Related papers: Voyage through the Hidden Physics of the Cosmic We…
According to modern cosmological models, galaxies are embedded within cosmic filaments, which supply a continuous flow of pristine gas, fueling star formation and driving their evolution. However, due to their low density, the direct…
Most of cosmic baryons predicted by the big-bang nucleosynthesis has evaded the direct detection. Recent numerical simulations indicate that approximately 30 to 50 percent of the total baryons in the present universe is supposed to take a…
I present an overview of some of the recent advances in our understanding of the distribution and evolution of the ordinary, baryonic matter in the universe. Two observations that strongly suggest that most of the baryons seen at high…
Continued star formation over the lifetime of a galaxy suggests that low metalicity gas is steadily flowing in from the circumgalactic medium. Also, cosmological simulations of large-scale structure formation imply that gas is accreted onto…
We report the detection of both soft and hard excess X-ray emission in the cluster of galaxies A 2199, based upon spatially resolved spectroscopy with data from the BeppoSAX, EUVE and ROSAT missions. The excess emission is visible at radii…
Observations of local X-ray absorbers, high-velocity clouds, and distant quasar absorption line systems suggest that a significant fraction of baryons may reside in multi-phase, low-density, extended, ~100 kpc, gaseous halos around normal…
The next generation X-ray observatory ASTRO-H will open up a new dimension in the study of galaxy clusters by achieving for the first time the spectral resolution required to measure velocities of the intracluster plasma, and extending at…
Models of galaxy formation in a CDM universe predict that massive galaxies are surrounded by a hot, quasi-hydrostatic circumgalactic corona of slowly cooling gas, predominantly accreted from the IGM. This prediction is borne out by the…
The circumgalactic medium (CGM) of the Milky Way is composed of a tenuous atmosphere filled with multi-phase plasma, including a warm-hot virialised component. Recent studies suggest a much hotter (~0.7 keV) super-virial component detected…
Within the standard framework of structure formation, where clusters and groups of galaxies are built up from the merging of smaller systems, the physical properties of the intracluster medium, such as the gas temperature and the total…
The angular power spectrum and polarization of the cosmic microwave background radiation (CMB), the relative abundances of primordial hydrogen, deuterium and helium isotopes, and the large-scale structure of the universe all indicate that…
The amount of detected baryons in the local Universe is at least a factor of two smaller than measured at high redshift. It is believed that a significant fraction of the baryons in the current Universe is "hiding" in a hot filamentary…
We construct simulated galaxy data sets based on the High Energy X-ray Probe (HEX-P) mission concept to demonstrate the significant advances in galaxy science that will be yielded by the HEX-P observatory. The combination of high spatial…
We used magneto-hydrodynamical cosmological simulations to investigate the cross-correlation between different observables (i.e. X-ray emission, Sunyaev-Zeldovich signal at 21 cm, HI temperature decrement, diffuse synchrotron emission and…
If the favored hierarchical cosmological model is correct, then the Milky Way system should have accreted and subsequently tidally destroyed ~100 low-mass galaxies in the past ~12 Gyr. We model this process using a hybrid semi-analytic plus…
Recently, the Pierre Auger Observatory has found strong evidence supporting the extragalactic origin of the most energetic cosmic rays. Despite several observed excesses in the distribution of arrival directions for the highest energy…
Clusters of galaxies are the most massive virialized structures in the Universe. The microphysical properties of the intracluster plasma can affect dynamical processes over an enormous range: from the feedback of active galactic nuclei to…
An unresolved X-ray glow (at energies above a few kiloelectronvolts) was discovered about 25 years ago and found to be coincident with the Galactic disk -the Galactic ridge X-ray emission. This emission has a spectrum characteristic of a…
Metals form an essential part of the Universe at all scales. Without metals we would not exist, and the Cosmos would look completely different. Metals are primarily born through nuclear processes in stars. They leave their cradles through…
Observations have argued that Milky Way (MW), Andromeda, and lower-mass galaxies exhibit extended soft X-ray diffuse halos to radii $R\gtrsim100\,$kpc in the circumgalactic medium (CGM). If interpreted as thermal emission, the shallow…