An accretion disc origin for the ‘X-ray broad-line region’ in 1H0707-495


E-mail: (AJB)


We use a 380-ks X-ray Multi-Mirror Mission–Newton (XMM–Newton) high-resolution Reflection Grating Spectrometer (RGS) spectrum to look for narrow spectral features from the nuclear environment of 1H0707-495. We do not find any evidence of a line-of-sight ionized wind (warm absorber). We do, however, detect broad emission lines, of width ∼5000 km s−1, consistent with O viii Lyα, N vii Lyα, C vi Lyα and an Fe xix/Fe xx/Ne ix Heα blend. Intriguingly, these lines have both blueshifted and redshifted components, whose velocity shifts are consistent with an origin in an accretion disc at ∼1600 Rg from the black hole. The features can be interpreted as the narrow-line cores of the disc reflection spectrum, thus providing independent support for the discline interpretation of the X-ray spectrum of 1H0707-495. We discuss the relevance of our findings for the ‘X-ray broad-line region’ in other Seyferts, and for the origins of the optical broad-line region itself.