Prof. Achamveedu Gopakumar
Tata Institute of Fundamental Research Mumbai, India
 

Predicted General Relativity Centenary flare in Blazar OJ287 and its implications

Abstract:

Blazars are active galactic nuclei with strong jets. They tend to exhibit dramatic and unpredictable flux variations, namely outbursts. Certain observed outbursts from an exceptional Blazar OJ287 suggest that it may contain a spinning supermassive black hole binary that spirals in due to the emission of gravitational waves. This deduction is based on the fact that prominent outbursts of OJ287 are inherent in our binary black hole model. Few years ago, detailed General Relativistic modeling allowed us to predict a major optical outburst during November 2015. The outburst did occur within the expected time range, peaking on 5/12/2015. An observational campaign that involved two dozen optical observatories and the SWIFT satellite revealed the presence of a major thermal component in the flare. The timing of this component provided, for the first time,  an accurate measurement for the spin of the primary black hole in a binary. This  accurate measurement opens up the possibility of employing sophisticated  instruments to probe General Relativistic properties of OJ287.