A radio pulsar phase from SGR J1935+2154 provides clues to the magnetar FRB mechanism

• Published in: Science advances Vol. 9; no. 30; p. eadf6198
• Main Authors: Zhu, Weiwei, Xu, Heng, Zhou, Dejiang, Lin, Lin, Wang, Bojun, Wang, Pei, Zhang, Chunfeng, Niu, Jiarui, Chen, Yutong, Li, Chengkui, Meng, Lingqi, Lee, Kejia, Zhang, Bing, Feng, Yi, Ge, Mingyu, Göğüş, Ersin, Guan, Xing, Han, Jinlin, Jiang, Jinchen, Jiang, Peng, Kouveliotou, Chryssa, Li, Di, Miao, Chenchen, Miao, Xueli, Men, Yunpeng, Niu, Chenghui, Wang, Weiyang, Wang, Zhengli, Xu, Jiangwei, Xu, Renxin, Xue, Mengyao, Yang, Yuanpei, Yu, Wenfei, Yuan, Mao, Yue, Youling, Zhang, Shuangnan, Zhang, Yongkun
• Format: Journal Article
• Language: English
• Published: United States 28.07.2023
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.adf6198

The megajansky radio burst, FRB 20200428, and other bright radio bursts detected from the Galactic source SGR J1935+2154 suggest that magnetars can make fast radio bursts (FRBs), but the emission site and mechanism of FRB-like bursts are still unidentified. Here, we report the emergence of a radio pulsar phase of the magnetar 5 months after FRB 20200428. Pulses were detected in 16.5 hours over 13 days using the Five-hundred-meter Aperture Spherical radio Telescope, with luminosities of about eight decades fainter than FRB 20200428. The pulses were emitted in a narrow phase window anti-aligned with the x-ray pulsation profile observed using the x-ray telescopes. The bursts, conversely, appear in random phases. This dichotomy suggests that radio pulses originate from a fixed region within the magnetosphere, but bursts occur in random locations and are possibly associated with explosive events in a dynamically evolving magnetosphere. This picture reconciles the lack of periodicity in cosmological repeating FRBs within the magnetar engine model.