New Clues to Jet Launching: The inner disks in radio loud quasars may be
  more stable
  Jet launching in radio loud (RL) quasars is one of the fundamental problems
in astrophysics. Exploring the differences in the inner accretion disk
properties between RL and radio quiet (RQ) quasars might yield helpful clues to
this puzzle. We previously discovered that the shorter term UV/optical
variations of quasars are bluer than the longer term ones, i.e., the so-called
timescale-dependent color variation. This is consistent with the scheme that
the faster variations come from the inner and hotter disk regions, thus
providing a useful tool to map the accretion disk which is otherwise
unresolvable. In this work we compare the UV/optical variations of RL quasars
in SDSS Stripe 82 to those of several RQ samples, including those matched in
redshift-luminosity-black hole mass and/or color-magnitude. We find that while
both RL and RQ populations appear bluer when they brighten, RL quasars
potentially show a weaker/flatter dependence on timescale in their color
variation. We further find that while both RL and RQ populations on average
show similar variation amplitudes at long timescales, fast variations of RL
sources appear weaker/smaller (at timescales of ~ 25 -- 300 days in the
observer's frame), and the difference is more prominent in the g-band than in
the r-band. Inhomogeneous disk simulations can qualitatively reproduce these
observed differences if the inner accretion disk of RL quasars fluctuates less
based on simple toy models. Though the implications are likely model dependent,
the discovery points to an interesting diagram that magnetic fields in RL
quasars may be prospectively stronger and play a key role in both jet launching
and the stabilization of the inner accretion disk.
