Related papers: Molecular Hydrogen in the Damped Lyman-alpha Syste…

We report the detections of molecular hydrogen (H$_2$), vibrationally-excited H$_2$ (H$^*_2$), and neutral atomic carbon (CI), in two new afterglow spectra of GRBs\,181020A ($z=2.938$) and 190114A ($z=3.376$), observed with X-shooter at the…

We report results from our mini-survey for molecular hydrogen in eight high redshift damped Lyman-alpha (DLA) systems using the ESO Ultra-violet and Visible Spectrograph on the VLT. In addition, we investigate two systems using ESO public…

We study the dust depletion pattern in eight well separated components of the z=1.973, logN(HI)=20.83, damped Lyman-alpha system toward Q0013-004, four of which have detectable H2 absorption. The apparent correlation between the abundance…

We report the detection of H2 in a zabs= 0.0963 Damped Lyman-{\alpha} (DLA) system towards zem = 0.4716 QSO J1619+3342. This DLA has log N(H I) = 20.55 (0.10), 18.13 < log N(H2) < 18.40, [S/H] = -0.62 (0.13), [Fe/S] = -1.00 (0.17) and the…

We have searched for molecular hydrogen in damped Lyman-alpha (DLA) and sub-DLA systems at z>1.8 using UVES at the VLT. Out of the 33 systems in our sample, 8 have firm and 2 have tentative detections of associated H2 absorption lines.…

We report the detection of H_2, CI, CI*, CI** and Cl I lines in a near Solar-metallicity ([Zn/H]=-0.13) damped Lyman-alpha (DLA) system at z_abs=1.962 observed on the line of sight to the quasar Q 0551-366. The iron-peak elements, X=Fe, Cr…

We have discovered molecular hydrogen in a fourth quasar damped Ly-alpha system (hereafter DLA). The UVES spectrograph on the 8.2m ESO Kueyen telescope has allowed the detection of H2 in gas with low metallicity, Z/Z_solar ~= 10^{-2}, and…

We present the first large, blind and uniformly selected survey for molecular hydrogen (H_2) in damped Lyman alpha systems (DLAs) with moderate-to-high resolution spectra. 86 DLAs were searched for absorption in the many Lyman and Werner…

A new molecular hydrogen cloud is found in the sub-damped Ly-alpha absorber [log N(HI)=19.88+/-0.05] at the redshift z=1.15 toward the bright quasar HE0515-4414 (zem = 1.71). More than 30 absorption features in the Lyman band system of H2…

We present a detailed analysis of a H$_2$-rich, extremely strong intervening Damped Ly-$\alpha$ Absorption system (DLA) at $z_{\rm abs}=2.786$ towards the quasar J$\,$0843+0221, observed with the Ultraviolet and Visual Echelle Spectrograph…

We present the elemental abundance and H2 content measurements of a Damped Lyman-{\alpha} (DLA) system with an extremely large H i column density, log N(H i) (cm-2) = 22.0+/-0.10, at zabs = 3.287 towards the QSO SDSS J 081634+144612. We…

The gamma-ray burst (GRB) afterglows provide an unique opportunity to study the interstellar medium (ISM) of star-forming galaxies at high-redshift. The GRB-DLAs (damped Lyman-$\alpha$ absorbers) contain a large neutral hydrogen column…

We present the current status of ongoing searches for molecular hydrogen in high-redshift (1.8 < zabs <= 4.2) Damped Lyman-alpha systems (DLAs) capitalising on observations performed with the ESO Very Large Telescope (VLT) Ultraviolet and…

In order to interpret H2 (molecular hydrogen) quasar absorption line observations of damped Ly-alpha systems (DLAs) and sub-DLAs, we model their H2 abundance as a function of dust-to-gas ratio, including H2 self-shielding and dust…

To interpret H_2 quasar absorption line observations in Damped Ly-alpha clouds (DLAs), we model the H_2 spatial distribution within a DLA. Based on numerical simulations of disk structures with parameters similar to those derived for such…

Lyman- and Werner-band absorption of molecular hydrogen (H$_2$) is detected in $\sim$50% of low redshift ($z<1$) DLAs/sub-DLAs with $N$(H$_2$) > 10$^{14.4}$ cm$^{-2}$. However the true origin(s) of the H$_2$ bearing gas remain elusive. Here…

We examine the abundance of molecular hydrogen (H2) in the spectra of gamma ray burst afterglows (GRBs). In nearby galaxies H2 traces the cold neutral medium (CNM) and dense molecular star-forming interstellar gas. Though H2 is detected in…

Simulations predict that circumgalactic hydrogen gas surrounding massive ($M_{\rm{halo}}^{z=1}=10^{12}-10^{13}\ M_{\odot}$) galaxies at $z\sim4$ may be predominantly neutral, and could produce damped Ly$\alpha$ absorbers (DLAs) along…

We present a detailed analysis of the H_2 and HD absorption lines detected in the Damped Lyman-alpha (DLA) system at z_abs=2.3377 towards the quasar Q1232+082. We show that this intervening cloud has a covering factor smaller than unity and…

We used HST/STIS to obtain the spectrum of molecular hydrogen associated with the damped Ly$\alpha$ system at $z_{\rm abs}=1.7765$ toward the quasar Q1331+170 at $z_{\rm em}=2.084$. Strong ${\rm H}_2$ absorption was detected, with a total…