Parkes observations for project P1156 semester 2022APRS_06

The discovery of a repeating fast radio burst (FRB) 20200120E localized to a globular cluster (GC) of the nearby (~3.6 Mpc) M81 galaxy challenged our current understanding of FRBs. Its location in an old stellar system and proximity to the Earth (40 times closer than any other extragalactic FRB detected) have profound implications on the origin of FRBs and the number density and luminosity of this type of source. Motivated by this discovery, we propose to search for FRBs targeting at another nearby elliptical galaxy, Centaurus A. Its relative proximity (~3.5 Mpc), combined with its richness in GCs (>1200), makes Centaurus A the best target in the sky for detecting new FRB sources in GCs. Such a targeted survey will allow us to constrain the event rate and luminosity of FRBs from GCs and hence understand their contribution to the cosmological FRB rate and shed new light on the formation of neutron stars in GCs.

本次发现的20200120E重复快速射电暴（FRB）被定位于邻近（约3.6百万秒差距）的M81星系的球状星团（GC）中，该发现对我们当前的快速射电暴认知体系提出了挑战。该暴所处的古老恒星系统环境，以及它与地球的极近距离（比已探测到的其他所有河外快速射电暴近40倍），对快速射电暴的起源、此类源的数密度与光度均具有深远的启示意义。受此发现的启发，我们提出针对另一颗邻近椭圆星系半人马座A开展快速射电暴搜寻工作。半人马座A本身相对较近（约3.5百万秒差距），且拥有超过1200个球状星团，星团数量极为丰富，使其成为天空中探测球状星团内新型快速射电暴源的最佳观测目标。此类靶向巡天将帮助我们限定球状星团内快速射电暴的事件率与光度，进而明晰其对宇宙学尺度快速射电暴总发生率的贡献，并为球状星团内中子星的形成机制提供全新的研究视角。