相关论文: Mg II Selected Absorbers: Ionization structures an…

We present the catalogue of the Mg II absorption systems detected at a high significance level using an automated search algorithm in the spectra of quasars from the twelfth data release of the Sloan Digital Sky Survey. A total of 266,433…

We present a high signal-to-noise high resolution spectrum of the radio-quiet QSO HS1700+6416 (z = 2.72). Analysis of the absorption line systems with metals yields the following results. (1) The dense cluster of C IV doublets at 2.432 <…

We have performed an analysis of over 34,000 MgII doublets at 0.36 < z < 2.29 in Sloan Digital Sky Survey (SDSS) Data-Release 7 quasar spectra; the catalog, advanced data products, and tools for analysis are publicly available. The catalog…

The physical properties of Milky Way Mgii-bearing gas remain poorly constrained due to the saturation of the near-UV doublet. We utilize the weaker Mgii $\lambda\lambda$1239, 1240 doublet from 482 archival HST/COS extragalactic sightlines…

Using Hubble Space Telescope Cosmic Origins Spectrograph observations of 89 QSO sightlines through the Sloan Digital Sky Survey footprint, we study the relationships between C IV absorption systems and the properties of nearby galaxies as…

(Abridged) We present a systematic study of weak intervening CaII absorbers at low redshift (z<0.5), based on the analysis of archival high resolution (R>45,000) optical spectra of 304 quasars and active galactic nuclei observed with…

We interpret observations of intergalactic low ionisation metal absorption systems at redshifts z $\gtrsim$5 in terms of pressure-confined clouds. We find clouds confined by the expected pressure of galactic haloes with masses $11<\log…

We discuss issues concerning the physical nature of intervening MgII quasar absorption systems in light of results from our recent surveys using SDSS EDR QSO spectra and data obtained at the MMT. These surveys indicate an excess of weak…

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 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 characterize the properties of the intergalactic medium (IGM) around a sample of galaxies extracted from state-of-the-art hydrodynamical simulations of structure formation in a cosmological volume of 25 Mpc comoving at $z\sim 2$. The…

We report the detection, based on HST and Keck data, of two peculiar absorbers in the Ly-alpha forest of the quasar PKS 0454+039. These clouds, at redshifts z=0.6248 and 0.9315 respectively, display both MgII and FeII absorption lines in…

We investigate the properties of cold gas at $10^4~\rm K$ around star-forming galaxies at $z~\sim~1$ using Mg II spectra through radiative transfer modeling. We utilize a comprehensive dataset of 624 galaxies from the MAGG and MUDF…

We investigate the origin of intervening cool MgII absorption detected in the spectra of background quasars and the nature of associated galaxies across a broad redshift range of $0.3 \le z \le 1.6$. Using nebular [O II]…

We present results from an imaging and spectroscopic study of four strong MgII absorbers of W(2796) >~ 1 Ang revealed by the afterglow of GRB060418 at z_GRB=1.491. These absorbers, at z=0.603,0.656,1.107 and z_GRB, exhibit large ion…

To study environmental effects on the circumgalactic medium (CGM), we use the samples of redMaPPer galaxy clusters, background quasars and cluster galaxies from the SDSS. With ~82 000 quasar spectra, we detect 197 MgII absorbers in and…

We find multiple Mg II absorption systems at redshift z=1.66, 2.069, and 2.097 in the spatially resolved spectra of the quadruply gravitationally lensed quasar H1413+1143 utilizing the Kyoto tridimensional spectrograph II (Kyoto 3DII)…

We study a sample of 17 z>1.5 absorbers selected based on the presence of strong CI absorption lines in SDSS spectra and observed with the ESO-VLT spectrograph X-shooter. We derive metallicities, depletion onto dust, and extinction by dust,…

We present an empirical connection between cold gas in galactic halos and star formation. Using a sample of more than 8,500 MgII absorbers from SDSS quasar spectra, we report the detection of a 15 sigma correlation between the rest…

(Abridged) We present HIRES/Keck spectra having resolution 6 km/s of Mg II 2796 absorption profiles which arise in the gas associated with 15 identified galaxies over the redshift range 0.5 < z < 0.9. Using non-parametric rank correlation…