Title: Episodic jet ejection in quasars and microquasars

Speaker：Katherine Blundell, Department of Physics, Oxford University

Time： June 12, 2009 (Friday) 2:30pm A601

I bring together evidence for the rapidity with which quasars‘radio synchrotron lobe emission fades and for the intermittency with which jet plasma is ejected from individual quasars and radio galaxies. With these, I affirm the picture presented by Nipoti, Blundell & Binney (2005) that, analogously with episodic jet ejection in microquasars, the radio-loudness of quasars is a function of the epoch at which they are observed. I will present examples of successive episodes of jet activity in quasars, revealed by ICCMB observed with Chandra, where the axis along which jet plasma is launched appears to have precessed.A new model for the weak core radio emission from radio-quiet quasars, that is not any kind of jet ejecta, will also be briefly described.