Speaker
Jens Melinder
Description
The Lyman apha reference sample (LARS) is a major multiwavelength imaging and
spectroscopic campaign of local normal star-forming galaxies, UV-luminous starburst
systems, and luminous infrared galaxies using HST and ground-based telescopes. The
aim of this survey is to probe what physical conditions and processes regulate the
emission of Lyα radiation on local and global galactic scales. The Ly alpha line is
widely used to identify and confirm galaxies in the distant universe, close to the
epoch when the first galaxies formed and when the universe was reionized. However,
the fact that Ly alpha is a resonant line makes it optically thick even at relatively
low neutral hydrogen column densities. This means that the radiative transport of Ly
alpha photons through galaxies is a complex problem where the structure, kinematics
and dust content, and neutral hydrogen content of the interstellar medium all
contribute to the process. In this talk I will present the current status of the
project including: unique HST Ly alpha maps and FUV spectroscopy of 44 galaxies
within the LARS sample, HI observations with GBA and VLA for a subset of the sample,
IFU spectroscopy using CAHA/PMAS and VLT/MUSE for a subset of the sample. The first
published results of the LARS survey reveal that when Ly alpha manages to escape it
does so in the form of diffuse scattering halos.
