Objective
The aim of the project is to develop the next generation of the disc instability model (DIM) based on the code available at the Observatoire Astronomique de Strasbourg. This implicit code with an adaptive mesh developed by Jean-Marie Hameury is the best and most physical one presented so far. Interacting binaries represent undoubted the best opportunity to study the physics of accretion and it is now widely accepted that the outbursts in dwarf novae and soft X-ray transients are caused by thermal instabilities in the accretion disc around the compact object. Although the DIM explains a number of phenomena observed in these systems quite well, it fails with respect to others. The limitation of the success of the DIM obviously results from our ignorance of the nature of the viscosity. Conversely, we can derive constraints for the viscosity from appropriate observations of interacting binaries. During the two years in Strasbourg, I will confront the DIM with new observations of dwarf novae and soft X-ray transients and I will modify the model considering the recent advance in our understanding of MHD instabilities, which are generally thought to be the source of viscosity in accretion discs. This will provide important clues for our understanding of the nature of viscosity which probably constitutes the most fundamental physical process connected with accretion and has not yet been understood. It is worth noting that the expected results will considerable affect not only our picture of interacting binaries but also that of other astronomical objects like AGNs and YSOs.
Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
RGI - Research grants (individual fellowships)Coordinator
67000 STRASBOURG
France