FAST detection of high activity FRB 20220912A
ATel #15733; Yongkun Zhang (NAOC), Jiarui Niu (NAOC), Yi Feng (Zhejiang lab), Weiwei Zhu (NAOC), Bing Zhang (UNLV), Di Li (NAOC), Yuhao Zhu (NAOC), Shuo Cao (YNAO), Chaowei Tsai (NAOC), Dongzi Li (Caltech), Wenfei Yu (SHAO), Heng Xu (PKU), Chunfeng Zhang (NAOC), Kejia Lee (PKU), Chenhui Niu (NAOC), Dejiang Zhou (NAOC), Jinlin Han (NAOC), Lei Qian (NAOC), Weiyang Wang (PKU), Youling Yue (NAOC), Yuanpei Yang (YNU), and FAST FRB Key Science Project
on 31 Oct 2022; 08:59 UT
Credential Certification: Pei Wang (wangpei@nao.cas.cn)
Subjects: Radio, Fast Radio Burst
Triggered by the CHIME discovery ATel#15679, FAST observed FRB 20220912A for 30 minutes on October 28, 2022, with the central beam of the FAST 19-beam L-band array pointing to RA = 23h09h04.9s, DEC = +48d42m25.4s, the localization given by the Deep Synoptic Array (DSA-110) ATel#15716.
In this observation, FAST detected more than 180 bursts with SNR > 7 in L-band (1000-1500 MHz), implying an event rate close to 400/hr. No significant period was found. We measured the polarization property of these bursts. The rotation measure (RM) values are the same as reported by CHIME ATel#
15679, with small fluctuation around 0 rad/m^2. Consistent with GBT results ATel#
15723, most bursts have nearly 100% linear polarization. Many bursts have minor circular polarization, typically <20%, with the highest fraction reaching 40%.
Considering that this FRB was found on September 12 and is still so active a month later, this FRB has the potential to be the most active (event rate and active time) FRB. We suggest continuous multi-band observations to cover its activity.
