Research
I have a physics degree from the University of California, San Diego, and
worked as a member of David Tytler's observational cosmology group from
2006-2009.
I have focused previously on studying CIV and MgII metal absorption systems in
pairs of QSOs, by comparing the distribution of absorbers in the spectra of
QSOs which are near to each other (separated by roughly a megaparsec at a
redshift of two). We have found that the probability of detecting absorption
within 500 km/sec of a detection in the partner QSO is at least 50% for
co-moving sightline separations of less than 100 kpc, and drops off rapidly to
8% around 300 kpc (and to less than 1% beyond a megaparsec). An individual
absorbing halo is rarely detected in multiple sightlines. Instead, the
correlation is driven primarily by the metals distributed around galaxies and
by galaxy clustering on megaparsec scale.
This work enabled us to place limits on the amount of gas flowing out of
galaxies, and to predict the shape and lifetime of QSO ultraviolet emission.
I have also been searching for deuterium in QSO spectra to improve estimates
of the primordial deuterium to hydrogen ratio, to check estimates generated
through Big Band nucleosyhthesis models and measurements of the cosmic
microwave background.
I am leading another project studying the effect of QSO on nearby gas, and
have found that absorption lines near to QSO are wider than those detected
further away, by two km/sec. This effect is believed to be due to a
combination of increased heating and larger gas velocities, and is being
modeled through computer simulations.
I have observed on the Shane three-meter telescope and the Nickel 40-inch
telescope at Lick Observatory, and worked as a remote observer on the Keck
Observatory telescopes, for research purposes and to support educational
programs.
I have begun my graduate studies as a member of the
extragalactic group. My research committee consists of Anatoly Klypin (chair)
and Nicole Vogt. I plan on divding my time between coursework, TA duties, and
contributing to the research projects of the group, as well as conducting
projects of my own.
Teaching
I am one of the TAs for Jon Holtzman's Atronomy 110G course, sections M04, M05
and M06 Fall 2009. I teach lab Tuesday 3:30-5:30 and Wednesday 2:30-4:30.
Office hours TBD.
Publications
Metal Absorption Systems in Spectra of Pairs of QSOs: How Absorbers Cluster
Around QSOs and Other Absorbers
David Tytler, Mark Gleed, Carl Melis, Angela Chapman, David Kirkman, Dan Lubin,
Pascal Paschos, Tridivesh Jena, & Arlin P.S. Crotts
2008, MNRAS, 392, 1539
