Oscar Agertz

Early onset of the hot circumgalactic medium around Milky Way galaxies

Abstract Hot coronae are key regulators in Milky Way (MW)-type galaxy formation and are thought to emerge once a galaxy’s dark matter halo crosses a critical mass threshold, Mvir ~ 1012 M⊙, so that accretion shocks can heat infalling gas to virial temperatures, Tvir. Here we inve...

MEGATRON: Reproducing the Diversity of High-Redshift Galaxy Spectra with Cosmological Radiation Hydrodynamics Simulations

We present the MEGATRON suite of cosmological radiation hydrodynamics simulations following the formation of Milky Way-mass galaxies from the earliest cosmic epochs when Population III stars form to Cosmic Noon. The suite represents the first set of cosmological simulations that...

MEGATRON: how the first stars can create an iron metallicity plateau in the smallest dwarf galaxies

We study the stellar mass-iron metallicity relation of dwarf galaxies in the new high-resolution MEGATRON cosmological radiation-hydrodynamics simulations. These simulations model galaxy formation up to z ≈ 8 in a region that will collapse into a Milky-Way-like galaxy at z = 0 ,...

MEGATRON: the impact of non-equilibrium effects and local radiation fields on the circumgalactic medium at cosmic noon

We present three cosmological radiation-hydrodynamic zoom simulations of the progenitor of a Milky Way-mass galaxy from the MEGATRON suite. The simulations combine on-the-fly radiative transfer with a detailed non-equilibrium thermochemical network (81 ions and molecules), resolv...

A steep mass transition for bar-driven interstellar medium structuring revealed by PHANGS-JWST

Galactic bars are thought to play a critical role in the secular evolution of their hosts by, for example, reorganising the interstellar medium (ISM). We used a sample of 57 star-forming disc galaxies observed with JWST at 3 and 7.7 µm to probe how the spatial distribution of pol...