Institute for Advanced Study Informal Astrophysics Seminar - DIFFERENT DAY
Testing AGN Evolution Models Through the Comparison of Semi-Analytic Simulations and a Large Observational Data Set
Quasars and radio galaxies display great morphological variety that correlates
with other properties such as spectral slope and luminosity. The unification
theory for radio-loud active galactic nuclei (AGNs) attempts to explain much of
this diversity as arising from anisotropic processes that appear different
because of viewing angle. We are conducting a statistical test of AGN
evolutionary models in the context of the unification theory by comparing
simulated data from semi-analytic models to a large observational catalog. I
will discuss the compilation of the publicly-available radio/optical catalog,
developed for this purpose, from several large sky surveys. The catalog has
over 2 million objects detected at 20 cm, with over 20,000 detected by all
four radio source surveys. Radio color-magnitude-morphology distributions for
this sample show clear structure suggesting strong underlying physical
correlations. Roughly one third of sources have an optical counterpart, and so
can be classified as galaxy (resolved) or quasar (unresolved). Using a subset
of approximately 20,000 sources detected at 92 and 20 cm, as well as optically,
I am developing an AGN sample with well-understood distributions in redshift,
size, luminosity, and spectral index for comparison with the AGN evolution
models as a test of underlying AGN physics and the unification theory. I will
discuss the current state of this project as well as future goals, including
further applications of the catalog and improvements to the semi-analytic
simulations.
Date & Time
January 12, 2010 | 11:30am
Location
Bloomberg Hall Astrophysics LibrarySpeakers
Amy Kimball
Affiliation
University of Washington