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Blazar OJ287 and Its Nano-Hertz GW Emitting Massive BH Binary Central Engine

Speaker:Prof. A. Gopakumar
Affiliation:Tata Institute of Fundamental Research, Mumbai, India
Date:September 6, 2019 (Friday)
September 5, 2019 (Thursday)
Time:11:00 a.m.
Venue:Room 522, 5/F, Chong Yuet Ming Physics Building, HKU
Notice:Date has been updated


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 can be explained by invoking a massive black hole binary as its central engine. 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. A multi-wavelength observational campaign confirmed the occurrence of certain impact flare and the presence of a major thermal component in the flare, as predicted. These observations and subsequent analysis allowed us to establish the possible presence of a spinning supermassive black hole binary that spirals in due to the emission of nano-Hertz gravitational waves in the central engine of OJ287. I will briefly list our on-going efforts that should be interesting to the Event Horizon Telescope consortium and the International Pulsar Timing Array.

Ref: The Unique Blazar OJ 287 and its Massive Binary Black Hole Central Engine Lankeswar Dey, et al. (arXiv:1905.02689)

Coffee and tea will be served 20 minutes prior to the seminar.

Anyone interested is welcome to attend.