X-ray reflection in the narrow-line Seyfert 1 galaxy 1H 0707-495

Abstract

We apply a reflection-dominated model to the second XMM-Newton observation of the narrow-line Seyfert 1 galaxy 1H 0707-495. As in the first XMM-Newton observation, a sharp spectral drop is detected with energy that has shifted from 7 to 7.5 keV in two years. The drop is interpreted in terms of relativistically blurred ionized reflection from the accretion disc, while the energy shift can be accounted for by changes in the ionization state and, more importantly, emissivity profile on the disc. A flatter emissivity profile during the second higher flux observation reduces gravitational redshift effects, therefore shifting the edge to higher energy. Remarkably, ionized disc reflection and the associated power-law continuum provide a reasonable description of the broad-band spectrum, including the soft excess. Considering both observations, the spectral variability in 1H 0707-495 appears to be a result of the interplay between these two spectral components. The reflection component in the second observation is significantly less variable than the power law. Changes of the emissivity profile, spectral shape and variability properties (such as the rms spectrum) within the two observations are all consistent with a recently proposed model in which relativistic effects in the very inner regions of the nucleus play a major role.