Artistic Imagination of GRB 211211A Drawing by Lei Hanyu and Chen Jing
The team of Zhang Binbin, a professor at the School of Astronomy and Space Science of Nanjing University, discovered a gamma-ray burst GRB 211211A with special significance on observation, obtained evidence of the association between this long gamma-ray burst and a thousand nova through detailed data analysis, and originally proposed the special physical origin behind this event, pointing out that its predecessor star may be a neutron star-white dwarf merger system. On December 8, the relevant research results of Zhang Binbin’s team were published in Nature.
Since the birth of the universe, there is a class of celestial events that can actually release the sum of the sun’s lifetime energy in one second, and it is the most violent celestial explosion phenomenon – gamma ray bursts. A gamma-ray burst is an explosion of sudden increase and rapid attenuation of gamma-ray radiation from the depths of the universe, divided into short bursts and long bursts. The physical origin of long and short bursts has been the focus of debate among astronomers, who have long speculated that the two have very different physical origins: long bursts are the product of massive stars evolving to the end of nuclear collapse, accompanied by supernova explosions; Short bursts arise from compact binary mergers (i.e., neutron star-neutron stars or neutron star-black hole mergers) with a thermal transient source called a thousand novae.
Through long-term research, Zhang Binbin’s team found a case of gamma-ray burst GRB 211211A with special significance on observation, which further proved the diversity of the origin of gamma-ray bursts, and its uniqueness is that although it is a long burst, it is clearly related to thousands of novae. This is the first long gamma-ray burst to be found that has a compact star merger origin that erupts much longer than the typical time of a short burst, and the first time a thousand novae from a long burst have been found.
GRB 211211A’s unique observational features challenge scientists’ understanding of the star system and central engine models of the precursor to gamma-ray bursts. The team believes that the white dwarf-neutron star merger produces a fast-spinning, highly magnetized neutron star, or magnetar. The magnetar’s rotational and magnetic energy drives 55 seconds of extended radiation and thousands of seconds of X-ray platform radiation, and provides an additional injection of energy into the thousand novae. The research team proposed this scheme for the first time to explain GRB 211211A, noting that it can self-consistently and completely meet all the observational characteristics of the storm. Future low-frequency gravitational wave detectors are expected to confirm the existence of such a progenitor star system.
It is reported that the achievement is with Nanjing University as the first author unit and the first communication unit, Yang Jun, a doctoral student in the School of Astronomy and Space Science of Nanjing University, as the first author, Zhang Binbin and Professor Zhang Bing of the University of Nevada as the corresponding authors. (Source: China Science News, Wen Caifei, Yu Yuehan)
Related paper information:https://doi.org/10.1038/s41586-022-05403-8