Related papers: Probing the OVI forest
We present HST/COS high S/N observations of the z = 0.32566 multi-phase absorber towards 3C263. The COS data shows absorption from H I, O VI, C III, N III, Si III and C II. The Ne VIII in this absorber is detected in the FUSE spectrum. The…
We present images and spectroscopy of objects close to the sightline of Q2302+029 in order to search for galaxies responsible for the remarkable z=0.7 high-ionization absorption line system found by Jannuzi et al (1996). This system shows…
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…
Absorption spectroscopy of gravitationally lensed quasars (GLQs) enables study of spatial variations in the interstellar and/or circumgalactic medium of foreground galaxies. We report observations of 4 GLQs, each with two images separated…
We present a direct measurement of the metallicity distribution function for the high redshift intergalactic medium. We determine the shape of this function using survival statistics, which account for both detections and non-detections of…
To detect a warm-hot intergalactic medium associated with the large-scale structure of the universe, we observed a quasar behind the Virgo cluster with XMM-Newton. With a net exposure time of 54 ks, we marginally detected an OVIII K alpha…
We present a survey of NV and OVI (and where available CIV) in the Galactic halo, using data from the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Hubble Space Telescope (HST) along 34 sightlines. These ions are usually produced in…
Galaxy evolution is driven by star formation and stellar feedback on scales unresolved by current high-resolution cosmological simulations, requiring robust subgrid models. However, these models remain degenerate, often calibrated primarily…
ISO has enabled far-infrared spectroscopy of a variety of galaxies. Using the [CII] (158 micron) and [OI](63 micron) lines, we can characterize the physical conditions in the star-forming ISM. These observations also form the basis of our…
Far-infrared (FIR) emission lines are a powerful tool to investigate the properties of the interstellar medium, especially in high-redshift galaxies, where ALMA observations have provided unprecedented information. Interpreting such data…
High resolution FUSE and STIS observations of the bright QSO HE 0226-4110 (zem = 0.495) reveal the presence of a multi-phase absorption line system at zabs(O VI) = 0.20701 containing absorption from H I (Ly alpha to Ly theta), C III, O III,…
We present optical spectroscopy of projected QSO pairs to investigate the MgII and the CIV absorption features imprinted on the spectrum of the background object by the gaseous halo surrounding the foreground QSO. We observed 13 projected…
We study ultraviolet HI and metal line transitions in the circumgalactic medium (CGM) of 15 massive, quenched luminous red galaxies (LRGs) at redshift $z\sim 0.5$ and with impact parameters up to 400 kpc. We selected 8 of LRG-CGM systems to…
We study the internal structure of the Circum-Galactic Medium (CGM), using 29 spectra of 13 gravitationally lensed quasars with image separation angles of a few arcseconds, which correspond to 100 pc to 10 kpc in physical distances. After…
The neutral intergalactic medium above redshift 6 is opaque to ionizing radiation, therefore one needs indirect measurements of the escape fraction of ionizing photons from galaxies of this epoch. Low-ionization state absorption lines are a…
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…
We examine recent measurements of the z~2.5 intergalactic medium (IGM) which constrain the HI frequency distribution f(N) and the mean free path MFP to ionizing radiation. We argue that line-blending and the clustering of strong…
We have conducted the first survey for Oxygen VI $\lambda\lambda 1032,1038$ absorption lines in QSO spectra. We used medium resolution ($R \approx 1300$) high signal-to-noise ($\approx 20$) Faint Object Spectrograph spectra of 11 QSOs…
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…
We estimate the He II to H I column density ratio, \eta = N(He II)/N(H I), in the intergalactic medium towards the high redshift (z_{em} = 2.885) bright quasar QSO HE 2347-4342 using Voigt-profile fitting of the H I transitions in the Lyman…