Fast 3C 279 gamma flares by a merging medium size black hole jet aligned   to the AGN one by tidal torque?
  The shorter-than-Schwarzschild 3C 279 variability flare on June 2015 is very puzzling. Its nature cannot be due to any NS merging nor to a medium sized (hundred million solar mass) BH collapse. Our preliminary model is based on the long-life (a third of a year) merging of a medium size BH (hundred of solar mass) jet spiralling toward the largest AGN one, (billion solar mass), that is dragging by tidal torques the medium small size BH jet along the main AGN 3C 279 one. The tidal torque is aligning both jets toward Earth. The twin overlapping blazars may offer at once a long and a short scale variability consistent with the surprising Fermi discovers. 
Daniele Fargion, Pietro Oliva
astro-ph.HE astro-ph.IM gr-qc