Related papers: Hybrid Cosmological Simulations with Stream Veloci…
We study the gas content of halos in the early universe using high resolution hydrodynamical simulations. We extract from the simulations and also predict based on linear theory the halo mass for which the enclosed baryon fraction equals…
We study the properties of gas in and around 10^12 solar mass halos at z=2 using a suite of high-resolution cosmological hydrodynamic 'zoom' simulations. We quantify the thermal and dynamical structure of these gaseous reservoirs in terms…
We investigate the coupled formation and evolution of galaxies and their embedded supermassive black holes using state-of-the-art hydrodynamic simulations of cosmological structure formation. For the first time, we self-consistently follow…
We discuss an implementation of a deep learning framework to gain insight into dark matter (DM) structure formation. We investigate the contribution of velocity and density field information to the construction of the halo mass function…
We introduce the Ultramarine simulation, an extremely large $N$-body simulation of the structure formation and evolution to redshift 5.5 at which cosmic reionization was just completed. The simulation evolves 2.1 trillion particles within a…
Simulations of cosmological filamentary accretion reveal flows ("streams") of warm gas, ~$10^4$ K, which are efficient in bringing gas into galaxies. We present a phenomenological scenario where gas in such flows -- if it is shocked as it…
We investigate the suppression of the baryon density fluctuations compared to the dark matter in the linear regime. Previous calculations predict that the suppression occurs up to a characteristic mass scale of ~ 1,000,000 solar masses,…
Baryonic streaming motions produced prior to the epoch of recombination became supersonic during the cosmic dark ages. Various studies suggest that such streaming velocities change the halo statistics and also influence the formation of…
Dark matter sub-halos that pass near or through a thin tidal star stream locally increase its velocity dispersion. Subsequent orbital evolution further increases the velocity dispersion and stream width, lowering the surface density of a…
We study the velocities of the accretion along streams from the cosmic web into massive galaxies at high redshift with the help of three different suites of AMR hydrodynamical cosmological simulations. The results are compared to free-fall…
We present an overview of some of the issues surrounding current models of galaxy formation, highlighting recent insights obtained from cosmological hydrodynamic simulations. Detailed examination of gas accretion processes show a hot mode…
We present a systematic study of the cosmic variance that existed in the formation of first stars and galaxies. We focus on the cosmic variance induced by the large-scale density and velocity environment engraved at the epoch of…
The first dark matter halos form by direct collapse from peaks in the matter density field, and evidence from numerical simulations and other analyses suggests that the dense inner regions of these objects largely persist today. These halos…
We introduce a new set of eight Milky Way-sized cosmological simulations performed using the AMR code ART + Hydrodynamics in a LCDM cosmology. The set of zoom-in simulations covers present-day virial masses in the 0.83-1.56 x 10^12 msun…
Measurements of velocity and density perturbations along stellar streams in the Milky Way provide a time integrated measure of dark matter substructure at larger galactic radius than the complementary instantaneous inner halo strong lensing…
We study dwarf galaxy formation at high redshift ($z\ge5$) using a suite of high- resolution, cosmological hydrodynamic simulations and a semi-analytic model (SAM). We focus on gas accretion, cooling and star formation in this work by…
Primordial dark matter (DM) haloes are the smallest gravitationally bound DM structures from which the first stars, black holes, and galaxies form and grow in the early universe. However, their structures are sensitive to the free streaming…
We use the photon flux and absorption tracer algorithm presented in Katz et al.~2018, to characterise the contribution of haloes of different mass and stars of different age and metallicity to the reionization of the Universe. We employ a…
We use hydrodynamic simulations to examine how the baryonic components of galaxies are assembled, focusing on the relative importance of mergers and smooth accretion in the formation of ~L_* systems. In our primary simulation, which models…
We introduce the ASTRID simulation, a large-scale cosmological hydrodynamic simulation in a $250$ Mpc/h box with $2\times 5500^3$ particles. ASTRID contains a large number of high redshift galaxies, which can be compared to future survey…