2 citations · 4 across the 5 of their papers we have counts for
16 papers · 1 filter
High Velocity Outflows in Quasars
Paola Rodriguez Hidalgo, Fred Hamann, Daniel Nestor +1
High velocity (HV) outflows are an important but poorly understood aspect of quasar/SMBH evolution. Outflows during the luminous accretion phase might play a critical role in "unve…
Quasar Metal Abundances and Host Galaxy Evolution
Fred Hamann, Craig Warner, Matthias Dietrich +1
Quasars signal a unique phase of galaxy evolution -- when massive spheroids are rapidly being assembled, forming stars and growing their central super-massive black holes. Measurem…
Inhomogeneous Absorbers and Derived Column Densities
Bassem M. Sabra, Fred Hamann
We study the dependence of column densities derived from absorption lines on the spatial distribution of the ions in an absorber. In particular, we investigate four varieties of co…
Quasar Elemental Abundances and Host Galaxy Evolution
F. Hamann, M. Dietrich, B. Sabra +1
High redshift quasars mark the locations where massive galaxies are rapidly being assembled and forming stars. There is growing evidence that quasar environments are metal-rich out…
How Massive Are BALQSO Winds?
F. Hamann, B. Sabra, V. Junkkarinen +2
We are involved in a program to derive properties of broad absorption line (BAL) winds in quasars using combined UV and X-ray observations. A major obstacle is large uncertainties…
PG 1254+047: An Intrinsically X-ray Weak, Heavily Absorbed BALQSO?
Bassem M. Sabra, Fred Hamann
We present \textit{Chandra} observations of the radio-quiet Broad Absorption Line (BAL) QSO PG 1254+047. We find that it is a weak X-ray source, with a total of photons m…