Seminar:- The Inspiralling Black Hole Binary in OJ287 - As A Test Case For General Relativity
At the centenary of Einstein's General Relativity, November 25, 2015, a huge brightening was observed in the quasar OJ287. Based on a binary black hole model, it had been predicted to peak on December 6, but in fact the peak brightness occurred a day earlier. At that time it was one of the brightest objects in the universe. The huge optical outburst confirmed the binary black hole nature of OJ287, and allowed the confirmation of the energy loss to gravitational waves within 2% of the calculated value. Also the dimensionless spin of the primary was determined very accurately, since the exact time of the brightening is spin-sensitive. The value obtained is 0.313 +- 0.01, while the mass of the primary is 1.829 +- 0.001 times 10^10 solar mass. The orbital speed of the secondary exceeds 1/4 of the speed of light at present. This system allows many tests in the strong field General Relativity which are not possible in other known systems.
時間：2016.11.04(五) 16:00 ~ 17:00
講者：Prof. Mauri VALTONEN (Department of Physics and Astronomy University of Turku, Finland)