English
Related papers

Related papers: MgII absorption systems and their neighbouring gal…

200 papers

We have made a statistically complete, unbiased survey of C IV systems toward a region of high QSO density near the South Galactic Pole using 25 lines of sight spanning $1.5<z<2.8$. Such a survey makes an excellent probe of large-scale…

Astrophysics · Physics 2015-06-24 G. M. Williger , C. Hazard , J. A. Baldwin , R. G. McMahon

We examine halo gas cross sections and covering fractions, f_c, of intermediate redshift MgII absorption selected galaxies. We computed statistical absorber halo radii, R_x, using current values of dN/dz and Schechter luminosity function…

Astrophysics · Physics 2009-06-23 G. G. Kacprzak , C. W. Churchill , C. C. Steidel , M. T. Murphy

The four known molecular absorption line systems at redshifts z$=$0.25--0.89 are discussed. Two of the systems originate in the galaxy hosting the `background' AGN, while in two cases the absorption occurs in truely intervening galaxies.…

Astrophysics · Physics 2007-05-23 Tommy Wiklind , Francoise Combes

We report a bimodality in the azimuthal angle distribution of gas around galaxies as traced by MgII absorption: Halo gas prefers to exist near the projected galaxy major and minor axes. The bimodality is demonstrated by computing the mean…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 G. G. Kacprzak , C. W. Churchill , N. M. Nielsen

We revisit echelle spectra (spectral resolution R ~ 40000) of 8 Gamma-Ray Burst afterglows to obtain the incidence (dN/dz) of weak intervening Mg II systems at a mean redshift of <z> = 1.5. We show that dN/dz of systems having restframe…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-18 Nicolas Tejos , Sebastian Lopez , J. Xavier Prochaska , Joshua S. Bloom , Hsiao-Wen Chen , Miroslava Dessauges-Zavadsky , Maria J. Maureira

The physical conditions of the circumgalactic medium are probed by intervening absorption-line systems in the spectrum of background quasi-stellar objects out to the epoch of cosmic reionization. A correlation between the ionization state…

We combine high-resolution ALMA and HST/CANDELS observations of 20 submillimeter galaxies (SMGs) predominantly from the AS2UDS survey at z~2 with bright rest-frame optical counterparts (Ks < 22.9) to investigate the resolved structural…

We present a catalog of intervening MgII quasar absorption-line systems in the redshift interval 0.36 <= z <= 2.28. The catalog was built from Sloan Digital Sky Survey Data Release Four (SDSS DR4) quasar spectra. Currently, the catalog…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Anna M. Quider , Daniel B. Nestor , David A. Turnshek , Sandhya M. Rao , Eric M. Monier , Anja N. Weyant , Joseph R. Busche

We have constructed samples of low-ionization metal absorption-line systems selected for the strength of their MgII lambda2796 lines from the SDSS EDR. There are 640 absorption systems in our unbiased sample with lambda2796 REW > 1.0 A…

Astrophysics · Physics 2016-01-27 Daniel B. Nestor , Sandhya Rao , David Turnshek , Eric Furst

We present a method for obtaining accurate black hole (BH) mass estimates from the MgII emission line in active galactic nuclei (AGNs). Employing the large database of AGN measurements from the Sloan Digital Sky Survey (SDSS) presented by…

Astrophysics · Physics 2009-11-13 Christopher A. Onken , Juna A. Kollmeier

We present K-band imaging of fields around 30 strong CaII absorption line systems, at 0.7<z<1.1, three of which are confirmed Damped Lyman-alpha systems. A significant excess of galaxies is found within 6"0 (~50kpc) from the absorber…

Astrophysics · Physics 2009-06-23 Paul Hewett , Vivienne Wild

We study the cool gas around a galaxy at z = 0.4729 using Keck/LRIS spectroscopy of a bright (B = 21.7) background galaxy at z = 0.6942 at a transverse distance of 16.5/h_70 kpc. The background galaxy spectrum reveals strong FeII, MgII,…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Kate H. R. Rubin , J. Xavier Prochaska , David C. Koo , Andrew C. Phillips , Benjamin J. Weiner

We report on a survey for strong (rest equivalent width W_r >= 1A), intervening MgII systems along the sightlines to long-duration gamma-ray bursts (GRBs). The GRB spectra which comprise the survey have a heterogeneous mix of resolution and…

The number of strong (equivalent width > 1A) MgII absorbers observed towards Gamma-ray bursts (GRBs) has been found to be statistically larger than the number of strong absorbers towards quasi-stellar objects (QSOs). We formalize this "MgII…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-25 Sharon Rapoport , Christopher A. Onken , J. Stuart B. Wyithe , Brian P. Schmidt , Anders O. Thygesen

We present an investigation of MgII absorbers characterized as single-cloud weak systems at z~1. We measured column densities and Doppler parameters for MgII and FeII in 15 systems found in HIRES/Keck spectra at 6.6 km/s. Using these…

Astrophysics · Physics 2016-08-30 Jane R. Rigby , Jane C. Charlton , Christopher W. Churchill

We have obtained Keck HIRES spectra of three images of the gravitationally lensed QSO 2237+0305 to study low ionization absorption systems and their differences in terms of projected velocity and column density across the lines of sight. We…

Astrophysics · Physics 2009-11-07 M. Rauch , W. L. W. Sargent , T. A. Barlow , R. A. Simcoe

We have studied a sample of 415 associated (z_ab z_em; relative velocity with respect to QSO <3000km/s) Mg II absorption systems with 1.0<=z_ab<=1.86, in the spectra of SDSS DR3 QSOs, to determine the dust content and ionization state in…

We investigate the effect of two important, but oft neglected, factors which can affect the detectability of HI 21-cm absorption in MgII absorption systems: The effect of line-of-sight geometry of the coverage of the background radio flux…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 S. J. Curran

It is widely believed that the cool gas clouds traced by MgII absorption, within a velocity offset of 5000 km/s relative to the background quasar are mostly associated with the quasar itself, whereas the absorbers seen at larger velocity…

Astrophysics of Galaxies · Physics 2017-12-13 S. Mishra , H. Chand , Gopal-Krishna , R. Joshi , Y. A. Shchekinov , T. A. Fatkhullin

Galaxy evolution is thought to be driven in large part by the flow of gas between galaxies and the circumgalactic medium (CGM), a halo of metal-enriched gas extending out to $\gtrsim100$ kpc from each galaxy. Studying the spatial structure…

‹ Prev 1 8 9 10 Next ›