Related papers: Bringing Simulation and Observation Together to Be…
The HI and CO components of the interstellar medium (ISM) are usually used to derive the dynamical mass M_dyn of nearby galaxies. Both components become too faint to be used as a tracer in observations of high-redshift galaxies. In those…
We present a method for modelling star-forming clouds that combines two different models of the thermal evolution of the interstellar medium (ISM). In the combined model, where the densities are low enough that at least some part of the…
The absorption by neutral hydrogen in the intergalactic medium (IGM) produces the Ly$\alpha$ forest in the spectra of quasars. The Ly$\alpha$ forest absorbers have a broad distribution of neutral hydrogen column density $N_{\rm HI}$ and…
We develop a new method to constrain the physical conditions in the cool (~10^4 K) circumgalactic medium (CGM) from measurements of ionic column densities, by assuming that the cool CGM spans a large range of gas densities and that small…
This is the first in a series of three papers describing a project with the Cosmic Origins Spectrograph on the Hubble Space Telescope to measure abundances of the neutral interstellar medium (ISM) in a sample of 9 nearby star-forming…
We use numerical simulations of structure formation in a Cold Dark Matter model to predict the absorption lines in the soft X-rays produced by heavy elements in the shock-heated intergalactic medium at low redshift. The simulation…
Sub-millimeter emission lines produced by the interstellar medium (ISM) are strong tracers of star formation and are some of the main targets of line intensity mapping (LIM) surveys. In this work we present an empirical multi-line emission…
We describe techniques for comparing spectra extracted from cosmological simulations and observational data, using the same methodology to link Lyman-alpha properties derived from the simulations with properties derived from observational…
In a hierarchical cosmogony present-day galaxies build up by continuous merging of smaller structures. At a redshift of three the matter content of a typical present-day galaxy is split into about ten individual protogalactic clumps.…
We present a detailed study of the hydrogen density distribution in the local interstellar medium (ISM) using the X-ray absorption technique. Hydrogen column densities were precisely measured by fitting X-ray spectra from coronal sources…
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…
About half of the expected total baryon budget in the local Universe is `missing'. Hydrodynamical simulations suggest that most of the missing baryons are located in a mildly overdense, warm-hot intergalactic medium (WHIM), which is…
We present a high resolution (R~500) X-ray spectrum of the bright quasar H1821+643 (z=0.297), obtained in a 470 ksec Chandra observation. We search for X-ray absorption by highly ionized metal species, OVII and OVIII in particular, at the…
To explore the ionization conditions in highly-ionized absorbers at high redshift we have studied in detail two intervening OVI absorbers at z=2 towards the quasar PKS1448-232, based on high (R=75,000) and intermediate (R=45,000) resolution…
To probe the distribution and physical characteristics of interstellar gas at temperatures T ~ 3e5 K in the disk of the Milky Way, we have used the Far Ultraviolet Spectroscopic Explorer (FUSE) to observe absorption lines of OVI toward 148…
We report on the detection of a population of weak metal-line absorbers in the halo or nearby intergalactic environment of the Milky Way. Using high-resolution ultraviolet absorption-line spectra of bright QSOs obtained with the Space…
We use a high-resolution cosmological simulation that includes hydrodynamics, multiphase star formation, and galactic winds to predict the distribution of metal line emission at z~0 from the intergalactic medium (IGM). We focus on two…
Determining the clumpiness of matter around galaxies is pivotal to a full understanding of the spatially inhomogeneous, multi-phase gas in the circumgalactic medium (CGM). We combine high spatially resolved 3D observations with…
We study the dependence of column densities derived from absorption lines on the spatial distribution of the ions in an absorber. In particular, we investigate four varieties of coverage by the absorber of the background source: the…
During the past decade or so, measurements of Galactic HI absorption using VLBI against extra-galactic sources, as well as multi-epoch observatios in pulsar directions, have detected small-scale transverse variations corresponding to tens…