相关论文: Neutral CGM as damped Ly{\alpha} absorbers at high…

The pervasive presence of warm gas in galaxy halos suggests that the circumgalactic medium (CGM) is multiphase in its ionization structure and complex in its kinematics. Some recent state-of-the-art cosmological galaxy simulations predict…

We discuss our recent results on the statistical properties of damped Lyman alpha systems (DLAs) at low redshift (z<1.65) (Rao & Turnshek 2000). Contrary to expectations, we found that the cosmological neutral gas mass density as traced by…

We present basic data and modeling for a survey of the cool, photo-ionized Circum-Galactic Medium (CGM) of low-redshift galaxies using far-UV QSO absorption line probes. This survey consists of "targeted" and "serendipitous" CGM subsamples,…

We report the serendipitous detection of a 0.2 L$^*$, Lyman-$\alpha$ emitting galaxy at redshift 2.5 at an impact parameter of 50 kpc from a bright background QSO sightline. A high-resolution spectrum of the QSO reveals a partial…

We present a systematic investigation of the circumgalactic medium (CGM) within projected distances d<160 kpc of luminous red galaxies (LRGs). The sample comprises 16 intermediate-redshift (z=0.21-0.55) LRGs of stellar mass M_star>1e11…

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 have searched the Sloan Digital Sky Survey Data Release 12 for ghostly Damped Ly$\alpha$ (DLA) systems. These systems, located at the redshift of the quasars, show strong absorption from low-ionization atomic species but reveal no HI…

A comprehensive analysis of 355 high-quality WSRT HI 21-cm line maps of nearby galaxies shows that the properties and incident rate of Damped Lyman-alpha (DLA) absorption systems observed in the spectra of high redshift QSOs are in good…

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 use state-of-the-art cosmological zoom simulations to explore the distribution of neutral gas in and around galaxies that gives rise to high column density \ion{H}{i} \mbox{Ly-$\alpha$} absorption (formally, sub-DLAs and DLAs) in the…

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…

We probe the physical conditions in high redshift galaxies, specifically, the Damped Lyman-alpha Systems (DLAs) using neutral carbon (CI) fine structure lines and molecular hydrogen (H2). We report five new detections of CI and analyze the…

(Abridged) This paper presents an absorption-line study of the multiphase circumgalactic medium (CGM) based on observations of Lya, CII, CIV, SiII, SiIII, and SiIV absorption transitions in the vicinities of 195 galaxies at redshift…

Cold and cool gas (T $\leq 10^4$ K) in the circumgalactic medium (CGM) and its interaction with galaxies remain poorly understood. Simulations predict that cold gas flows into galaxies through cosmic filaments, determining the disk…

We present a study of cold gas absorption from a damped Lyman-$\alpha$ absorber (DLA) at redshift $z_{\rm abs}=1.946$ towards two lensed images of the quasar J144254.78+405535.5 at redshift $z_{\rm QSO} = 2.590$. The physical separation of…

Hydro cosmological simulations reveal that massive galaxies at high redshift are fed by long narrow streams of merging galaxies and a smoother component of cold gas. We post-process seven high-resolution simulated galaxies with radiative…

Chandra X-Ray Observatory (CXO) ACIS-S spectra of three quasars which lie behind three foreground damped Lyman alpha (DLA) absorbers are analyzed in order to attempt to determine the amount of photoelectric absorption due to metals present…

We investigate how damped Lyman-$\alpha$ absorbers (DLAs) at z ~ 2-3, detected in large optical spectroscopic surveys of quasars, trace the population of star-forming galaxies. Building on previous results, we construct a model based on…

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 present the first results from an on-going survey to characterize the circumgalactic medium (CGM) of the massive high-redshift galaxies detected as submillimeter galaxies (SMGs). We constructed a parent sample of 163 SMG-QSO pairs with…