Conveners
Session 1: Session 1
- Andrei Mesinger
Simulations of the early structure formation and the Epoch of Reionization have
now reached sufficient volume, dynamic range and resolution to make reliable
predictions of the fundamental features and observable signatures of these
epochs at the full range of relevant scales. I will summarise important recent
progress our group has made in this area based on an ongoing,...
Cosmic Dawn III (CoDa III) is a fully-coupled radiation-hydrodynamics simulation of cosmic reionization and galaxy formation and their mutual impact, to redshift z < 5. CoDaIII was completed on Summit (Oak Ridge Leadership Computing Facility), and features an improved resolution in mass, 8 times higher compared to our previous iteration CoDa II. With 8192^3 particles and cells in a (94 Mpc)^3...
The latest ALMA and JWST observations provide new information on the formation
and evolution of galaxies in the early Universe, at the Epoch of Reionization. Of
particular importance are measurements of the molecular gas budget of these z >
5 objects, which is known to be the main fuel for star formation. A powerful
tool for measuring the gas content in galaxies at the Epoch of...
The 21cm signal from the Cosmic Dawn and the EoR contains extremely valuable information about many aspects of cosmology and astrophysics that cannot easily be obtained by other probes. I will start my talk by summarising our recent attempts to improve the modelling of the 21cm clustering signal, showing that we (and others) are still far away from the precision requirements of SKA-Low. In the...
In this work, we incorporate the stochastic nature of X-ray sources into the 21-cm signal simulations of Cosmic Dawn. Traditionally, simulations of the 21-cm line have assumed a constant or smoothly varying X-ray background. This simplicity, however, ignores the intrinsically stochastic distribution of X-ray sources, including X-ray binaries, which are believed to have a major impact on the...
The epoch of reionization marks the emergence of the first galaxies that emit light into the intergalactic medium, leading to the ionisation and heating of the Universe. This phase is at the forefront of astrophysics, serving as the era where the 'seeds' for modern-day galaxies were formed. While our current understanding relies on theoretical models of early galaxy formation within the...
The first stars, star clusters, and galaxies are expected to have formed in starbursts within low-mass halos at Cosmic Dawn. To test our understanding of Cosmic Dawn and ΛCDM, accurate predictions of their properties are crucial, especially as new high-redshift observations begin to emerge. Current cosmological simulations, are typically numerically expensive and lack either sub-parsec...
