Adam Bolton
University of Hawaii
Direct Mass Measurements of Massive Elliptical Galaxies
Wednesday, February 6, 2008, 4:00 p.m.
Refreshments at 3:45 p.m.
ABSTRACT
Elliptical galaxies are simple in appearance, but unlike spiral
galaxies, their stars do not follow circular orbits. As a
consequence, the mass-density structure of elliptical galaxies
remains hidden from simple deduction based on Newton's theory of
gravity. In the rare instance that an elliptical galaxy acts as a
"strong gravitational lens" of a more distant object, this difficulty
can be overcome using Einstein's theory of gravity. I will give an
observational overview of elliptical galaxies and a phenomenological
introduction to strong gravitational lensing. I will then describe
recent results on the mass-density structure of elliptical galaxies
from the Sloan Lens ACS Survey, which has assembled the largest-ever
single sample of strong lenses. Pretty pictures and weighty figures
alike will abound.