An observatory for mapping stellar accretion discs

Martin Still, Kieran O'brien, Keith Horne
A broad range of physical conditions occur within the atmosphere of any accretion disc. The characteristics of emergent disc spectra are strong functions of local disc physics, and consequently these spectra hold the key to determining physical disc structure. In general however astrophysical discs cannot be resolved spatially because of their small sizes and great distances, therefore our problem is that direct observations provide only a global picture of accretion disc physics. To test disc
more » ... sics. To test disc theory on local scales we require a method to deconvolve global spectra into their local constituents. We discuss one such method, Echo tomography, and the relevance of XMM to this eld of research.