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X-Ray Observation of the L1157 Dark Cloud Region with ASCA

T. Furusho·N. Y. Yamasaki·T. Ohashi·Y. Saito·W. Voges
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Abstract

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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T. Furusho, N. Y. Yamasaki, T. Ohashi, Y. Saito, W. Voges. 2000-06-09. X-Ray Observation of the L1157 Dark Cloud Region with ASCA. https://doi.org/10.1093/pasj%2F52.4.677

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