Related papers: Low-temperature primordial gas in merging halos
We investigate the baryon content of the circumgalactic medium (CGM) within the virial radius of $M_h \sim 10^{12} \; M_\odot$ haloes at z ~ 3, by modelling the surface brightness profile of the giant Ly$\alpha$ nebulae recently discovered…
Understanding star formation is problematic as it originates in the large scale dynamics of a galaxy but occurs on the small scale of an individual star forming event. This paper presents the first numerical simulations to resolve the star…
The detection of $\rm z>6$ quasars reveals the existence of supermassive black holes of a few $\rm 10^9~M_{\odot}$. One of the potential pathways to explain their formation in the infant universe is the so-called direct collapse model which…
Context. To understand the formation of the first stars, a detailed description of the thermal and chemical processes in collapsing gas clouds is essential. Molecular cooling, particularly via H2, plays a significant role in triggering…
The present structure of galaxies is governed by the radiative dissipation of the gravitational and supernova energy injected during formation. A crucial aspect of this process is whether the gas cools as fast as it falls into the…
I present an overview of some of the recent advances in our understanding of the distribution and evolution of the ordinary, baryonic matter in the universe. Two observations that strongly suggest that most of the baryons seen at high…
We examine the temperature history of gas accreted by forming galaxies in SPH simulations. About half the gas shock heats to roughly the virial temperature of the galaxy potential well before cooling, condensing, and forming stars, but the…
High-redshift luminous quasars powered by accreting supermassive black holes (SMBHs) with mass $\gtrsim 10^9 M_\odot$ constrain their formation pathways. We investigate the formation of heavy seeds of SMBHs through gas collapse in the…
The first generation of stars produces a background of Lyman-Werner (LW) radiation which can photo-dissociate molecular hydrogen, increasing the mass of dark matter halos required to host star formation. Previous studies have determined the…
Gas rich sub-galactic halos with mass Mt <= 10^7.5 Msun, while incapable of forming stars due to lack of adequate coolants, contain a large fraction of baryonic mass at cosmological reionization. We show that the reionization of the…
Supermassive stars (SMSs) and heavy seed black holes, as their remnants, are promising candidates for Supermassive Black Hole (SMBH) progenitors, especially for ones observed in the early universe $ z\simeq 8.5-10$ by recent JWST…
The origin of supermassive black holes is an open question that has been explored considering gas- and collision-based formation channels to explain the high number of quasars observed in the early Universe. According to numerical…
We utilize cosmological hydrodynamic simulations to study the formation of Population III (Pop III) stars in dark matter halos exposed to strong ionizing radiation. We simulate the formation of three halos subjected to a wide range of…
Recently the initial supersonic relative velocity between the dark matter and baryons was shown to have an important effect on galaxy formation at high redshift. We study the impact of this relative motion on the distribution of the…
The condensation of baryons within a dark matter (DM) halo during galaxy formation should result in some contraction of the halo as the combined system settles into equilibrium. We quantify this effect on the cuspy primordial halos…
The free streaming of warm dark matter particles dampens the fluctuation spectrum, flattens the mass function of haloes and imprints a fine grained phase density limit for dark matter structures. The phase space density limit is expected to…
First stars play crucial roles in development of the universe, influencing events like cosmic reionization and the chemical enrichment. While first stars are conventionally thought to form at around $z \sim 20-30$ in the standard $\Lambda$…
In the prevailing model of galaxy formation and evolution, the process of gas accretion onto central galaxies undergoes a transition from cold-dominated to hot-dominated modes. This shift occurs when the mass of the parent dark matter halos…
We outline a scenario of galaxy formation in which the gas in galaxy-forming regions was preheated to high entropy by vigorous energy feedback associated with the formation of stars in old ellipticals and bulges and with AGN activity. Such…
If primordial black holes (PBHs) formed at the quark-hadron epoch, their mass must be close to the Chandrasekhar limit, this also being the characteristic mass of stars. If they provide the dark matter (DM), the collapse fraction must be of…