Search Publications
Black hole masses from reverberation mapping
Peterson, Bradley M.; Bentz, Misty C.
We review briefly how black hole masses are measured directly using reverberation mapping and indirectly through scaling relationships based on reverberation results, in particular through broad-line region radius-luminosity relationships. We discuss the nature and origin of uncertainties in these measurements, and outline current and future effor…
Stratification in the broad line region of AGN: The two-component model
Bon, E.; Popović, L. Č.; Ilić, D. +1 more
Here we present our investigation of the kinematic structure of the broad emission line region (BLR) in a sample of 14 single-peaked Active Galactic Nuclei (AGN), which have been previously observed in the X-ray (Fe Kα line) and where, according to the X-ray emission, a disk geometry is expected. To explain the BLR complex structure we apply a two…
QSO extended emission-line regions
Fu, Hai; Stockton, Alan; Canalizo, Gabriela
Extended emission-line regions (EELRs) on scales of a few tens of kpc are found around a substantial fraction of steep-spectrum radio-loud QSOs. In most cases, at least at low redshifts, the distribution of this gas seems to be uncorrelated with either the stellar distribution in the host galaxy or the radio structure. The origin of the gas and th…
Luminosity functions and star formation rates at z ∼ 6 10: Galaxy buildup in the reionization age
Bouwens, Rychard; Illingworth, Garth
HST ACS and NICMOS data are now of sufficient depth and areal coverage to place strong constraints on the formation and evolution of galaxies during the first 1-2 Gyrs of the universe. Of particular interest are galaxies at z ∼ 6 since they represent the earliest epoch accessible to current high-efficiency optical instrumentation. To this end, we …
Star forming galaxies at z ≈ 6 and reionization
Ellis, Richard; Bunker, Andrew; Lacy, Mark +3 more
We determine the abundance of i'-band drop-outs in the HST/ACS GOODS surveys and the Hubble Ultra Deep Field (UDF). The majority of these sources are likely to be z ≈ 6 galaxies whose flux decrement between the F775W i'-band and F850LP z'-band arises from Lyman- α absorption. We have shown with Keck/DEIMOS and Gemini/GMOS spectroscopy that this te…
Star formation in QSO host galaxies
Lacy, Mark; Stockton, Alan; Canalizo, Gabriela +1 more
Many of the conditions that are necessary for starbursts appear to be important in the triggering of QSOs. However, it is still debatable whether starbursts are ubiquitously present in galaxies harboring QSOs. In this paper we review our current knowledge from observations of the role of starbursts in different types of QSOs. Post-starburst stella…
Searching for the sources responsible for cosmic reionization: Probing the redshift range 7 < z < 10 and beyond
Stark, Daniel P.; Ellis, Richard S.
We review recent observations that suggest that the global star formation rate density of UV-bright galaxies is declining monotonically with redshift over 3 < z < 7 and illustrate the challenges that a continuation of this decline poses in explaining the assembled stellar mass in several z ∼ 6 galaxies deduced from recent Spitzer data. A pla…
Morphology and kinematics of the ionised gas in early-type galaxies
Bacon, Roland; Krajnović, Davor; Emsellem, Eric +10 more
We present results of our ongoing study of the morphology and kinematics of the ionised gas in 48 representative nearby elliptical and lenticular galaxies using the SAURON integral-field spectrograph on the 4.2m William Herschel Telescope. Making use of a recently developed technique, emission is detected in 75% of the galaxies. The ionised-gas di…
Did galaxy assembly and supermassive black-hole growth go hand-in-hand?
Ryan, R. E.; Koekemoer, A. M.; Mobasher, B. +10 more
In this paper, we address whether the growth of supermassive black-holes has kept pace with the process of galaxy assembly. For this purpose, we first searched the Hubble Ultra Deep Field (HUDF) for "tadpole galaxies", which have a knot at one end plus an extended tail. They appear dynamically unrelaxed-presumably early-stage mergers-and make up ∼…
Probing for evolutionary links between local ULIRGs and QSOs using NIR spectroscopy
Lutz, D.; Genzel, R.; Tacconi, L. J. +6 more
We present a study of the dynamical evolution of ultraluminous infrared galaxies (ULIRGs), merging galaxies of infrared luminosity >1012 L⊙. During our very large telescope large program, we have obtained ISAAC near-infrared, high-resolution spectra of 54 ULIRGs (at several merger phases) and 12 local Palomar-Green QSOs, t…