Related papers: Preheating by Previrialization and its Impact on G…
In the hierarchical scenario of structure formation, galaxy clusters are the ultimate virialised products in mass and time. Hot baryons in the intracluster medium (ICM) and cold baryons in galaxies inhabit a dark matter dominated halo.…
Thermal regime of the baryons behind shock waves arising in the process of virialization of dark matter halos is governed at cetrain conditions by radiation of HD lines. A small fraction of the shocked gas can cool down to the temperature…
We present a model for the formation of the first galaxies before and after the reionization of hydrogen in the early universe. In this model, galaxy formation can only take place in dark matter haloes whose mass exceeds a…
Both preheating of the intergalactic medium and radiative cooling of low entropy gas have been proposed to explain the deviation from self-similarity in the cluster L_x-T_x relation and the observed entropy floor in these systems. However,…
Massive primordial halos exposed to moderate UV backgrounds are the potential birthplaces of supermassive black holes. In such a halo, an initially isothermal collapse will occur, leading to high accretion rates of…
Using X-ray constrained beta-models for the radial distribution of gas in the outskirts of galaxies, we analyze the termination of galactic winds and the formation and evolution of halo clouds by thermal instability. At low mass-loss rates,…
We study the impact of molecular (${\rm H_2}$) and atomic (HI) hydrogen cooling on the galaxy formation threshold. We calculate the fraction of dark matter (DM) halos that exceeds a critical mass required for star formation,…
The first stars, galaxies, star clusters, and direct-collapse black holes are expected to have formed in low-mass ($\sim$$10^{5}-10^{9} ~ M_{\odot}$) haloes at Cosmic Dawn ($z \sim 10 - 30$) under conditions of efficient gas cooling,…
The first generation of protogalaxies likely formed out of primordial gas via H2-cooling in cosmological minihalos with virial temperatures of a few 1000K. However, their abundance is likely to have been severely limited by feedback…
We investigate the origin of the variation of the gas mass fraction in the core of galaxy clusters, which was indicated by our work on the X-ray fundamental plane. The adopted model supposes that the gas distribution characterized by the…
We investigate thermal regime of the baryons behind shock waves arising in the process of virialization of dark matter halos. We find a fraction of the shocked gas cooled by radiation of HD molecules down to the temperature of the cosmic…
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…
Galactic halo gas traces inflowing star formation fuel and feedback from a galaxy's disk and is therefore crucial to our understanding of galaxy evolution. In this review, we summarize the multi-wavelength observational properties and…
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…
HD molecules can be an important cooling agent of the primordial gas behind the shock waves originated through mergings of the dark matter haloes at epochs when first luminous objects were to form. We study the necessary conditions for the…
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)…
We confirm that the standard assumption of isothermal, shock-heated gas in cluster potentials is unable to reproduce the observed X-ray luminosity- temperature relation of groups of galaxies. As an alternative, we construct a physically…
The galactic gaseous halo is a gas reservoir for the interstellar medium in the galaxy disk, supplying materials for star formation. We developed a gaseous halo model connecting the galaxy disk and the gaseous halo by assuming the star…
In a hierarchical picture of galaxy formation virialization continually transforms gravitational potential energy into kinetic energies of the baryonic and dark matter. For the gaseous component the kinetic, turbulent energy is transformed…
We develop a coupled model for the evolution of the global properties of the intergalactic medium (IGM) and the formation of galaxies, in the presence of a photoionizing background due to stars and quasars. We use this model to predict the…