The question of whether early star-forming galaxies generated sufficient Lyman continuum (LyC) photons to drive cosmic reionisation is one of the major challenge in modern cosmology. Recent deep HST UV imaging and spectroscopy have revealed a signature of LyC leakage along the lines-of-sight of Lyman-alpha emitting galaxies. The observed correlations between LyC escape fraction, Lyman alpha...
The physical origin of low escape fractions of ionizing radiation derived from Lyman-break galaxies (LBGs) at $z\sim3$--$4$ is a puzzle in the theory of reionization. We perform idealized disk galaxy simulations to investigate how galactic properties, such as metallicity and gas mass, affect the escape of Lyman continuum (LyC) photons using radiation-hydrodynamic code, \texttt{RAMSES-RT}, with...
I will present scientific results from a Ramses-RT zoom-in simulation of a z=3 galaxy, run including the implementation of Monte Carlo tracer particles recently developed by Corentin Cadiou. I will show how tracer particles can be used to identify the Lagrangian origin of the gas emitting and scattering Lyman-alpha photons, and discuss how this informs the interpretation of recent observations...
To understand the role of galaxies during the epoch of reionization, it is essential to know more about the values of the escape fractions of ionizing photons from those galaxies. Since the intergalactic medium was opaque to lyman continuum radiation during reionization, it will never be possible to observe directly the escape fraction, so we have to rely on indirect measurements. One...
Neutral hydrogen in the IGM scatters light at 1216A producing an absorption spectrum that is observed on any background sources known as the Lyman-alpha forest. The fluctuations in the Lyman-alpha forest absorption can be used as a tracer of the varying density of intergalactic gas expected from the growth of structures from primordial fluctuations in the Universe. They can be accurately...
