Related papers: The First Galaxies: Signatures of the Initial Star…
Detection of the radiation emitted from some of the earliest galaxies will be made possible in the next decade, with the launch of the James Webb Space Telescope (JWST). A significant fraction of these galaxies may host Population (Pop) III…
We use large-scale cosmological simulations to study the prospect of observing Population III (Pop III) bright galaxies with the James Webb Space Telescope (JWST). To quantify the impact of radiative transfer (RT), we compare a simulation…
The He II \lambda 1640 emission line has been suggested as a direct probe of Population III (Pop III) stars at high-redshift, since it can arise from highly energetic ionizing photons associated with hot, metal free stars. We use the HST…
We perform high-resolution cosmological hydrodynamic simulations to study the formation of the first galaxies that reach the masses of $10^{8-9}~h^{-1}~M_\odot$ at $z=9$. The resolution of the simulations is high enough to resolve…
The first Pop III stars formed out of primordial, metal free gas, in minihalos at z>20, and kickstarted the cosmic processes of reionizaton and enrichment. While these stars are likely more massive than their enriched counterparts, the…
We examine the assembly process and the observability of a first galaxy (M_vir~10^9 solar mass at z~8) with cosmological zoom-in, hydrodynamic simulations, including the radiative, mechanical, and chemical feedback exerted by the first…
The James Webb Space Telescope (JWST) will enable observations of galaxies at redshifts z > 10 and hence allow to test our current understanding of structure formation at very early times. Previous work has shown that the very first…
The James Webb Space Telescope (JWST) has uncovered an abundance of $z>10$ galaxies bright in the ultraviolet (UV) that has challenged traditional theoretical models at high redshifts. Recently, various new models have emerged to address…
Recent findings from photometric and spectroscopic JWST surveys have identified examples of high-redshift galaxies at $z \gtrsim 10$. These high-$z$ galaxies appear to form much earlier and exhibit greater UV luminosity than predicted by…
We investigate the formation of a galaxy reaching a virial mass of $~ 10^8$ solar mass at $z=10$ by carrying out a zoomed radiation-hydrodynamical cosmological simulation. This simulation traces Population~III (Pop~III) star formation,…
Recent observations have gathered a considerable sample of high redshift galaxy candidates and determined the evolution of their luminosity function (LF). To interpret these findings, we use cosmological SPH simulations including, in…
The James Webb Space Telescope has discovered high luminosity galaxies that appear to be "too many" and "too massive" compared to predictions of the Standard LCDM cosmology, suggesting that star formation in the early universe is more rapid…
Detection of the first stars has remained elusive so-far but their presence may soon be unveiled by upcoming JWST observations. Previous studies have not investigated the entire possible range of halo masses and redshifts which may help in…
Our understanding of galaxy properties and evolution is contingent on knowing the initial mass function (IMF), and yet to date, the IMF is constrained only to local galaxies. Individual stars are now becoming routinely detected at…
Observations of both galaxies in the distant Universe and local starbursts are showing increasing evidence for very hard ionizing spectra that stellar population synthesis models struggle to reproduce. Here we explore the effects of the…
Population III (Pop. III) stars, as of yet, have not been detected, however as we move into the era of extremely large telescopes this is likely to change. One likely tracer for Pop. III stars is the HeII$\lambda1640$ emission line, which…
The properties of Population III (Pop III) stars impact many aspects of primeval structure formation such as the onset of cosmological reionization and early chemical enrichment. However, in spite of over twenty years of numerical…
The initial mass function (IMF) of the first (Population III) stars and Population II (Pop II) stars is poorly known due to a lack of observations of the period between recombination and reionization. In simulations of the formation of the…
The primary concern of this thesis is to understand the formation and properties of the first galaxies, as well as the influence of the first stars in terms of radiative, mechanical and chemical feedback. In particular, we elucidate the…
The recent launch of JWST has enabled the exciting prospect of detecting the first generation of metal-free, Population III (Pop. III) stars. Determining the emission line signatures that robustly signify the presence of Pop. III stars…