Work

Variable Partial Covering and a Relativistic Iron Line in Ngc 1365

Year: 2009

Type: article

Abstract: We present a complete analysis of the hard X-ray (2–10 keV) properties of the Seyfert galaxy NGC 1365, based on a 60 ks XMM-Newton observation performed in 2004 January. The two main results are as follows. (1) We detect an obscuring cloud with N H ∼ 3.5 × 10 23 cm −2 crossing the line of sight in ∼25 ks. This implies a dimension of the X-ray source not larger than a few 10 13 cm and a distance of the obscuring cloud of the order of 10 16 cm. Adopting the black hole mass M BH estimated from the M BH –velocity dispersion relation, the source size is D S < 20 R G and the distance and density of the obscuring clouds are R ∼ 3000–10, 000 R G and n ∼ 10 10 cm −3 , i.e., typical values for broad-line region clouds. (2) An iron emission line with a relativistic profile is detected with high statistical significance. A time-integrated fit of the line+continuum reflection components suggests a high iron abundance (approximately three times solar) and an origin of these components in the inner part (within ∼10 R G ) of the accretion disk, in agreement with the small source size inferred from the analysis of the absorption variability.

Source: The Astrophysical Journal

DOI: 10.1088/0004-637x/696/1/160