Connection between optical and radio/millimeter flares in blazar OJ287

Abstract

Blazar OJ287 is a unique source in which optical outbursts with double-peak structure have been observed quasi-periodically with a cycle of 12yr. It may be one of the best candidates for searching supermassive black hole binaries. We investigate the connection between its optical and radio/millimeter variations and interpret the emissions in terms of relativistic jet models. Specifically, we make a detailed analysis and model simulation of the optical and radio/mm light curves for the outburst during the period of 1995.8--1996.1. It is shown that the multi-wavelength light curves at optical V-band and radio/mm wavelengths (37, 22, 14.5 and 8 GHz) can be decomposed into 36 individual elementary flares, each of which has a symmetric profile. The elementary flares can be understood to be produced through lighthouse effect due to the helical motion of corresponding superluminal optical/radio knots. Helical motion of superluminal knots should be prevailing in the inner regions of its relativistic jet formed in the magnetosphere of the putative supermassive black hole/accretion disk system. A comprehensive and compatible framework for understanding the entire phenomena in OJ287 is described.