Spectra from accretion in young stars
Spectra and Data Analysis of Simulations of Accretions Shocks and Jets from Young Stars
Project leader: Laurent Ibgui (LERMA, Observatoire de Paris, Meudon)
Type of funding: Equipment (2013)
First results of radiative properties of accretion shocks around young stellar objects have been obtained with the current (which assumes local thermodynamic equilibrium) version of the 3D radiative transfer code IRIS. Based on a monodimensional gray radiation hydrodynamic model of the accretion shock provided by L. de Sá (Obs. Paris, Meudon) with the ASTROLABE code (developed by J.-P.Chièze, CEA), we built a 3D cylindrical structure of the accretion column. We found that the column is optically thin in longitudinal and transverse directions, except over an extremely narrow region in the vicinity of the shock front. We also highlighted the three-dimensional structure of the gray radiation flux (see figures below).
Figure 1. Gray radiation flux emitted by an accretion shock (simulations). Left: spatial distribution of the flux vector. Right: Spatial distribution of the flux magnitude (erg s-1 cm-2). (from Ibgui et al. ASP Conf. Series, ASTRONUM 2013 proceedings, submitted, 2014).
IRIS is currently being expanded to allow for non-LTE and scattering modeling. As this code will post-process large 3D MHD simulations and produce high-resolution spectra, it will face memory and CPU time constraints. To address this issue, IRIS is now being parallelized through hybrid schemes using MPI library and OpenMP interface. Then, IRIS will be able to make full use of the capabilities of the workstation funded by the Labex Plas@Par grant (ANR-11-IDEX-0004-02).