EXOSAT observations of a quasar PKS 2135-147

Singh, K. P. ; Rao, A. R. ; Vahia, M. N. (1991) EXOSAT observations of a quasar PKS 2135-147 Astronomy & Astrophysics, 243 (1). pp. 67-70. ISSN 0004-6361

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Official URL: http://adsabs.harvard.edu/abs/1991A&A...243...67S


A study of X-ray emission from the low polarization quasar, PKS 2135-147 (PHL 1657), is presented based on the Exosat observations carried out on two occasions separated by a week in 1984. There is little evidence for any variations in the X-ray intensity on hourly time scales during either of the two observations. About 30 percent change in the soft X-ray (0.1-2 keV) intensity is, however, observed over a week. The observed X-ray spectral data is best fitted by a power law with a photon index Γ of 1.6±0.4 (error bars are with 90 percent confidence), and a line of sight column density consistent with the 21 cm observations. There is neither a detection of any significant low energy absorption within the quasar nor is there any evidence for soft X-ray excess.

Item Type:Article
Source:Copyright of this article belongs to EDP Sciences.
Keywords:Quasars: Individual- PKS 2135-147, PHL 1657; Galaxies; Nuclei of Radiation Mechanisms: General- X-rays: Spectroscopy
ID Code:59036
Deposited On:03 Sep 2011 12:08
Last Modified:18 May 2016 09:44

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