks BeppoSAX observation of the transient 2.5 ms X-ray
pulsar SAX J1808.4-3658 in its quiescent state. A source at a level of ~ 3 x
10^-3 c/s was detected with the BeppoSAX/MECS at a position consistent with
that of SAX J1808.4-3658. The inferred 0.5-10 keV luminosity was to that
measured from other quiescent low mass X-ray transients hosting an old neutron
star. This result is discussed in the light of the propeller and radio pulsar
shock emission models for the quiescent emission of these systems.

26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th