相关论文: SOAR Imaging of sub-Damped Lyman-Alpha Systems at …

We present results from a search for galaxies that give rise to damped Lyman alpha (DLA), subDLA, and Lyman limit system (LLS) absorption at redshifts 0.1 ~< z ~< 1 in the spectra of background quasars. The sample was formed from a larger…

We have obtained very deep near-infrared images in the fields of 10 QSOs whose spectra contain damped Lyman-alpha absorption (DLA) systems with 1.7<z_abs <2.5. The main aim of our investigation is to provide new constraints on the…

We present new imaging and spectroscopic observations of the fields of five QSOs with very strong intervening CaII absorption systems at redshifts z<0.5 selected from the Sloan Digital Sky Survey. Recent studies of these very rare absorbers…

We present a sample of 33 damped Lyman alpha systems (DLAs) discovered in the Sloan Digital Sky Survey (SDSS) whose absorption redshifts (z_abs) are within 6000 km/s of the QSO's systemic redshift (z_sys). Our sample is based on 731 2.5 <…

We investigate Damped Ly-alpha absorbing galaxies (DLA galaxies) at low redshifts z<1 in the hierarchical structure formation scenario to clarify the nature of DLA galaxies because observational data of such galaxies mainly at low redshifts…

To search for low-redshift damped Lyman-alpha (DLA) and sub-DLA quasar absorbers, we have conducted a 21cm absorption survey of radio-loud quasars at small impact parameters to foreground galaxies selected from the Sloan Digital Sky Survey…

We have identified galaxies near two quasars which are at the redshift of damped Lyman-alpha (DLA) systems in the UV spectra of the quasars. Both galaxies are actively forming stars. One galaxy has a luminosity close to the break in the…

We present optical and near-infrared ground-based imaging results on four low-redshift damped Ly-alpha (DLA) galaxies. The corresponding DLA systems were discovered in our HST spectroscopic surveys for DLA lines in known strong MgII…

We report new HST and ground-based observations of a damped Lyman-alpha absorption system toward the QSO 0850+4400. The redshift of the absorption system is z = 0.163770 and the neutral hydrogen column density of the absorption system is…

Images of five QSO fields containing six damped Lyman alpha (DLA) systems at redshifts 0.09<z<0.53 are presented. Identifications for the DLA galaxies giving rise to the DLA systems are made. The observed and modeled characteristics of the…

We study the nature of damped Lya absorption (DLA) systems at z<=1 using a sample of 11 DLA galaxies, for which accurate redshift measurements are available. We demonstrate that the precision of photometric redshifts is sufficient for…

We have carried out a high angular resolution near-infrared imaging study of the fields of 6 quasars with 7 strong absorption line systems at z < 0.5, using the Hokupa'a adaptive optics system and the QUIRC near-infrared camera on the…

We present initial results from a Magellan telescope program to image galaxies that give rise to damped Lyman absorbers (DLAs) at 1.63 < z_DLA < 2.37. Our program differs from previous efforts in that we target quasars with intervening…

Detailed studies of Damped and sub-Damped Lyman-alpha systems (DLA), the galaxies probed by the absorption they produce in the spectra of background quasars, rely on identifying the galaxy responsible for the absorber with more traditional…

The nature of the galaxies that give rise to absorption lines, such as damped Lyman-alpha systems (DLAs) or strong MgII lines, in quasar spectra is difficult to investigate in emission. Taking advantage of the total absorption of the QSO…

We are exploring the connection between damped Ly-alpha absorbers (DLAs) and Lyman break galaxies (LBGs) using deep -- (5sigma)=26 m_{AB}-- broad band imaging (UBVI) of four wide fields (0.25 sq. deg. each) obtained at the Kitt Peak 4-m…

We present the study of a sample of nine QSO fields, with damped-Ly-alpha (DLA) or sub-DLA systems at z~0.6, observed with the X-Shooter spectrograph at the Very Large Telescope. By suitably positioning the X-Shooter slit based on high…

We search for galaxy counterparts to damped Lyman-alpha absorbers (DLAs) at z>2 towards nine quasars, which have 14 DLAs and 8 sub-DLAs in their spectra. We use integral field spectroscopy to search for Ly-alpha emission line objects at the…

We report {\it HST} COS spectroscopy of 10 quasars with foreground star-forming galaxies at 0.02$<$$z$$<$ 0.14 within impact parameters of $\sim$1-7 kpc. We detect damped/sub-damped Ly$\alpha$ absorption in 100$\%$ of cases where no…

With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar's environment in absorption. We search 149 moderate resolution background quasar spectra, from Gemini, Keck, the MMT,…