相关论文: Heating of the IGM
Using a unified analytic model for quasars, galaxies, Lyman-alpha absorbers and the IGM, we obtain the redshift evolution of the temperature and the entropy of the gas and the corresponding cluster temperature - X-ray luminosity relation.…
XMM-Newton observations of the outskirts of the Coma cluster of galaxies confirm the existence of a soft X-ray excess claimed previously and show it comes from warm thermal emission. Our data provide a robust estimate of its temperature…
The role played by the intergalactic medium (IGM) in the X-ray absorption towards high-redshift sources has recently drawn more attention in spectral analysis studies. Here, we study the X-ray absorption towards 15 flat-spectrum radio…
Observations have established that the diffuse intergalactic medium (IGM) at z ~ 3 is enriched to ~0.1-1% solar metallicity and that the hot gas in large clusters of galaxies (ICM) is enriched to 1/3-1/2 solar metallicity at z=0. Metals in…
We present constraints on both the kinetic temperature of the intergalactic medium (IGM) at z=8.4, and on models for heating the IGM at high-redshift with X-ray emission from the first collapsed objects. These constraints are derived using…
We investigate evolution of the intracluster medium (ICM), considering the relaxation process between the ions and electrons. According to the standard scenario of structure formation, ICM is heated by the shock in the accretion flow to the…
A fraction of the thermal protons in the outer envelope of an X-ray cluster have velocities that exceed the local escape speed from the cluster gravitational potential. The Coulomb mean-free-path of these protons is larger than the virial…
Several popular cosmological models predict that most of the baryonic mass in the local universe is located in filamentary and sheet-like structures associated with groups and clusters of galaxies. This gas is expected to be gravitationally…
X-Ray observations of groups and clusters of galaxies show that the Intra-Cluster Medium (ICM) in their cores is hotter than expected from cosmological numerical simulations of cluster formation which include star formation, radiative…
We present two measurements of the temperature-density relationship (TDR) of the intergalactic medium (IGM) in the redshift range $2.55 < z < 2.95$ using a sample of 13 high-quality quasar spectra and high resolution numerical simulations…
Observational studies indicate that the intergalactic medium (IGM) is highly ionized up to redshifts just over 6. A number of models have been developed to describe the process of reionization and the effects of the ionizing photons from…
The strong deviation in the properties of X-ray clusters from simple scaling laws highlights the importance of non-gravitational heating and cooling processes in the evolution of proto-cluster gas. We investigate this from two directions:…
The circumgalactic medium (CGM) provides the material needed for galaxy formation and influences galaxy evolution. The hot ($T>10^6K$) CGM is poorly detected around galaxies with stellar masses ($M_*$) lower than $3\times10^{11}M_\odot$ due…
Using Suzaku data, we had found a $3.4\sigma$ evidence for the X-ray emitting warm-hot circumgalactic medium (CGM) in the L$^\star$ galaxy NGC 3221. Here we present XMM-Newton data and outline an efficient, rigorous and well-defined method…
We perform the first measurement of the thermal and ionization state of the intergalactic medium (IGM) across 0.9 < z < 1.5 using 301 \lya absorption lines fitted from 12 HST STIS quasar spectra, with a total pathlength of \Delta z=2.1. We…
The circumgalactic medium (CGM) is a multi-phase, dynamic interface between galaxy and the intergalactic medium, providing crucial diagnostics of galaxy evolution. However, direct evidence for a hot (million-Kelvin) CGM around present-day…
We revisit the phenomenon of elements diffusion in the intergalactic medium (IGM) in clusters of galaxies. The diffusion is driven by gravity, concentration and temperature gradients. The latter cause thermal diffusion, which has been so…
Turbulence driven by AGN activity, cluster mergers and galaxy motion constitutes an attractive energy source for heating the intracluster medium (ICM). How this energy dissipates into the ICM plasma remains unclear, given its low…
Feedback from massive stars is one of the least understood aspects of galaxy formation. We perform a suite of vertically stratified local interstellar medium (ISM) simulations in which supernova rates and vertical gas column densities are…
Recent years have brought more precise temperature measurements of the low-density intergalactic medium (IGM). These new measurements constrain the processes that heated the IGM, such as the reionization of H I and of He II. We present a…