相关论文: Pre-heating of the intergalactic medium by gravita…

The cosmic ultraviolet background (UVB) heats the intergalactic medium (IGM), as a result the gas in dark matter halos below a certain mass is too hot to cool within a Hubble time. The UVB effectively suppresses the formation of dwarf…

A simple analytical model is used to calculate the X-ray heating of the IGM for a range of black hole masses. This process is efficient enough to decouple the spin temperature of the intergalactic medium from the cosmic microwave background…

The injection of turbulence in the circum-galactic medium at redshift z = 2 is investigated using the mesh-based hydrodynamic code Enzo and a subgrid-scale (SGS) model for unresolved turbulence. Radiative cooling and heating by a uniform…

Cosmological simulations show that, at the present time, a substantial fraction of the gas in the intergalactic medium (IGM) has been shock-heated to T>10^5 K. Here we develop an analytic model to describe the fraction of shocked,…

The physical characteristics of the Lyman-alpha forest cloud systems are combined with observations on the baryonic mass density of the Universe and constraints from primordial nucleosynthesis to set boundary conditions on the Intergalactic…

The intergalactic medium is expected to be at its coldest point before the formation of the first stars in the universe. Motivated by recent results from the EDGES experiment, we revisit the standard calculation of the kinetic temperature…

A definite prediction from recent N-body/hydro simulations of the structure formation of the universe is the presence of a diffuse intergalactic medium (IGM) in a temperature range of 10^5 - 10^7 K. This hot phase of the IGM may account for…

We estimate the heating of the intergalactic medium due to shocks arising from structure formation. Heating of the gas outside the collapsed regions, with small overdensities (${n_b \over {\bar n_b}}\ll 200$) is considered here, with the…

Structure in the Universe grew through gravitational instability from very smooth initial conditions. Energy conservation requires that the growing negative potential energy of these structures is balanced by an increase in kinetic energy.…

The ultraviolet background (UVB) emitted by quasars and galaxies governs the ionization and thermal state of the intergalactic medium (IGM), regulates the formation of high-redshift galaxies, and is thus a key quantity for modeling cosmic…

The time scale for cooling of the gravitationally bound gaseous intracluster medium (ICM) is not determined by radiative processes alone. If the ICM is in quasi-hydrostatic equilibrium in the fixed gravitational field of the dark matter…

We investigate the metallicity evolution and content of the intergalactic medium (IGM) and galactic halo gas from z=2->0 using 110-million particle cosmological hydrodynamic simulations. We focus on the detectability and physical properties…

We compare cosmological hydrodynamical simulations combined with the homogeneous metagalactic UV background (UVB) of Haardt & Madau (2012) (HM2012) to observations of the Lyman-alpha forest that are sensitive to the thermal and ionization…

Using the cosmic virial theorem, Press-Schechter analysis and numerical simulations, we compute the expected X-ray background (XRB) from the diffuse IGM with the clumping factor expected from gravitational shock heating. The predicted…

We study the temperature structure of the intergalactic medium (IGM) using a large cosmological N-body/SPH simulation. We employ a two-temperature model for the thermal evolution of the ionized gas, in which the relaxation process between…

We investigate the non-gravitational heating of hot gas in clusters of galaxies (intracluster medium; ICM) on the assumption that the gas is heated well before cluster formation ('preheating'). We examine the jet activities of radio…

The Universe is opaque to extragalactic very high-energy gamma rays (VHEGRs, E>100 GeV) because they annihilate and pair produce on the extragalactic background light. The resulting ultra-relativistic pairs are assumed to lose energy…

In this paper we review the current predictions of numerical simulations for the origin and observability of the warm hot intergalactic medium (WHIM), the diffuse gas that contains up to 50 per cent of the baryons at z~0. During structure…

We simulate the evolution of the intergalactic medium (IGM) in a universe dominated by a cosmological constant. We find that within a few Hubble times from the present epoch, the baryons will have two primary phases: one phase composed of…

Recent observations suggest that hydrogen reionization ends late ($z \simeq 6$) and proceeds quickly. We present here a new model of the meta-galactic UV/X-ray background (UVB) that is consistent with this. It adopts the most recent…