Max Gronke (University of Oslo, Norway)

Towards a theoretical understanding of Lyman-alpha observables
Wann Am 03.08.2017 von 14:30 bis 15:30
Was
  • Special Seminar
  • Kolloquium
Wo SH, Seminarraum
Termin übernehmen vCal / iCal

Lyman-alpha (Lya) is the most prominent emission line in the Universe, and it provides a unique window into the high redshift Universe. In this non-technical talk, I will discuss some examples of how Lya observables can be used to study, for instance, the Epoch of Reionization, and the composition of the interstellar and circumgalactic medium.

To do this I will present some efforts on the modelling of the Lya luminosity function, and what we might learn from this regarding the escape of ionizing photons. Furthermore, I will give a brief introduction to Lya radiative transfer. This will include some more recent results which suggest that the `clumpiness' is a critical parameter influencing radiative transfer, and that the Lya spectrum is in fact sensitive to features on far smaller scales than other observational techniques. These results might explain a number of puzzling observations, including evidence for tiny-scale structure in the gas and the fact that the spectra are best fit by homogeneous models, despite our knowledge that the ISM and CGM are multiphase.