相关论文: Most precise single redshift bound to Delta alpha/…

We used our database of VLT-UVES quasar spectra to build up a sample of 70 Damped Lyman-alpha (DLA) or strong sub-DLA systems with total neutral hydrogen column densities of log N(HI)>20 and redshifts in the range 1.7<z_abs<4.3. For each of…

We present results of our HST Cycle 11 Survey for low-redshift (z<1.65) DLAs in the UV spectra of quasars selected from the SDSS Early Data Release. These quasars have strong intervening MgII-FeII systems which are known signatures of high…

We report new observations of ZnII and CrII absorption lines in 10 damped \lya systems (DLAs), mostly at redshift $z_{abs} \simgt 2.5$ . By combining these results with those from our earlier survey (Pettini et al. 1994) and other recent…

We consider the deconvolution of the thermal and the turbulent profiles for a pair of ions with different atomic weights under the condition that the lines are formed in an absorbing medium with fluctuating density and velocity fields. Our…

We present the observation of a new intermediate redshift damped Lyman-alpha absorption system candidate, discovered in the course of a spectroscopic follow-up for identifying the sources detected in a 150 A wide bandpass UV-imaging survey…

We present an analytic formalism to compute the fluctuating component of the \ion{H}{1} signal and extend it to take into account the effects of partial Lyman-$\alpha$ coupling during the era of cosmic dawn. We use excursion set formalism…

The precision measurements of the strong coupling constant, alphas, and its energy-scale dependence carried out at HERA by the H1 and ZEUS Collaborations are reviewed. An average value of alphas(Mz) = 0.1186 +- 0.0011 (exp.) +- 0.0050 (th.)…

We present 36 spectroscopically confirmed intrinsically UV-faint Ly$\alpha$ emitting galaxies from follow-up observations with Keck/DEIMOS of gravitationally lensed high-redshift candidates. Candidates were selected to be between $5\lesssim…

We have detected narrow HI 21cm and CI absorption at $z \sim 1.4 - 1.6$ towards Q0458$-$020 and Q2337$-$011, and use these lines to test for possible changes in the fine structure constant $\alpha$, the proton-electron mass ratio $\mu$, and…

A new method is presented for recovering the abundances of Damped Ly alpha systems (DLAs) taking into account the effects of dust depletion. For the first time, possible variations of the chemical composition of the dust are taken into…

The mean free path of ionizing photons, $\lambda_{\rm mfp}$, is a critical parameter for modeling the intergalactic medium (IGM) both during and after reionization. We present direct measurements of $\lambda_{\rm mfp}$ from QSO spectra over…

We present a new catalogue of Damped Lyman-$\alpha$ absorbers from SDSS DR16Q, as well as new estimates of their statistical properties. Our estimates are computed with the Gaussian process models presented in Garnett et al. (2017); Ho et…

We investigate the possibility of performing cosmological studies in the redshift range $2.5<z<5$ through suitable extensions of existing and upcoming radio-telescopes like CHIME, HIRAX and FAST. We use the Fisher matrix technique to…

Forthcoming measurements of the line-intensity mapping (LIM) power spectrum (PS) are expected to provide valuable constraints on astrophysical and cosmological quantities. We focus on the [CII] luminosity function (LF) at high redshift,…

We report the serendipitous discovery of two objects close in projection with fairly strong emission lines at long wavelength (~9190 A). One (A) seems not to be hosted by any galaxy brighter than V(555)=27.5, or I(814)=26.7 (Vega-based…

We measure the effective optical depth in the Lyman-alpha (Ly$\alpha$) forest using 40,035 quasar spectra from the Twelfth Data Release (DR12) of the Baryon Oscillation Spectroscopic Survey (BOSS) of SDSS-IV. A rigorous selection based on…

The Galaxy And Mass Assembly (GAMA) survey has obtained spectra of over 230000 targets using the Anglo-Australian Telescope. To homogenise the redshift measurements and improve the reliability, a fully automatic redshift code was developed…

We present a high resolution (FWHM=2.7 km/s), high S/N echelle spectrum for the z = 2.26 QSO J2123-0050 and determine elemental abundances for the z = 2.06 sub-DLA in its line of sight. This high redshift sub-DLA has a complex kinematic…

We present the results from a damped Lya survey of the Sloan Digital Sky Survey, Data Release 3 based on over 500 new damped Lya systems at z>2.2. We measure the HI column density distribution f(N) and its zeroth and first moments (the…

We describe a simple framework to assess the LISA scientific performance (more specifically, its sensitivity and expected parameter-estimation precision for prescribed gravitational-wave signals) under the assumption of failure of one or…