Related papers: X-ray halos in galaxies
The abundances of gas and dust (solids and complex molecules) in the interstellar medium (ISM) as well as their composition and structures impact practically all of astrophysics. Fundamental processes from star formation to stellar winds to…
There is increasing observational evidence that hot, highly ionized interstellar and intergalactic gas plays a significant role in the evolution of galaxies in the local universe. The primary spectral diagnostics of the warm-hot…
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…
The interstellar medium of galaxies, with temperatures reaching several million degrees, provides a pivotal perspective for understanding the physical and chemical properties of star formation, galactic evolution, and their associated…
Stellar halos may hold some of the best preserved fossils of the formation history of galaxies. They are a natural product of the merging processes that probably take place during the assembly of a galaxy, and hence may well be the most…
In this chapter, we give an overview of the major components of the interstellar medium (ISM) in galaxies at a level appropriate for upper level undergraduates or beginning graduate students. We discuss the major constituents of the the ISM…
Elliptical galaxies are generally luminous sources of X-ray radiation, and contain large amounts of hot, interstellar gas. In the brighter X-ray galaxies, the inferred masses of hot gas are consistent with those expected given the present…
Clusters of galaxies are studied from a theoretical point of view, comparing with observational results whenever possible. The problem is approached both analytically as well as by means of high-resoultion numerical simulations. The dark…
As the formation of cosmic structure continues to proceed, we observe one of the latest stages of this process in mergers of clusters of galaxies with other clusters, groups, and galaxies. The X-ray emitting hot plasma of these systems can…
X-ray spectra of galaxy clusters are dominated by the thermal emission from the hot intracluster medium. In some cases, besides the thermal component, spectral models require additional components associated, e.g., with resonant scattering…
Multiphase gas -- ranging from cold molecular clouds ($\lesssim 100\,$K) to hot, diffuse plasma ($\gtrsim 10^6\,$K) is a defining feature of the interstellar, circumgalactic, intracluster, and intergalactic media. Accurately simulating its…
The Universe has evolved from an initial diffuse, uniform gas to a complex structure that includes both voids and high-density galaxy clusters connected by gaseous filaments, known as the Cosmic Web, and traced by 3D surveys of galaxies.…
The physical processes by which gas is accreted onto galaxies, transformed into stars and then expelled from galaxies are of paramount importance to galaxy evolution studies. Observationally constraining each of these baryonic components in…
A large fraction of the baryons and most of the metals in the Universe are unaccounted for. They likely lie in extended galaxy halos, galaxy groups, and the cosmic web, and measuring their nature is essential to understanding galaxy…
In this contribution we present a few selected examples of how the latest generation of space-based instrumentation -- NASA's Chandra X-ray Observatory and the Far-Ultraviolet Spectroscopic Explorer (FUSE) -- are finally answering old…
Galaxies evolve under the influence of gas flows between their interstellar medium and their surrounding gaseous halos known as the circumgalactic medium (CGM). The CGM is a major reservoir of galactic baryons and metals, and plays a key…
Optically-similar early-type galaxies are observed to have a large and poorly understood range in the amount of hot, X-ray-emitting gas they contain.To investigate the origin of this diversity, we studied the hot gas properties of all 42…
Recent observations show that spiral galaxies are surrounded by extended gaseous halos as predicted by the hierarchical structure formation scenario. The origin and nature of extraplanar gas is often unclear since the halo is continuously…
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)…
A decade of X-ray stellar observations with Chandra and XMM-Newton has led to significant advances in our understanding of the physical processes at work in hot (magnetized) plasmas in stars and their immediate environment, providing new…