JWST has provided an abundance of spectroscopic and photometric data during the Epoch of Reionisation and beyond. However, understanding the underlying physics of galaxies during these early epochs remains a formidable challenge as we rely on biased observational methodologies such as SED fitting to interpret the data and compare to simulations. I will present results from zoom-in...
With the James Web Telescope (JWST) offering a prime opportunity to observe Lyman-alpha (Lya) in the high-redshift Universe, understanding the information embedded in Lya observables and its relation to ionizing radiation has become a crucial task in the study of the Epoch of Reionization. Since Lya is sensitive to gas density, dust, and fragmentation, it provides vital information about the...
Constraining the Lyman continuum (LyC) escape fraction, fesc, at high redshifts is essential for mapping the ionizing emissivity of early galaxies during Reionization, but attenuation by the neutral IGM renders direct measurements impossible. As such, various diagnostics, such as [OIII]/[OII] ratios, UV-slope, etc., have been studied in local high-redshift analogs to develop techniques to...
Recent years have seen mounting evidence that the dominant contribution of
Lyman-Continuum photons driving cosmic Reionization has come from hot, massive stars in the first galaxies. How these photons have escaped the shroud of HI in their galaxies of origin to ionize the IGM is still debated and studied intensely. Many mechanisms have been suggested that can create the necessary escape...
Young star-forming galaxies are believed to be the main contributors to the process of cosmic reionization which completed roughly $1$ billion years after the big bang, at a redshift $z\sim6$. However, it is unclear whether such galaxies actually had sufficient ionizing escape fractions, as direct measurements are impossible due to the neutral intergalactic medium at this epoch. Indirect...
The reionisation of the IGM was driven by the first galaxies. However, the nature of these galaxies remains uncertain. This includes how many stars form in a galaxy, what types of stars form and what fraction of the ionising photons produced in the galaxy escape into the IGM. In particular, the ionising photon escape fraction is poorly constrained observationally and we lack a clear picture...
