相关论文: Lyalpha heating and its impact on early structure …
The conditions for structure formation which ultimately lead to galaxies request further ingredients behind the simple collapse criteria. The Jean's criteria and the cooling criteria are those which are currently used. However in such a…
The first stars are thought to be one of the dominant sources of hydrogen reionization in the early Universe, with their high luminosities and surface temperatures expected to drive high ionizing photon production rates. In this work, we…
We present observational evidence of the correlation between the high-mass slope of the stellar initial mass function (IMF) in young star clusters and their stellar surface density, $\sigma_{*}$. When the high-mass end of the IMF is…
Observations of both galaxies in the distant Universe and local starbursts are showing increasing evidence for very hard ionizing spectra that stellar population synthesis models struggle to reproduce. Here we explore the effects of the…
We study the impact of thermal inflation on the formation of cosmological structures and present astrophysical observables which can be used to constrain and possibly probe the thermal inflation scenario. These are dark matter halo…
We investigate whether a single population of first stars could have influenced both the metal enrichment and reionization of the high-redshift intergalactic medium (IGM), by calculating the generated ionizing radiation per unit metal yield…
Magnetic fields and mass accretion processes create dark and bright spots on the surface of young stars. These spots manifest as surface thermal inhomogeneities, which alter the global temperature measured on the stars. To understand the…
We report on Smoothed Particle Hydrodynamics (SPH) simulations of the impact on a turbulent $\sim2\times10^{3}$ M$_{\odot}$ star--forming molecular cloud of irradiation by an external source of ionizing photons. We find that the ionizing…
Simulations predict that the first stars in an LCDM universe formed at redshifts z>20 in minihalos with masses of about 10^6 M_sun. We have studied their radiative feedback by simulating the propagation of ionization fronts (I-fronts)…
Studies of low redshift galaxy clusters suggest the intra-cluster medium (ICM) has experienced non-gravitational heating during the formation phase of the clusters. Using simple phenomenological heating prescriptions, we simulate the effect…
Observations of mergers of multi-compact object systems offer insights to the formation processes of massive stars in globular clusters. Simulations of stellar clusters, may be used to understand and interpret observations. Simulations…
The first stars in the Universe, the so-called Population III stars, form in small dark matter minihaloes with virial temperatures $T_{\rm vir} < 10^{4}$~K. Cooling in these minihaloes is dominated by molecular hydrogen (H$_{2}$), and so…
The leading contenders for the seeds of $z > 6$ quasars are direct-collapse black holes (DCBHs) forming in atomically-cooled halos at $z \sim$ 20. However, the Lyman-Werner (LW) UV background required to form DCBHs of 10$^5$ \Ms\ are…
Most structural and evolutionary properties of galaxies strongly rely on the stellar initial mass function (IMF), namely the distribution of the stellar mass formed in each episode of star formation. As the IMF shapes the stellar population…
The stellar initial mass function (IMF) describes the mass distribution of stars at the time of their formation and is of fundamental importance for many areas of astrophysics. The IMF is reasonably well constrained in the disk of the Milky…
The preheating of intergalactic medium(IGM) by structure collapsing and ultraviolet background(UVB) are investigated in cosmological hydrodynamical simulations. When gravitational collapsing is the sole heating mechanism, we find that (1)…
The Lyman-$\alpha$ photons couple the spin temperature of neutral hydrogen (HI) to the kinetic temperature during the era of cosmic dawn. During this process, they also exchange energy with the medium, heating and cooling the HI. In…
The critical star formation rate density required to keep the intergalactic hydrogen ionised depends crucially on the average rate of recombinations in the intergalactic medium (IGM). This rate is proportional to the clumping factor C =…
We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by $\Gamma_{\rm pe} = 1.2\times10^{-34}$ erg s$^{-1}$ cm$^{-3}$ $({\cal…
The theory for the formation of the first population of stars (Pop III) predicts an initial mass function (IMF) dominated by high-mass stars, in contrast to the present-day IMF, which tends to yield mostly stars with masses less than 1…