Soft X-ray spectral analysis and black hole mass determination of Mrk 273

Abstract

A systematic analysis of the soft X-ray emission (0.1−2 keV ) from Mrk 273 was carried out by combining 5 observations taken between September 2016 and February 2017 with the ACIS-S camera from the Chandra data with the total observation time of 53.5 hours for the Southwest nucleus. We used a bulk-motion Comptonization bmc model for soft excess which is in general applicable to any physical system powered by accretion onto a compact object. We assume the existence of similar states of activity identified in supermassive and stellar mass black holes and used the scheme for black hole binaries of the accretion flow in different spectral states as a function of the total Eddington-scaled mass accretion rate ṁ . As a result, we obtained a value of SW nucleus black hole mass <inline1>, which is the first estimate of the mass of this nucleus in the literature.