报告人：龚碧平                   

单位：华中科技大学物理学院

报告时间：2015年4月24日16:00

报告地点：引力中心三楼会议室

报告题目：An ultra-compact binary with orbital period of 14 minutes

报告内容摘要：By the simulation of the longterm  timing noise of PSR B0919+06  with the time delay induced by the precession of pulsar spin axis, we obtain    an 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 as expected. In the data, the shifts of quasi-periods of 5-22min are  shown. With a  mass of ～ 0.1sun mass, the companion star is most probably a White dwarf star, which must experience strong tide force and  hence tide heating from the pulsar with a separation of only ten times the radius of White Dwarf star. The tide effect induced change of orbital  elements, such as  orbital inclination angle, affects the arrival time of the pulsar significantly. Hence, the true binary of orbital period of 14.3  min exhibits quasi-period of 5- 22 min in arrival time. Consequently, PSR B0919+06 is not only the first radio pulsar binary with orbital period less than 90min, but  also the first binary system of compact objects with timing properties dominated by tide force analogous to a planet-satellite system. 

报告人简介：  祖籍湖北云梦，1984年湖北汽车工业学院工业电气自动化专业本科毕业。1989-1992 中山大学引力物理专业硕士研究生。 2001年在香港大学获     得博士学位（天体物理专业）。2001-2005年在南京大学做博士后研究。2005年10月-2006年2月赴法国空间辐射研究所CESR做访问学者。2006 年3月起在华中科技大学任教。研究领域：脉冲星、黑洞