Related papers: UV regulated star formation in high-redshift galax…
We investigate the ab-initio formation of super-massive stars in a pristine atomic cooling halo. The halo is extracted from a larger self-consistent parent simulation. The halo remains metal-free and star formation is suppressed due to a…
The character of the first galaxies at redshifts z > 10 strongly depends on their level of pre-enrichment, which is in turn determined by the rate of primordial star formation prior to their assembly. In order for the first galaxies to…
We examine aspects of primordial star formation in the presence of a molecular hydrogen-dissociating ultraviolet background. We compare a set of AMR hydrodynamic cosmological simulations using a single cosmological realization but with a…
Our goal is to study the effects of the UV radiation from the first stars, quasars and decays of the hypothetical Super Heavy Dark Matter (SHDM) particles on the formation of primordial bound objects in the Universe. We trace the evolution…
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…
The effects of the UV background radiation on the formation of sub-galactic clouds are studied by means of one-dimensional hydrodynamical simulations. The radiative transfer of the ionizing photons due to the absorption by HI, HeI and HeII,…
The first billion years in the evolution of the Universe mark the formation of the first stars, black holes and galaxies. The radiation from the first galaxies plays an important role in determining the final state of primordial gas…
We present a theoretical model embedding the essential physics of early galaxy formation (z = 5-12) based on the single premise that any galaxy can form stars with a maximal limiting efficiency that provides enough energy to expel all the…
Context. The seeds of the supermassive black holes (SMBHs) with masses of ~10^9 M_Sun observed already at z ~ 6 may have formed through the direct collapse of primordial gas in T_vir >~ 10^4 K halos, whereby the gas must stay hot (~10^4 K)…
Using radiation-hydrodynamic cosmological simulations, we present a detailed ($0.1$ pc resolution), physically motivated portrait of a typical-mass dwarf galaxy before the epoch of reionization, resolving the formation and evolution of star…
In massive primordial galaxies, the gas may directly collapse and form a single central massive object if cooling is suppressed. Line cooling by molecular hydrogen can be suppressed in the presence of a strong soft-ultraviolet radiation…
We explore possibilities of collapse and star formation in Population III objects exposed to the external ultraviolet background (UVB) radiation. Assuming spherical symmetry, we solve self-consistently radiative transfer of photons,…
The largest galaxies acquire their mass early on, when the Universe is still youthful. Cold streams violently feed these young galaxies a vast amount of fresh gas, resulting in very efficient star formation. Using a well resolved…
Population III stars are the first stars in the Universe to form at z=20-30 out of a pure hydrogen and helium gas in minihalos of 10^5-10^6 M$_\odot$ . Cooling and fragmentation is thus regulated via molecular hydrogen. At densities above…
Detailed high-resolution observations of the innermost regions of nearby galaxies have revealed the presence of supermassive black holes1. These black holes may interact with their host galaxies by means of 'feedback' in the form of energy…
We show that gaseous \HI disks of primordial composition irradiated by an external radiation field can develop a multiphase medium with temperatures between 10^2 and 10^4 K due to the formation of molecular hydrogen. For a given \HI column…
Photoionization by the high-redshift ultraviolet radiation background heats low density gas before it falls into dark matter potential wells, and it eliminates the neutral hydrogen and singly ionized helium that dominate cooling of…
Ionizing UV radiation and supernova flows amidst clustered minihalos at high redshift regulated the rise of the first stellar populations in the universe. Previous studies have addressed the effects of very massive primordial stars on the…
High redshift quasars at z>6 have masses up to ~$10^9$ M$_\odot$. One of the pathways to their formation includes direct collapse of gas, forming a supermassive star, precursor of the black hole seed. The conditions for direct collapse are…
An analysis of negative radiative feedback from resident stars in minihalos is performed. It is found that the most effective mechanism to suppress star formation is provided by infrared photons from resident stars via photo-detachment of…