2021-12-10 11:00  P5A-1

Multiwavelength Studies of Transient Radio Signal from Neutron Stars

Chin-Ping Hu

Neutron stars are one of the most extreme objects in the Universe. They are engines that power many short, sporadic, and energetic events in all electromagnetic wavebands. The Crab pulsar occasionally emits giant radio pulses (GRPs) that are sudden radio bursts that are several orders of magnitude brighter than regular pulses and with microsecond time scales. GRPs are one of the most promising candidates of mysterious fast radio bursts (FRBs). For a long while, GRPs have been observed only in the radio band, but an excess of visible light was found in 2003. We have conducted simultaneous observations of the Crab pulsar with a multi-wavelength campaign and found a ~4% X-ray enhancement coinciding with GRP occurrence. This indicates total energy is much higher than previously expected. This result, together with the recently discovered galactic FRB in a magnetar SGR 1935+2154, does not favor the current GRP-FRB model. Our recent studies of bursts of a few magnetars suggest that X-ray short bursts may have different origins. Future observations and systematic studies of radio and X-ray bursts would help understand the activities of neutron stars.