Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: X-Ray Observation of the L1157 Dark Cloud Region with ASCA   ASCA observation of a region containing a Class 0 protostar, IRAS 20386+6751
in the L1157 dark cloud, has been carried out. The protostar was not detected,
and the 95% upper limit to the luminosity depends on assumed Nh : Lx(0.5-10
keV) < 1.1e31 erg/s for Nh = 1e23 cm^-2. A Class I protostar in L1152, IRAS
20353+6742, in the same field was also undetected with the upper limit about
three times as much as the L1157 level. Besides these non detections, nine new
X-ray sources were detected and spectral analysis was performed for 4 sources.
One object (AXJ 2038+6801) shows a hard spectrum with a temperature kT = 8 keV
or a power-law photon index = 2.0 and absorbed with Nh = 2e22 cm^-2. Another
fainter one (AXJ 2036+6800) has a soft spectrum with most of the emission
falling below 2 keV. We examine possible nature of these new X-ray sources
based on their spectral properties.

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The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: nlin
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The categories of this paper are: nucl-th
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The categories of this paper are: eess
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The categories of this paper are: plasm-ph
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The categories of this paper are: math
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The categories of this paper are: hep-th
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The categories of this paper are: solv-int
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The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg