NAM2012 - All Presentation Details
Understanding X-ray Reflection in AGN
Author: Dan Wilkins
Institute of Astronomy, University of Cambridge
Co-Authors: A.C. Fabian (Institute of Astronomy, University of Cambridge)
Session: HE3: Multi-wavelength observations of compact objects
Presentation type: Talk 00:00 Poster Session B
High quality X-ray observations of AGN reveal a number of spectral features resulting from the reflection of X-ray continuum emission from a source in a corona surrounding the central black hole off the accretion disc. These features include the prominent iron K emission line at 6.4keV, broadened by relativistic effects close to the black hole and can probe right down to the event horizon. Detailed analysis of the emission line profile reveals the illumination pattern of the accretion flow by the X-ray source (the emissivity profile), which depends on a number of factors including the location and geometry of the primary X-ray source. Observed emissivity profiles are naturally explained by general relativistic effects on the rays and the accretion disc. Comparing observed emissivity profiles to systematic, high performance GPU-based ray tracing simulations relates the emissivity profile to the properties of the X-ray source. When combined with measurements of reverberation time lags, constraints can be placed on the location and geometry of the coronal X-ray sources in AGN from observed emissivity profiles. Such analysis has been completed for the narrow line Seyfert 1 galaxy 1H 0707-495 and other sources, revealing the location and extent of the primary X-ray source.