7 papers · 1 filter
Mass Loss by X-ray Winds from Active Galactic Nuclei
Doron Chelouche
We consider a sample of type-I active galactic nuclei (AGN) that were observed by Chandra/HETG and resulted in high signal-to-noise grating spectra, which we study in detail. All o…
Deep optical spectroscopy of extended Lyman alpha emission around three radio-quiet z=4.5 quasars
F. Courbin, P. North, A. Eigenbrod +1
We report the first results of a spectroscopic search for Lyman alpha, envelopes around three z=4.5 radio-quiet quasars. Our observational strategy uses the FORS2 spectrograph atta…
On the HI content, dust-to-gas ratio and nature of MgII absorbers
Brice Ménard, Doron Chelouche
We estimate the mean dust-to-gas ratio of MgII absorbers as a function of rest equivalent width W_0 and redshift over the range 0.5<z<1.4. Using the expanded SDSS/HST sample of low…
The Dust Content of Galaxy Clusters
Doron Chelouche, Benjamin P. Koester, David V. Bowen
We report on the detection of reddening toward z ~ 0.2 galaxy clusters. This is measured by correlating the Sloan Digital Sky Survey cluster and quasar catalogs and by comparing th…
On the Connection Between Metal Absorbers and Quasar Nebulae
Doron Chelouche, Brice Ménard, David V. Bowen +1
We establish a simple model for the distribution of cold gas around L* galaxies using a large set of observational constraints on the properties of strong MgII absorber systems. Ou…
Lensing, reddening and extinction effects of MgII absorbers from z=0.4 to z=2
Brice Ménard, Daniel Nestor, David Turnshek +5
Using a sample of almost 7000 strong MgII absorbers with 0.4 < z < 2.2 detected in the SDSS DR4 dataset, we investigate the gravitational lensing and dust extinction effects they i…