Résumé / Abstract Journal-club_Exoplanetes

Séminaire Exoplanètes /
Seminar Exoplanets

« 3D LTE and NLTE spectral radiative transfer with IRIS. Application to accreting young stars. Opportunities for stellar and planetary atmospheres. »

Laurent Ibgui
Laboratoire d'Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères, Observatoire de Paris (Paris, France)

Steadily increasing computing capabilities allow the emergence of 3D radiation hydrodynamics (RHD) or magnetohydrodynamics (MHD) models of various astrophysical objects – e.g., accretion columns on Classical T Tauri Stars (CTTSs), protoplanetary disks, stellar and planetary atmospheres. It is therefore important to be able to test these models by comparing their predicted spectroscopic signatures with observations. I will present the generic 3D spectral radiative transfer code IRIS, which is specifically designed to directly post process 3D RHD or MHD simulations, in order to provide synthetic spectra emitted by the simulated structures. I will describe a few applications to radiative shocks, assuming local thermodynamic equilibrium (LTE). IRIS is being extended so that it can handle scattering and non-LTE effects. Possible future applications include calculations of spectral signatures of flows accreting on CTTSs and of stellar atmospheric structures. Finally, I will present a line-by-line code that I had developed for calculating infrared spectra of atmospheric paths, using HITRAN and HITEMP spectroscopic databases; this code may be coupled with IRIS, for applications to planetary atmospheres.
Tuesday 07 May 2024 - 14:00
Salle des séminaires Évry Schatzman
Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage