Previous
abstract 
Next
abstract
Session 99 - Blazars.
Display session, Thursday, January 16
Metropolitan Ballroom,
Frequent observations of the polarization and flux density of extragalactic variable radio sources are made at 4.8 GHz, 8.0 GHz and 14.5 GHz using the Michigan 26-meter telescope as part of a continuing study of active galactic nuclei. A core group of approximately 65 highly active sources are observed typically once per week at each of the three frequencies, and less frequent measurements are made of an additional 200 objects. Sources are selected with the goals of: testing detailed numerical simulations of the evolution of the radio emitting regions, obtaining broad-band energy distributions (by coordination with simultaneous observations at other wavelengths extending to \gamma-rays) for tests of emission mechanisms, and providing data to complement high resolution VLBI observations. Recent data obtained in this program are available on our web page under URL: http://www.astro.lsa.umich.edu/. Observations for the currently active sources 3C 120, 0528+134, 3C 279, and BL Lac are presented to illustrate how these data are used to study the emitting regions of the objects. Our results continue to support the interpretation of outbursts as shocks propagating in relativistic flows. This work was supported in part by the National Science Foundation under grant AST-9421979 and preceding grants.
