Related papers: The Low-Redshift Lyman Alpha Forest toward 3C 273

We report the GMRT detection of HI 21cm absorption from the $z \sim 3.39$ damped Lyman-$\alpha$ absorber (DLA) towards PKS 0201+113, the highest redshift at which 21cm absorption has been detected in a DLA. The absorption is spread over…

We investigate the properties of the HI Ly-a absorption systems (Ly-a forest) within and around galaxy voids at z<0.1. We find a significant excess (>99% c.l.) of Ly-a systems at the edges of galaxy voids with respect to a random…

We present a study of the galaxy environment of 9 strong HI+CIV absorption line systems ($16.2<{\rm log}(N({\rm HI}))<21.2$) spanning a wide range in metallicity at $z\sim4-5$, using MUSE integral field and X-Shooter spectroscopic data…

We present results from high resolution (R\simeq 28000) spectra of six high- redshift QSOs taken at the ESO NTT telescope that allow the detailed study of the Ly-alpha population in the redshift interval z=2.8-4.1. The typical Doppler…

We develop a prescription for characterizing the strengths of metal lines associated with Lyman-alpha forest absorbers (LYFAs) of a given neutral hydrogen column density N_HI and metallicity [Fe/H]. This Line Observability Index (LOX) is…

We give a comprehensive statistical description of the Lyman-alpha absorption from the intergalactic medium in a hydrodynamic simulation at redshifts 0.1-1.6, the range of redshifts covered by HST spectra of QSOs. We use the ENZO code to…

We present the results of three separate searches for HI 21-cm absorption in a total of twelve damped Lyman-alpha absorption systems (DLAs) and sub-DLAs over the redshift range z = 0.86-3.37. We find no absorption in the five systems for…

Using high S/N STIS echelle spectra (FWHM=7 km/s) of 3C 273, we constrain the metallicities of two Lya clouds in the vicinity of the Virgo cluster. We detect C II, Si II, and Si III absorption lines in the Lya absorber at z = 0.00530.…

Combining a new, increased dataset of 8 QSOs covering the Ly-alpha forest at redshifts 1.5 < z < 3.6 from VLT/UVES observations with previously published results, we have investigated the properties of the Ly-alpha forest at 1.5 < z < 4. We…

We derive the distribution of neutral and ionized gas in high redshift clouds which are optically thick to hydrogen ionizing radiation, using published data on Lyman-limit and Damped Lyman-alpha absorption systems in the redshift range 1.75…

We use the Hubble Space Telescope (HST) archive of ultraviolet (UV) quasar spectroscopy to conduct the first blind survey for damped Ly-alpha absorbers (DLAs) at low redshift (z < 1.6). Our statistical sample includes 463 quasars with…

Spectra of the QSO pair Q0307-195A,B have been obtained in the Ly-alpha Forest (3660 - 3930 A) and C IV (4720 - 4850 A) regions with a FWHM resolution between 0.7 and 0.5 A. 46 lines have been detected in the spectrum of object A while 36…

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 present an analysis of the spatial distribution of gas and galaxies using new X-Shooter observations of $z\sim3-4$ quasars. Adding the X-Shooter data to an existing dataset of high resolution quasar spectroscopy, we use a total sample of…

Narrow-band searches for Lyman alpha emission are an efficient way of identifying star-forming galaxies at high redshifts. We present Keck telescope spectra confirming redshifts z = 5.7 for three objects discovered in the Large Area Lyman…

We study the physical origin of the low-redshift Lyman alpha forest in hydrodynamic simulations of four CDM cosmologies. Our main conclusions are insensitive to the cosmological model but depend on our assumption that the UV background…

We provide new post-COSTAR data on one sightline (Mrk 421) and updated data from another (I Zw 1) from our Hubble Space Telescope (HST) survey of intergalactic Lyman-alpha clouds located along sightlines to four bright quasars passing…

We present a detailed analysis of a very unusual sub-damped Lyman alpha (sub-DLA) system at redshift z=2.304 towards the quasar Q0453-423, based on high signal-to-noise (S/N), high-resolution spectral data obtained with VLT/UVES. With a…

We combine a FUSE sample of OVI absorbers (z < 0.15) with a database of 1.07 million galaxy redshifts to explore the relationship between absorbers and galaxy environments. All 37 absorbers with N(OVI) > 10^{13.2} cm^-2 lie within 800…

We conduct an ultraviolet (HST and FUSE) spectroscopic survey of HI (Lyman lines) and seven metal ions (OVI, NV, CIV, CIII, SiIV, SiIII, FeIII) in the low-redshift intergalactic medium (IGM) at z<0.4. We analyzed 650 Lya absorbers over…