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I present a GHRS archival study of the interstellar absorption lines in the line-of-sight to the HI-rich starburst dwarf galaxy NGC 1705, in the 1170 to 1740A range at ~ 120 km/s resolution. The absorption features arising due to…

Astrophysics · Physics 2009-10-30 M. S. Sahu

We report on detailed Monte Carlo inversion analysis of the Lyman limit system observed at z = 2.917 in the VLT/UVES spectrum of the quasar HE 0940-1050. Metal absorption lines of carbon and silicon in three ionization stages and numerous…

Astrophysics · Physics 2009-11-07 S. A. Levshakov , I. I. Agafonova , M. Centurion , P. Molaro

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…

Astrophysics · Physics 2009-10-30 Uffe Hellsten , Nickolay Y. Gnedin , Jordi Miralda-Escude

We use high-quality, medium-resolution {\it Hubble Space Telescope}/Cosmic Origins Spectrograph (\HST/COS) observations of 82 UV-bright AGN at redshifts $z_{AGN}<0.85$ to construct the largest survey of the low-redshift intergalactic medium…

We determined oxygen and iron abundances of the interstellar medium (ISM) using K-shell (O) and L-shell (Fe) X-ray photo-ionization edges towards Ultra luminous X-ray sources (ULXs). We determine the hydrogen column densities (n_H) towards…

Astrophysics · Physics 2007-05-23 Lisa M. Winter , Richard F. Mushotzky , Christopher S. Reynolds

The intergalactic medium (IGM) comprises all the matter that lies between galaxies. Hosting the vast majority ($\gtrsim 90\%$) of the baryons in the Universe, the IGM is a critical reservoir and probe for cosmology and astrophysics,…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 Nicolas Tejos

Metals in the diffuse, ionized gas at the boundary between the Milky Way's interstellar medium (ISM) and circumgalactic medium (CGM), known as the disk-halo interface (DHI), are valuable tracers of the feedback processes that drive the…

This document describes the publically available numerical code "IGMtransfer", capable of performing intergalactic radiative transfer (RT) of light in the vicinity of the Lyman alpha (Lya) line. Calculating the RT in a (possibly adaptively…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-17 Peter Laursen

In recent years, the autocorrelation of the hydrogen Lyman-{\alpha} forest has been used to observe the baryon acoustic peak at redshift 2 < z < 3.5 using tens of thousands of QSO spectra from the BOSS survey. However, the interstellar…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-20 Yishay Vadai , Dovi Poznanski , Dalya Baron , Peter E. Nugent , David Schlegel

Some recent results are presented about high redshift molecular absorption lines, namely about chemical abundances of elements, and in particular of water and molecular oxygen. Excitation temperatures of several molecules are found lower…

Astrophysics · Physics 2007-05-23 F. Combes , T. Wiklind

The interstellar medium is a complex 'ecosystem' with gas constituents in the atomic, molecular, and ionized states, dust, magnetic fields, and relativistic particles. The Canadian Galactic Plane Survey has imaged these constituents with…

The absorption lines observed in quasar spectra have given us a detailed picture of the intergalactic medium and the metal abundance and kinematics of high redshift galaxies. In this review, we present an introduction to the field, starting…

Astrophysics · Physics 2009-09-25 Jill Bechtold

We have developed a complete model of the hydrogen molecule as part of the spectral simulation code Cloudy. Our goal is to apply this to spectra of high-redshift star-forming regions where H2 absorption is seen, but where few other details…

Astrophysics · Physics 2009-11-13 Gargi Shaw , G. J. Ferland , R. Srianand , N. P. Abel

Nitrogen is one of the most abundant metals in the interstellar medium (ISM), and thus it constitutes an excellent test to study a variety of astrophysical environments, ranging from nova to active galactic nuclei. We present a detailed…

High Energy Astrophysical Phenomena · Physics 2021-05-12 Efrain Gatuzz , Javier A. García , Timothy R. Kallman

The temperature of the diffuse, photo-heated intergalactic medium (IGM) depends on its reionization history because the thermal time scales are long. The widths of the hydrogen Lyman-alpha absorption lines seen in the spectra of distant…

Using the Cosmic Origins Spectrograph aboard the Hubble Space Telescope, we measured the abundances of six ions (C III, C IV, Si III, Si IV, N V, O VI) in the low-redshift (z < 0.4) intergalactic medium and explored C and Si ionization…

Astrophysics of Galaxies · Physics 2015-06-23 J. Michael Shull , Charles. W. Danforth , Evan M. Tilton

A measure of the average depression between Lyman absorption lines in the spectrum of the faint quasar BR1202-0725 ($z_{em}=4.695$) is presented. The relatively high resolution of the spectrum ($\sim 40$ km s$^{-1}$) allows the selection of…

We use the observed number and column-density distributions of intergalactic O VI absorbers to constrain the distribution of metals in the low-redshift intergalactic medium (IGM). In this simple model the metals in the O VI absorbers are…

Astrophysics · Physics 2009-11-10 Jason Tumlinson , Taotao Fang

We present an investigation of the X-ray absorption features predicted by hydrodynamic simulations of radio galaxies interacting with the intracluster medium (ICM) of their host galaxy clusters. We show how these absorption lines can be…

Astrophysics · Physics 2009-11-11 Franziska Koeckert , Christopher S. Reynolds

The reionization of helium is thought to occur at $2.5\lesssim z\lesssim4$, marking the last phase transition and final global heating event of the intergalactic medium (IGM). Since it is driven by rare quasars, helium reionization should…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-13 Saba Etezad-Razavi , Sarah E. I. Bosman , Frederick B. Davies
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