Related papers: Detecting the warm-hot intergalactic medium throug…
Numerical simulations of the intergalactic medium have shown that at the present epoch a significant fraction (40-50%) of the baryonic component should be found in the (T~10^6K) Warm-Hot Intergalactic Medium (WHIM) - with several recent…
We present the first >=3.5 sigma (conservative) or >=5.8 sigma (sum of lines significance) detection of two Warm-Hot Intergalactic Medium (WHIM) filaments at z>0, which we find along the line of sight to the blazar Mkn 421. These systems…
In a previous paper we reported a 3-sigma detection of an absorption line from the Warm-Hot Intergalactic Medium (WHIM) using the Chandra and XMM X-ray grating spectra of the blazar H2356-309, the sight-line of which intercepts the Sculptor…
We discuss physical properties and the baryonic content of the Warm-hot Intergalactic Medium (WHIM) at low redshifts. Cosmological simulations predict that the WHIM contains a large fraction of the baryons at z=0 in the form of…
This paper presents initial results of a systematic search for resonance X-ray absorption lines from H-like O VIII and He-like O VII caused by the intervening warm-hot intergalactic medium (WHIM). The search is based on far ultra-violet…
We report a ~3 sigma detection of a 21.82 A absorption feature in the direction of the BL Lac MRK 421 which is interpreted as OVII K(alpha) at z~0.01. This corresponds to the redshift of a H absorber in a cosmic void detected by HST along…
Modern analyses of structure formation predict a universe tangled in a 'cosmic web' of dark matter and diffuse baryons. These theories further predict that at low-z, a significant fraction of the baryons will be shock-heated to $T \sim…
Hydrodynamical simulations indicate that substantial fraction of baryons in the Universe remains in a diffuse component - Warm-Hot Intergalactic Medium (WHIM). To determine physical properties (spatial distribution, temperature and density)…
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…
The number of detected baryons in the Universe at z<0.5 is much smaller than predicted by standard big bang nucleosynthesis and by the detailed observation of the Lyman alpha forest at red-shift z=2. Hydrodynamical simulations indicate that…
We assess the possibility to detect the warm-hot intergalactic medium (WHIM) in emission and to characterize its physical conditions and spatial distribution through spatially resolved X-ray spectroscopy, in the framework of the recently…
Most of the baryonic mass in the circumgalactic medium (CGM) of a spiral galaxy is believed to be warm-hot, with temperature around $10^6$K. The narrow OVI absorption lines probe a somewhat cooler component at $\log \rm T(K)= 5.5$, but…
It has been known for decades that the observed number of baryons in the local universe falls about 30-40% short of the total number of baryons predicted by Big-Bang Nucleosynthesis, as inferred from density fluctuations of the Cosmic…
We discuss the detectability of Warm/Hot Intergalactic medium (WHIM) via the absorption lines toward bright point sources with a future X-ray satellite mission, XEUS. While we consider bright QSOs as specific examples, the methodology can…
The circumgalactic medium (CGM) around galaxies is believed to record various forms of galaxy feedback and contain a significant portion of the "missing baryons" of individual dark matter halos. However, clear observational evidence for the…
The "missing baryons", in the form of warm-hot intergalactic medium (WHIM), are expected to reside in cosmic filamentary structures that can be traced by signposts such as large-scale galaxy superstructures. The clear detection of an X-ray…
The amount of baryons hosted in the disks of galaxies is lower than expected based on the mass of their dark-matter halos and the fraction of baryon-to-total matter in the universe, giving rise to the so called galaxy missing-baryon…
The current census of observed baryons in the local Universe is still missing a significant fraction of them according to standard Big-Bang nucleosynthesis. Numerical simulations predict that most of the missing baryons are in a hot…
The relationship between galaxies and the state/chemical enrichment of the warm-hot intergalactic medium (WHIM) expected to dominate the baryon budget at low-z provides sensitive constraints on structure formation and galaxy evolution…
We present the high-resolution X-ray spectra of Mkn 421 obtained in November 2003 with the RGS aboard the XMM-Newton satellite. This Target of Opportunity observation was triggered because the source was in a high state of activity in the…