Quasars and the Early Evolution of Massive Galaxies

Michigan State University, East Lansing MI

Investigators

Abstract

AST-0305833 Baldwin Quasar emission lines offer a way to trace the strongly evolving physical conditions in the central regions of young massive galaxies. The gas in the Broad Emission Line Region (BELR) should reveal the chemical evolution in the host galaxy from which it has fallen, and the observed emission lines are not sensitive to the unknown structure of this region. The BELR line strengths also reflect directly the rate of dynamical evolution in the center of the host galaxy. The brightness of these lines means they can be measured precisely even out to quite large redshifts, but they have been hard to interpret. The PI will further check the interpretation methods he has been developing for some years, and will run numerical experiments to determine the best lines to use and to calibrate the use of iron abundances as a chronometer, as well as to understand the true uncertainties in the derived properties of BELRs. Armed with those results, optimized observations will obtain high quality spectra of a carefully selected sample, and derive parameters that can directly reveal early evolution at the centers of massive galaxies. The PI will set up a strong public outreach program through the Abrams Planetarium at Michigan State, using a flashy, continuously running presentation with this research as a background, to inform the thousands of annual visitors about cosmology, the birth of galaxies, and the origin of the chemical elements. With this as a basis it should be possible to produce a more widely distributed planetarium show that will reach an even broader audience.