Observations of X-ray spectra of two nearby QSO's - MRK 205 and MRK 1148

Abstract

The 0.1-10 keY X-ray spectra of two nearby quasistellar objects (QSO's) known as Markarian 205 (Mrk 205) and Mrk 1148 (PG 0049 + 171), are presented based on observations with the EXOSAT Observatory. Simple power law models with the line of sight absorption consistent with the values obtained from the 21 em surveys are sufficient to explain the observed spectra of both the X-ray sources. The energy index (α) for the X­ ray spectrum of Mrk 205 is measured to be 0.96 ^+0.08_-0.08. The value of α for Mrk 1148 is found to be 0.61 ^+0.09_-0.10. These determinations assume that the column densities of equivalent hydrogen towards these sources are given by the accurate 21-cm measurements of Elvis et al. (1989). The present data do not require the presence of soft excess in these sources. There is no evidence for intrinsic absorption in these sources and no line features are detected in their X-ray spectra. The X-ray sources were found to be steady during the observations. The 2-10 keV X-ray luminosities of Mrk 205 and Mrk 1148 were 1.6 10⁴⁴ ergs ^-1 and 2.110⁴⁴ ergs^-1 respectively.