Related papers: MgII Absorbers: Halos or Disks?
Spectroscopy of ten quasars obtained with the Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST) is presented. A clustering analysis reveals an excess of nearest neighbor line pairs on velocity scales of 250-750…
We present a study of the cool gas ($\approx 10^4$ K) traced by MgII absorptions around groups of galaxies in the MEGAFLOW survey. Using a combination of two algorithms we blindly identify 32 groups of more than 5 galaxies at $0.3 < z <…
We present initial results of a program to obtain and analyze HST WFPC2 images of galaxies in fields of HST spectroscopic target QSOs. The goal of the program is to investigate how the properties of \lya absorption systems observed in the…
Galaxies are thought to grow through accretion; as less massive galaxies are disrupted and merge over time, their debris results in diffuse, clumpy stellar halos enveloping the central galaxy. Here we present a study of the variation in the…
Gas accreting onto a galaxy will be of low metallicity while halo gas due to a galactic fountain will be of near-solar metallicity. We test these predictions by measuring the metal absorption line properties of halo gas 5 kpc above the…
[Abridged] We examine a sample of 45 Mg II absorption-selected systems over the redshift range 0.4 to 1.4. Mg II and Fe II absorption profiles were observed at a resolution of ~6 km/s with HIRES/Keck. Lyman-alpha and C IV data were measured…
The physical origin of the near-ultraviolet MgII emission remains an under-explored domain, contrary to more typical emission lines detected in the spectra of star-forming galaxies. We explore the nebular and physical properties for a…
Using a large sample of MgII absorbers with 0.4<z<2.2 detected by Nestor et al (2005) in the Early Data Release of the SDSS, we present new constraints on the physical properties of these systems based on two statistical analyses: (i) By…
We examine the properties of two galaxy "halos" at z ~ 0.7 in the TON 153 (z_em = 1.01) quasar field. The first absorber-galaxy pair (G1) is a z = 0.672, L_B = 4.3 L*_B, E/S0 galaxy probed at D = 58 kpc. G1 is associated with a remarkable…
We present results of surveys for high redshift galaxies selected by their having produced detectable Mg~II and Lyman limit absorption in the spectra of background QSOs. We discuss the properties of the absorbing galaxies, the connection…
We present the first result in exploring the gaseous halo and galaxy correlation using the Dark Energy Spectroscopic Instrument (DESI) survey validation data in the Cosmic Evolution Survey (COSMOS) and Hyper Suprime-Cam (HSC) field. We…
The extended hot X-ray emitting gaseous halo of the Milky Way has an optical depth $\sim1$ for the dominant emission lines of \ion{O}{7} and \ion{O}{8}, which are used to infer the halo properties. To improve on halo gas properties, we…
Radio wave propagation can be perturbed by compact ionized gas clumps through plasma lensing, which induces frequency dependent magnification and may distort the observed number counts of background sources. The quasar (QSO) number…
Recent observations have shown that (some) metal line absorption systems in QSO spectra arise from gas in galactic halos with radii much larger than the optical radii of galaxies. We show that the observed galaxy-absorber connections are…
We present a measurement of the mean density profile of Ca II gas around galaxies out to ~ 200 kpc, traced by Fraunhofer's H & K absorption lines. The measurement is based on cross-correlating the positions of about one million foreground…
We combine HI 21cm observations of the Milky Way, M31, and the local galaxy population with QSO absorption-line measurements to geometrically model the three-dimensional distribution of infalling neutral gas clouds (HVCs) in the extended…
We performed multi-band deep imaging of the field around GRB 050730 to identify the host galaxies of intervening absorbers, which consist of a damped Ly{\alpha} absorption (DLA) system at zabs=3.564, a sub-DLA system at zabs=3.022, and…
We present initial results from the \textit{COS and Gemini Mapping the Circumgalactic Medium} (\mbox{CGMCGM} $\equiv$ CGM$^{2}$) survey. The CGM$^{2}$ survey consists of 1689 galaxies, all with high-quality Gemini GMOS spectra, within 1 Mpc…
We present nebular emission associated with 198 strong Mg II absorbers at 0.35 $\le z \le$ 1.1 in the fibre spectra of quasars from the Sloan Digital Sky Survey. Measured [O II] luminosities (L$_{[O II]}$) are typical of sub-L$^{\star}$…
From a sample of 109 candidate Ultra-Strong Mg II (USMgII; having rest equivalent width of Mg II absorption, $W_{2796}>3.0$ Angstrom) systems at z=0.4-0.6, we confirm 27 and identify host galaxies of 20 systems based on associated nebular…