Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thomson Thick X-ray Absorption in a Broad Absorption Line Quasar
  PG0946+301   We present a deep ASCA observation of a Broad
  Absorption Line Quasar (BALQSO) PG0946+301. The source was clearly detected
in one of the gas imaging spectrometers, but not in any other detector. If
BALQSOs have intrinsic X-ray spectra similar to normal radio-quiet quasars, our
observations imply that there is Thomson thick X-ray absorption (N_H >~10^{24}
cm^{-2}) toward
  PG0946+301. This is the largest column density estimated so far toward a
BALQSO. The absorber must be at least partially ionized and may be responsible
for attenuation in the optical and UV. If the
  Thomson optical depth toward BALQSOs is close to one, as inferred here, then
spectroscopy in hard X-rays with large telescopes like XMM would be feasible.

33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org