Models for Dusty Lyα Emitters at High Redshift

Models are presented for the Lyman alpha emission of dusty high-redshiftgalaxies by combining the Press-Schechter formalism with a treatment of theinhomogeneous dust distribution inside galaxies. It is found that the amount ofLyman alpha radiation escaping from the galaxies strongly depends on the timeover which the dust is produced through stellar activity, and on the ambientinhomogeneity of the HII regions that surround the ionizing OB stars. Goodagreement is found with recent observations, as well as previousnon-detections. Our models indicate that the dust content builds up in no morethan approximately 5x10^8 yr, the galactic HII regions are inhomogeneous with acloud covering factor of order unity, and the overall star formation efficiencyis at least about 5%. It is predicted that future observations can detect theseLyman alpha galaxies upto redshifts of about 8.Comment: 16 pages, 4 figures, submitted to Ap