P. S. Smith, G. D. Schmidt, B. T. Jannuzi
The optical properties of the z = 0.435 quasar PKS 1222+216 (4C+21.35) are
summarized since the discovery of impressive gamma-ray activity in this source
by Fermi/LAT. Unlike several other gamma-ray-bright blazars, there appears to
be little connection between optical and gamma-ray activity. Spectropolarimetry
shows this object to be a composite system with optical emission from both a
polarized, variable synchrotron power-law and unpolarized light from a stable
blue continuum source (+broad emission-line region) contributing to the
observed spectrum. Spectrophotometry over a period of about two years does not
detect significant variability in the strong, broad emission lines, despite
large optical continuum variations. This suggests that the relativistic jet has
little influence on the output of the broad emission-line region, possibly
either because the highly beamed continuum ionizes only a small portion of the
line-emitting gas, or the observed non-thermal continuum originates parsecs
downstream from the base of the jet, further away from the central engine than
the broad emission-line region.
View original:
http://arxiv.org/abs/1110.6040
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