Falcke et al.: Low-Luminosity and Radio-Weak Blazars?
Blazars in Low-Luminosity and Radio-Weak AGN?
Heino Falcke, Sera Markoff, & Peter L. Biermann
Max-Planck-Institut für Radioastronomie, Auf den Hügel 69, D-53121 Bonn, Germany
in "Blazar Demographics and Physics", ASP Conf. Ser. Vol. 227,
Eds. P. Padovani & M.C. Urry, p. 56
Typical blazars seem to be associated with FR I and FR II radio
galaxies and radio-loud quasars. However, what happens at lower
powers? Do blazars exist in low-luminosity AGN or do they exist in
radio-quiet AGN? Our recent detection of superluminal motion in a
supposedly radio-quiet Seyfert raises the question whether beaming can
play an important role in some of these objects as well. Moreover,
VLBI observations of nearby low-luminosity AGN reveal compact
flat-spectrum radio cores very similar to those in bright radio-loud
blazars. Furthermore, with the detection of X-ray emission from the
least luminous AGN we can study, Sgr A* in the Galactic Center, this
source seems to be dominated entirely by non-thermal emission -- like
in BL Lacs. The same may be true for some X-ray binaries in the
Low/Hard-state. Inclusion of low-power radio jets into the overall
picture provides some clues for what type of accretion is important,
what the power, radiative efficiency and matter-content of jets is,
and what mechanism could be responsible for making jets radio-loud. We
specifically discuss whether proton-proton collisions in a hot
accretion flow could provide the switch for the radio-dichotomy.
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Questions: Heino Falcke, firstname.lastname@example.org