Grid of Lyα radiation transfer models for interpreting distant galaxies^⋆

¹ Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland
² Laboratoire d’Astrophysique de Toulouse-Tarbes, Université de Toulouse, CNRS, 14 Avenue E. Belin, 31400 Toulouse, France
³ Université de Lyon, Lyon, 69003 ; Université Lyon 1, Observatoire de Lyon, 9 avenue Charles André, 69230 Saint-Genis Laval ; CNRS, UMR 5574, Centre de Recherche Astrophysique de Lyon; École Normale Supérieure de Lyon, 69007 Lyon, France
⁴ Universität Zürich, Institute für Theoretische Physik, Winterthurerstrasse 190, 8057 Zürich, Switzerland
⁵ Laboratoire AIM, CEA/DSM - CNRS - Université Paris Diderot, IRFU/SAp, 91191 Gif-sur-Yvette, France

Received: 14 February 2011
Accepted: 26 April 2011

Abstract

Context. Lyα is a key diagnostic for numerous observations of distant star-forming galaxies, but detailed radiation transfer models are required for interpreting them.

Aims. We provide an extensive grid of 3D radiation transfer models that simulate the Lyα and UV continuum radiation transfer in the interstellar medium of star-forming galaxies.

Methods. We have improved our Monte Carlo McLya code and used it to compute a grid of 6240 radiation transfer models for homogeneous spherical shells containing Hi and dust surrounding a central source. The simulations cover a wide range of parameter space. We present the detailed predictions from our models including in particular the Lyα escape fraction f_esc, the continuum attenuation, and detailed Lyα line profiles.

Results. The Lyα escape fraction is shown to depend strongly on dust content, but also on other parameters (Hi column density and radial velocity). The predicted line profiles show a wide diversity of morphologies, ranging from broad absorption lines to emission lines with complex features. The results from our simulations are distributed in electronic format.

Conclusions. Our models should be of use for interpreting observations from distant galaxies, for other simulations, and should also serve as an important basis for comparison for future, more refined, radiation transfer models.