Christopher W. Morgan B.S., 1995, Vanderbilt University M.S., 2004, The Ohio State University

An evening with Christy in Rome - Summer 2001

Research

Gravitationally Lensed Quasars

With my thesis advisor, Chris Kochanek, I am monitoring a set of multiply imaged gravitationally lensed quasar systems using RETROCAM, an optical camera that I built for the MDM 2.4m telescope. One goal of our campaign is to measure the delay between the appearance of the quasar's intrinsic variability in its multiple images. These time delay measurements constrain the Hubble constant and the structure of galaxy halos in the important transition zone between the baryon-dominated inner regions and the dark matter-dominated outer regions. Uncorrelated variability in quasar image fluxes is typically from microlensing by stars in the lens galaxy. We use Monte Carlo analysis of the microlensing signal to measure the physical size of quasar accretion disks. We are also using microlensing in data from the Chandrasekhar X-Ray Observatory to estimate the sizes of X-ray emitting regions in lensed quasars.

Instrumentation

I built an auxiliary-port optical camera for the MDM 2.4m telescope. Here is a link to a paper I wrote for The Astronomical Journal describing RETROCAM.

Here is a link to the RETROCAM website for MDM observers.

Selected Publications

Updated: 24 Sept 2007