Related papers: The Last Eight-Billion Years of Intergalactic CIV …

The C III] 1907,1909 emission doublet has been proposed as an alternative to Lyman-alpha in redshift confirmations of galaxies at z > 6 since it is not attenuated by the largely neutral intergalactic medium at these redshifts and is…

An extremely careful separation of the weak metal-line systems relating to the Lyman forest absorbers into individual ``single-phase ionization'' components with accurate parameters has yielded a large sample in the wide redshift range 1.9…

Using 190,000 spectra from the seventeenth data release of the Sloan Digital Sky Survey, we investigate the ultraviolet emission line properties in z=2 quasars. Specifically, we quantify how the shape of CIV 1549A and the equivalent width…

Using the MEGAFLOW survey, which consists of a combination of MUSE and UVES observations of 22 quasar fields selected to contain strong MgII absorbers, we measure covering fractions of CIV and MgII as a function of impact parameter $b$…

We present new high-precision measurements of the opacity of the intergalactic and circumgalactic medium (IGM, CGM) at <z>=2.4. Using Voigt profile fits to the full Lyman alpha and Lyman beta forests in 15 high-resolution high-S/N spectra…

Using hydrodynamic simulations we compute the metal enrichment history of the intergalactic medium (IGM). We show that galactic superwind (GSW) feedback can transport metals to the IGM and that the properties of simulated metal absorbers…

This paper presents ionization-corrected measurements of the carbon abundance in intergalactic gas at 4.0 < z < 4.5, using spectra of three bright quasars obtained with the MIKE spectrograph on Magellan. By measuring the CIV strength in a…

We present detailed photoionization models of well aligned optically thin C III absorption components at $2.1 < z < 3.4$. Using our models we estimate density ($n_{\rm \tiny H}$), metallicity ($[C/H]$), total hydrogen column density and…

We present a survey for metal absorption systems traced by neutral oxygen over $3.2 < z < 6.5$. Our survey uses Keck/ESI and VLT/X-Shooter spectra of 199 QSOs with redshifts up to 6.6. In total we detect 74 O I absorbers, of which 57 are…

Absorbers seen in the spectrum of background quasars are a unique tool to select HI-rich galaxies at all redshifts. In turns, these allow to determine the cosmological evolution of the HI gas, Omega_HI+HeII, a possible indicator of gas…

We present the results of a survey for CaII 3934,3969 absorption-line systems culled from ~ 95,000 Sloan Digital Sky Survey (SDSS) Data Release 7 and Data Release 9 quasar spectra. With 435 doublets identified in the catalog, this list is…

(Abridged) We report the discovery of extended CIV gaseous envelopes around galaxies of a wide range of luminosity and morphological type. First, we show that CIV absorption systems are strongly clustered around galaxies on velocity scales…

We use observations of spatially-aligned C II, C IV, Si II, Si IV, and O I absorbers to probe the slope and intensity of the ultraviolet background (UVB) at $z \sim 6$. We accomplish this by comparing observations with predictions from a…

Comparison of six high-redshift quasar spectra obtained with the Large Binocular Telescope with previous observations from the Sloan Digital Sky Survey shows that failure to correctly identify absorption and other problems with accurate…

We investigate the variability of CIV 1549A broad absorption line (BAL) troughs over rest-frame time scales of up to ~7 yr in 14 quasars at redshifts z>2.1. For 9 sources at sufficiently high redshift, we also compare CIV and SiIV 1400A…

We present 0.5-8.0 keV Chandra observations of six bright quasars that represent extrema in quasar emission-line properties -- three quasars each with small and large blueshifts of the CIV emission line with respect to the systemic redshift…

We present measurements of the cross-correlation of the triply-ionized carbon (CIV) forest with quasars using Sloan Digital Sky Survey Data Release 14. The study exploits a large sample of new quasars from the first two years of…

We present tomography of the circum-galactic metal distribution at redshift 1.7 to 4.5 derived from echellete spectroscopy of binary quasars. We find CIV systems at similar redshifts in paired sightlines more often than expected for…

We present two low resolution (R~1300) high signal-to-noise spectra (Wr,lim~50mA) of the quasar CSO 118 (zem=2.97) taken with the Hobby-Eberly Telescope Marcario Low Resolution Spectrograph. We detect eight absorbers selected by the CIV…

We present the results of a large survey of HI, OVI, and CIII absorption lines in the low-redshift (z<0.3) intergalactic medium (IGM). We begin with 171 strong Lyalpha absorption lines (W>80 mA) in 31 AGN sight lines studied with the Hubble…