Date post: | 21-Dec-2015 |
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Sites of Particle Acceleration in Quasar Jets
Alan MarscherBoston University
Research Web Page: www.bu.edu/blazars
Jets of Quasars
43 GHz
1 mas = 2.6 pc
Knots require particle acceleration
Spectral energy distribution (SED) reveals very high E component with nearly flat power-law electron energy distribution N(E) as well as another with steeper N(E)
Compact jet: SED of individual knots not defined over broad spectral range, could either be a power law or closer to monoenergetic; polarization generally oblique to jet axis
Emission Regions in an AGN
Issues:
Origin of bright knots: oblique shocks? Something else?
Core of jet seen on VLBI images: site of standing shock, reconnection, or end of flow acceleration?
Rampant particle acceleration many kpc downstream: shocks?
Unbeamed
Beamed
Sketch of Physical Structure of Jet, AGN