Related papers: Probing the Intergalactic Medium with the OVI Fore…
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…
The hot interstellar medium traces the stellar feedback and its role in regulating the eco-system of the Galaxy. I review recent progress in understanding the medium, based largely on X-ray absorption line spectroscopy, complemented by…
(Abridged) We present fine structure and recombination lines observations of the ionized gas toward a sample of 18 sources located within 300 pc of the center of the Galaxy (GC). The fine structure lines from [NII] and [SIII] have been…
The optical filaments found in many cooling flows in galaxy clusters consist of low density ($\sim 10^3 \pcc$) cool ($\sim 10^3$ K) gas surrounded by significant amounts of cosmic-ray and magnetic-field energy. Their spectra show…
(Abridged) We study metal absorption around 854 $z\approx$2.4 star-forming galaxies taken from the Keck Baryonic Structure Survey (KBSS). The galaxies examined in this work lie in the fields of 15 hyper-luminous background QSOs, with galaxy…
Observations of quasar absorption line systems reveal that the z=3 intergalactic medium (IGM) is polluted by heavy elements down to HI optical depths tau_HI<<10. What is not yet clear, however, is what fraction of the volume needs to be…
We study HI and metal-line absorption around $z\approx2$ star-forming galaxies by comparing an analysis of data from the Keck Baryonic Structure Survey to mock spectra generated from the EAGLE cosmological, hydrodynamical simulations. We…
Early-type galaxies often contain a hot X-ray emitting interstellar medium (3-8E6 K) with an apparent radiative cooling time much less than a Hubble time. If unopposed by a heating mechanism, the gas will radiatively cool to temperatures <=…
We present results of gasdynamics+N-body constrained cosmological simulations of the Local Supercluster region (LSC; about 30/h Mpc around the Virgo cluster), which closely mimic the real Universe within 100 Mpc by imposing constraints from…
The Far Ultraviolet Spectroscopic Explorer (FUSE) has observed over three hundred fifty sightlines to extragalactic targets. About one hundred fifty of these are of sufficient quality to measure OVI absorption in and near the Milky Way.…
Soon after the first QSO was identified, Gunn & Peterson searched for the expected characteristic absorption trough on the blueward side of Lya in the spectrum of the QSO due to an Intergalactic Medium (IGM). They failed to find it, placing…
Spectra of about 150 early-type stars in the disk of the Milky Way recorded by the Far Ultraviolet Spectroscopic Explorer (FUSE) reveal absorption features from interstellar O VI, a tracer of collisionally ionized gases at temperatures near…
Galaxies are surrounded by extended gaseous halos which store significant fractions of chemical elements. These are syntethized by the stellar populations and later ejected into the circumgalactic medium (CGM) by different mechanism, of…
We report a bimodality in the azimuthal angle ($\Phi$) distribution of gas around galaxies traced by OVI absorption. We present the mean $\Phi$ probability distribution function of 29 HST-imaged OVI absorbing (EW>0.1A) and 24~non-absorbing…
We combine observations of spiral galaxies in the [CII] line at 158 micron, made with the Long Wavelength Spectrometer aboard ISO, with previous data from the Kuiper Airborne Observatory to study the origin of this line, which is the main…
We show that the cosmic star formation rate per comoving volume should exhibit a distinct drop around the reionization redshift, when the HII regions in the intergalactic medium around individual ionizing sources first overlapped. The drop…
The circumgalactic medium (CGM) of nearby star-forming galaxies shows clear indications of OVI absorption accompanied by little to no detectable NV absorption. This unusual spectral signature, accompanied by highly non-uniform absorption…
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…
To gain insight into four highly ionized high-velocity clouds (HVCs) discovered by Sembach et al. (1999), we have analyzed data from the Hubble Space Telescope (HST) and Far Ultraviolet Spectroscopic Explorer (FUSE) for the PKS 2155-304 and…
We examine how HI and metal absorption lines within low-redshift galaxy halos trace the dynamical state of circumgalactic gas, using cosmological hydrodynamic simulations that include a well-vetted heuristic model for galactic outflows. We…