The Shape of the Relativistic Iron Kα Line from Mcg−6-30-15 Measured with the Chandra Hetgs and Rxte

We confirm the detection of the relativistically broadened iron Kα emission at 6.4 keV with simultaneous Chandra HETGS and RXTE PCA observations. Heavily binned HETGS data show a disk line profile with parameters very similar to those previously seen by ASCA. We observe a resolved narrow component with a velocity width ∼ 4700kms−1 (FWHM ∼ 11,000kms−1), that is most prominent, and narrower (FWHM ∼ 3600kms−1) when the continuum flux is high. It plausibly is just the blue wing of the broad line. We obtain a stringent limit on the equivalent width of an intrinsically narrow line in the source of 16 eV, indicating little or no contribution due to fluoresence from distant material such as the molecular torus. Variability studies of the narrow component show a constant iron line flux and variable width indicating the line may be originating from different kinematic regions of the disk. Subject headings: galaxies: active; quasars: general; X-ray: general; individual MCG−6-30-15