304 citations · 432 across the 6 of their papers we have counts for
6 papers
In-situ star formation in accretion disk and explanation for correlation between black hole mass and metallicity in AGNs
Xiao Fan, Qingwen Wu
Recent observations show that the metallicity of the broad line region () in active galactic nuclei (AGNs) is solar-to-supersolar, which is positively correlated with…
The Deuterium Abundance at z=0.701 towards QSO 1718+4807
David Tytler, Scott Burles, Limin Lu +3
We present constraints on the deuterium to hydrogen ratio (D/H) in the metal-poor gas cloud at redshift towards QSO 1718+4807. We use new Keck spectra in addition to Hubb…
The Cosmological Baryon Density from the Deuterium Abundance at a redshift z = 3.57
David Tytler, Xiao-ming Fan, Scott Burles
We present a measurement of the deuterium to hydrogen ratio in a quasar absorption system at redshift z = 3.57 towards QSO 1937-1009. We use a two component fit, with redshifts det…
Lick Optical Spectra of Quasar HS 1946+7658 at 10 km/sec Resolution: Lyman-Alpha Forest and Metal Absorption Systems
X. -M. Fan, D. Tytler
We present optical spectra of QSO HS~1946+7658 with either high resolution (FWHM=10 km/s) or high signal to noise ratio (SNR=40-100). We find 113 Lyman alpha and six metal line sys…
Upper Limits on Metals in Quasar Lyman-Alpha Forest Clouds: Absence of C IV Lines in Echelle Spectra
D. Tytler, X. -M. Fan
Recently Lu presented tentative evidence for C IV lines in QSO Lyman-alpha forest systems with strong lines. We have performed a similar search for C IV in our 10 km/sec echelle sp…
Lick Slit Spectra of Thirty-Eight Objective Prism QSO Candidates and Low Metallicity Halo Stars
D. Tytler, X. -M Fan, V. T. Junkkarinen +1
We present Lick Observatory slit spectra of 38 objects which were claimed to have pronounced ultraviolet excess and emission lines by Zhan \& Chen. Most of our spectra have FWHM sp…