TOO_awehrle_4: Extended Observations of Flaring BL Lac in Nov 2012- Feb 2013
Abstract
We propose to continue our Herschel TOO observations of the flaring eponymous blazar, BL Lac, which is now 2-6 times brighter than it was when we proposed our current TOO observations two months ago, depending on band. BL Lac has now reached 10-to-30-year historical maxima at centimeter, millimeter, submillimeter, and X-ray bands, and is brighter than any previous far infrared observations (ATEL #4557, Wehrle et al.). Our goal is to use 10 weekly Herschel observations with PACS and SPIRE of 15.9 minutes each, (total 2.7 hrs excluding 1.7 hrs time constraint penalty) in combination with VLBI imaging and ground-based millimeter and submillimeter photometry to determine if the far infrared emission is coming from stationary shock regions identified with bright knots in the parsec scale jet. We do this by seeing if the far-infrared emission brightens at the same time as the stationary knots ``light up" in VLBI images from the passage of an energetic disturbance down the jet. In addition, we will continue our evaluation of the physical cause of the flares as either magnetic field line reconnection or turbulence within shocks, and we will derive the physical conditions in the jet by modelling the SEDs as the flare evolves. We will compare the physics of the jet in this TeV blazar to the non-TeV blazar 3C454.3 which we observed with Herschel in November 2010-January 2011 (Wehrle et al. 2012).
- Publication:
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Herschel Space Observatory Proposal
- Pub Date:
- November 2012
- Bibcode:
- 2012hers.prop.2491W