邀请人 (Invited by): 胡一鸣

时间 (Time): 星期四，2023 年 8 月 24 日 19:00-20： 00

地点 (Location): 珠海校区天琴中心1416会议室

摘要 (Abstract): 

The continuing survey of the gamma-ray sky by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope has discovered over 300 gamma-ray pulsars in the last 14 years. However, they only account for 10% of the knownpulsars to date. The remaining 90% could simply be below the detection limit of Fermi-LAT. To verify this, I developed novel stacking techniques to analyse Fermi-LAT data beyond the limit of point source sensitivity. A significant detection of a stacked signal over the background was made, which has a pulsarlike spectral index and a characteristic flux well below the Fermi-LAT point source sensitivity. A follow up analysis on these pulsar populations using COMPAS, a rapid binary population synthesis code, is being conducted. Combining existing models of pulsar gamma-ray emission mechanisms and current prescriptions of canonical and binary neutron star evolution in COMPAS, we will be able to provide a best fit model that can describe all the catalogued pulsars observed individually in radio and gamma-ray surveys, as well as the stacking analysis.

主讲人简介 (Speaker's CV): 

Yuzhe Song finished his PhD at the City University of New York and American Museum of Natural History before joining Swinburne University of Technology in Australia as an OzGrav postdoc. His PhD research focused on developing stacking methods to observe faint, undetected sources in gamma-rays using Fermi-LAT data. His current work focuses on population synthesis of pulsars using COMPAS, NBODY simulation of globular clusters, and detecting gamma-ray emission from nearby flare stars.