Related papers: Absorption studies of the most diffuse gas in the …
Approximately 30-40% of all baryons in the present day universe reside in a warm-hot intergalactic medium (WHIM), with temperatures between 10^5<T<10^7 K. This is a generic prediction from six hydrodynamic simulations of currently favored…
The Wisconsin H-Alpha Mapper (WHAM) is a new facility dedicated to the study of faint optical emission lines from diffuse interstellar gas. During its first 18 months of operation, WHAM carried out a survey of the interstellar H-alpha…
We review the current high-significance X-ray detections of Warm-Hot Intergalactic Medium (WHIM) filaments at z>0 along the lines of sight to the two blazars Mrk 421 (z=0.03) and 1ES 1028+511 (z=0.361). For these WHIM filaments, we derive…
Using a novel suite of cosmological simulations zooming in on a Mpc-scale intergalactic sheet or "pancake" at z~3-5, we conduct an in-depth study of the thermal properties and HI content of the warm-hot intergalactic medium (WHIM) at those…
We present an X-ray absorption line spectroscopic study of the large-scale hot interstellar medium (HISM) in the Galaxy. We detect Ne IX K$_\alpha$ absorption lines in the {\sl Chandra} grating spectra of seven Galactic low-mass X-ray…
The bulk of cosmic matter resides in a dilute reservoir that fills the space between galaxies, the intergalactic medium (IGM). The history of this reservoir is intimately tied to the cosmic histories of structure formation, star formation,…
Based on constraints from Big Bang nucleosynthesis and the cosmic microwave background, the baryon content of the high-redshift Universe can be precisely determined. However, at low redshift, about one-third of the baryons remain…
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 galaxy overdensities. This gas is expected to be gravitationally heated to…
The hot circum-galactic medium (CGM) represents the hot gas distributed beyond the stellar content of the galaxies while typically within their dark matter halos. It serves as a depository of energy and metal-enriched materials from…
A significant fraction of the local Universe's baryonic content remains undetected. Cosmological simulations indicate that most of the missing baryons reside in cosmic filaments in the form of warm-hot intergalactic medium (WHIM). The…
We present an analysis of the Lyman alpha forests of five quasar spectra in the near UV. Properties of the intergalactic medium (IGM) at an intermediate redshift interval (0.9 < z < 1.9) are studied. The amount of baryons in the diffuse…
The intrinsic X-ray emission of Gamma-Ray Bursts (GRBs) is often found to be absorbed over and above the column density through our own galaxy. The extra component is usually assumed to be due to absorbing gas lying within the host galaxy…
We report preliminary results on the detection of the Warm-Hot Intergalactic Medium (WHIM) along the line of sight toward the blazar 1ES 1028+511 (z = 0.361). 1ES 1028+511 was observed for 150 ks with the low energy transmission grating in…
The observational and theoretical status of the search for missing cosmological baryons is summarized, with a discussion of some indirect methods of detection. The thermal interpretation of the cluster soft X-ray and EUV excess phenomenon…
We perform a series of cosmological simulations using Enzo, an Eulerian adaptive-mesh refinement, N-body + hydrodynamical code, applied to study the warm/hot intergalactic medium. The WHIM may be an important component of the baryons…
We explore the multiphase structure of the circumgalactic medium (CGM) probed by synthetic spectra through a cosmological zoom-in galaxy formation simulation. We employ a Bayesian method for modelling a combination of absorption lines to…
This paper presents constraints on the cosmological density of baryons from a systematic search for O VII and O VIII absorption lines in the XMM-Newton and Chandra X-ray spectra of 51 background sources. The search is based on far…
Cold gas streaming along the dark-matter filaments of the cosmic web is predicted to be the major provider of resources for disc buildup, violent disk instability and star formation in massive galaxies in the early universe. We study to…
We make use of a 500ks Chandra HRC-S/LETG spectrum of the blazar H2356-309, combined with a lower S/N spectrum of the same target, to search for the presence of warm-hot absorbing gas associated with two Large-Scale Structures (LSSs)…
Cosmological hydrodynamic simulations predict that the low redshift universe comprises a web of warm-hot intergalactic gas and galaxies, with groups of galaxies and clusters forming at dense knots in these filaments. Our own Galaxy being no…