Kavli Affiliate: Debora Sijacki
| First 5 Authors: Yuxuan Yuan, Sergio Martin-Alvarez, Martin G. Haehnelt, Thibault Garel, Laura Keating
| Summary:
The visibility of the Lyman-$alpha$ (Ly$alpha$) emission from
reionization-epoch galaxies depends sensitively on the extent of the intrinsic
lya emission redwards of 1215.67~AA. The prominent red peak resulting from
resonant radiative transfer in the interstellar medium is often modelled as a
single Gaussian. We use the textsc{Azahar} simulation suite of a
massive-reionization epoch galaxy to show that a significantly larger fraction
of the lya emission extends to $400$-$800$~km~s$^{-1}$, and thus significantly
further to the red than predicted by a Gaussian line profile. A cycle of
frequent galaxy mergers strongly modulates the lya luminosity, the red peak
velocity and its extended red wing emerging from the galaxy, which all also
strongly vary with viewing angle. The lya emission also depends sensitively on
the implemented feedback, dust and star formation physics. Our simulations
including cosmic rays reproduce the observed spectral properties of
reionization epoch lya emitters (LAEs) well if we assume that the lya
emission is affected by very little dust. The visibility of LAEs can be
strongly underestimated if the extended red wings of the intrinsic lya
emission are not accounted for. We discuss implications for using the
visibility of LAEs to constrain the evolution of the volume-averaged neutral
fraction during reionization.
| Search Query: ArXiv Query: search_query=au:”Debora Sijacki”&id_list=&start=0&max_results=3