Iron and nickel line properties in the X-ray-reflecting region of the Circinus galaxy

We discuss the iron and nickel properties in the nuclear X-ray-reflecting region of the Circinus galaxy, studied with XMM-Newton . The main results are as follows. (i) From the depth of the Fe Kalpha edge, a value of A(Fe)=1.7 in number with respect to the cosmic value (as for Anders & Grevesse) is measured, if the (not directly visible) illuminating spectrum is assumed to be that measured by BeppoSAX . If the slope of the primary power law is left free to vary, a steeper spectrum and a lower iron abundance (about 1.2) are found. (ii) From the Ni to Fe Kalpha line flux ratio, a nickel-to-iron abundance ratio of 0.055-0.075 is found. (iii) The Fe Kbeta/Kalpha flux ratio is slightly lower than expected, possibly due to a mild ionization of iron (which, however, cannot be much more ionized than x). (iv) The presence of the Fe Kalpha Compton shoulder, already discovered by Chandra , is confirmed, its relative flux implying Compton-thick matter. This further supports the identification of the reflecting region with the absorber.