报告题目：Identifying ultra-compact binary pulsar from long-term and short-term timing data

　　报 告 人：Prof. Gong Biping（华中科技大学龚碧平教授）

　　报告时间：2015年5月27日（星期三） 上午11：00

　　报告地点：台本部110会议室

　　 摘 要 ： PSR B0919+06 have displayed interesting timing  behaviour. The long-term timing  of it  shows quasi-periodicity of 600 days and 10 years respectively. And  in short-term, the  single pulse observation of this pulsar exhibits occasional  change of arrival time  of amplitude of a few micro seconds. Fitting the long-term effect by the geodetic precession of pulsar spin axis, we predict that PSR 0919+06 is a binary pulsar of orbital period of 13.6min and a companion mass of  0.1 sun mass. To test this prediction, we have single-pulse observation at the Arecibo telescope for 2.4hr, which should  cover several orbital periods. In the data, the shifts of quasi-periods of 5-22min are shown. Such a short-term effect is further simulated by the strong tide force of the pulsar on its  companion, a  white dwarf star. Hence, PSR B919+06 is an ultra-compact binary of orbital period of 14.3 min exhibiting quasi-period of 5-22 min in arrival time.

　　联 系 人：黄春苹 0991-3689050