M. Villata, et al. (incl. M. Böttcher,
B. Ragozzine, and K. Uckert),
Astronomy & Astrophysics, 481, L79 (2008)
Aims.
Since the CGRO operation in 1991 - 2000, one of the main issues
on the blazar gamma-ray emission has been its possible correlation
with the low-energy (in particular optical) emission. At this
purpose, the Whole Earth Blazar Telescope (WEBT) consortium has
organized the GLAST-AGILE Support Program (GASP) to provide the
optical-to-radio monitoring data to be compared with the gamma-ray
detections by the AGILE and GLAST satellites. This new WEBT project
started in early September 2007, just before a strong gamma-ray
detection of 0716+714 by AGILE.
Methods.
We present the GAASP-WEBT optical and radio light curves of this
blazar obtained in July - November 2007, around various AGILE
pointings at the source. We also construct NIR-to-UV spectral
energy distributions (SEDs), by assembling GASP-WEBT data
together with UV data from the Swift ToO observations of late
October.
Results.
One of the main findings is the observation of a contemporaneous
optical - radio outburst, which is a rare and interesting
phenomenon in blazars. The shape of the SEDs during the outburst
appears peculiarly wavy because of an optical excess and a
UV drop-and-rise. The optical light curve is well sampled during
the AGILE pointings showing prominent and sharp flares;
cross-correlation analysis with the AGILE data will shed
light on the expected relationship between these flares
and the gamma-ray events.