Physical parameter eclipse mapping

We present a new Eclipse Mapping method for reconstructing the properties of accretion discs in eclipsing catatclysmic variables. Physical Parameter Eclipse Mapping reconstructs spatially resolved maps of physical parameters such as temperatures and surface densities by fitting observed eclipse light curves at several wavelengths with the aid of a model describing the dependence of the disc spectrum on the physical parameters. Physical Parameter Eclipse Mapping has clear advantages over a classical approach for many applications. Most importantly, all of the available spectrophotometric data can be fitted simultaneously. The only drawback is the assumption of a physical model prior to the reconstructions. However, the method is very flexible in the choice of the spectral model, since the method itself does not depend on the choice. Furthermore, physical considerations, observations and experience will help determine the model to be used. The analysis with synthetic data shows that reliable parameter distributions can be obtained if the reconstruction behaviour of the model used is well understood. This means that the reconstructions are only as good as the model allows. In ambiguous parameter regions the method can (by definition) not give us the correct answer. However, in ambiguous-free zones, we show that the method indeed gives us the correct answer.