本文章最後由 iheby 於 2016-10-31 00:38 編輯
作為測試廣義相對論案例的繞攏雙黑洞系統OJ287 @香港中文大學物理系
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
地點：香港中文大學 科學館L2演講廰
講者：Prof. Mauri VALTONEN (Department of Physics and Astronomy University of Turku, Finland)
語言：英語
免費會議，歡迎參加
中國五百米孔徑球面射電望遠鏡巡天量測計劃之近期展望 @香港中文大學物理系
Colloquium:- A FAST Drift Scan Survey - The Immediate Prospect of FAST
With the blessing of the nation's president, the Five-hundred-meter Aperture Spherical radio Telescope (FAST) ended its construction phase with much fanfare on Sep. 25, 2016.
Tremendous pressure and somewhat unrealistic expectation accompany the system testing and commissioning currently underway. The frontiers of radio astronomy have clearly shifted to interferometers, e.g. ALMA and SKA, both of which are orders of magnitude higher in terms of actual cost and user base. Our initial plan for commensal drift scan surveys to utilize the unique advantages of FAST.
The most efficient surveying mode of FAST will be the here proposed drift-scan survey, which aims to obtain pulsar, HI galaxies, Galactic ISM, radio transients (Fast Radio Bursts in particular), and SETI data streams simultaneously. Such a comprehensive survey (in commensal mode) has not been accomplished for other major facilities. I will discuss the challenges in implementing such a survey and quantify its potentials.
時間：2016.11.11(五) 16:00 ~ 17:00
地點：香港中文大學 科學館L2演講廰
講者：李菂 博士 Dr. Di LI (中國科學院國家天文台 射電天文研究部)
語言：英語
免費會議，歡迎參加
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