Artist’s conception of Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China. Credit: Jingchuan Yu
Fast Radio Bursts – A Puzzling and Deepening Mystery
An worldwide group of scientists reveals an evolving, magnetized setting and stunning supply location for deep-space quick radio bursts – observations that defy present understanding.
Fast radio bursts (FRBs) are millisecond-long cosmic explosions that every produce the power equal to the solar’s annual output. Their perplexing nature continues to shock scientists greater than 15 years after the deep-space pulses of electromagnetic radio waves have been first found. Now, newly printed analysis solely deepens the thriller surrounding them.
Unexpected new observations from a collection of cosmic radio bursts by a global group of scientists problem the prevailing understanding of the bodily nature and central engine of FRBs. The researchers, which incorporates University of Nevada, Las Vegas (UNLV) astrophysicist Bing Zhang, printed their findings within the September 21 problem of the journal Nature.
The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is situated in a pure melancholy within the panorama in Guizhou, China. It is the world’s largest single-dish radio telescope, with a 500 meter (1,600 foot) diameter dish and a receiving space equal to 30 soccer fields. It is anticipated that FAST will preserve its world-class standing for the subsequent 20 to 30 years. With its progressive design, FAST has damaged the 100-meter engineering restrict for telescope building and created a brand new mode to construct giant radio telescopes.
The cosmic FRB observations have been made in late spring 2021 utilizing the huge Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China. The group detected 1,863 bursts in 82 hours over 54 days from an lively quick radio burst supply known as FRB 20201124A. The scientists have been led by Heng Xu, Kejia Lee, Subo Dong from Peking University, and Weiwei Zhu from the National Astronomical Observatories of China, together with Zhang.
“This is the largest sample of FRB data with polarization information from one single source,” stated Lee.
Recent observations of a quick radio burst from our Milky Way galaxy indicate that it originated from a magnetar, which is a dense, city-sized neutron star with an incredibly powerful magnetic field. On the other hand, the origin of very distant cosmological fast radio bursts remains unknown. And these latest observations leave scientists questioning what they thought they knew about them.
“These observations brought us back to the drawing board,” said Zhang, who also serves as founding director of UNLV’s Nevada Center for Astrophysics. “It is clear that FRBs are more mysterious than what we have imagined. More multi-wavelength observational campaigns are needed to further unveil the nature of these objects.”
The Five-hundred-meter Aperture Spherical radio Telescope (FAST), nicknamed Tianyan (“Eye of the Sky/Heaven”) is a radio telescope located in the Dawodang depression, a natural basin in Pingtang County, Guizhou, southwest China. It consists of a fixed 500-meter diameter dish constructed in a natural depression in the landscape. It is the world’s largest filled-aperture radio telescope, and the second-largest single-dish aperture after the sparsely-filled RATAN-600 in Russia.
What makes the latest observations surprising to scientists is the irregular, short-time variations of the so-called “Faraday rotation measure,” essentially the strength of the magnetic field and density of particles in the vicinity of the FRB source. The variations went up and down during the first 36 days of observation and suddenly stopped during the last 18 days before the source quenched.
“I equate it to filming a movie of the surroundings of an FRB source, and our film revealed a complex, dynamically evolving, magnetized environment that was never imagined before,” said Zhang. “Such an environment is not straightforwardly expected for an isolated magnetar. Something else might be in the vicinity of the FRB engine, possibly a binary companion,” added Zhang.
To observe the host galaxy of the FRB, the team of astronomers also made use of the 10-m Keck telescopes located at Mauna Kea in Hawaii. Zhang says that young magnetars are believed to reside in active star-forming regions of a star-forming galaxy, but the optical image of the host galaxy shows that – unexpectedly – it’s a metal-rich barred spiral galaxy like our Milky Way. The FRB location is in a region where there is no significant star-forming activity.
“This location is inconsistent with a young magnetar central engine formed during an extreme explosion such as a long gamma-ray burst or a superluminous supernova, widely speculated progenitors of active FRB engines,” said Dong.
Reference: “A fast radio burst source at a complex magnetized site in a barred galaxy” by H. Xu, J. R. Niu, P. Chen, K. J. Lee, W. W. Zhu, S. Dong, B. Zhang, J. C. Jiang, B. J. Wang, J. W. Xu, C. F. Zhang, H. Fu, A. V. Filippenko, E. W. Peng, D. J. Zhou, Y. K. Zhang, P. Wang, Y. Feng, Y. Li, T. G. Brink, D. Z. Li, W. Lu, Y. P. Yang, R. N. Caballero, C. Cai, M. Z. Chen, Z. G. Dai, S. G. Djorgovski, A. Esamdin, H. Q. Gan, P. Guhathakurta, J. L. Han, L. F. Hao, Y. X. Huang, P. Jiang, C. K. Li, D. Li, H. Li, X. Q. Li, Z. X. Li, Z. Y. Liu, R. Luo, Y. P. Men, C. H. Niu, W. X. Peng, L. Qian, L. M. Song, D. Stern, A. Stockton, J. H. Sun, F. Y. Wang, M. Wang, N. Wang, W. Y. Wang, X. F. Wu, S. Xiao, S. L. Xiong, Y. H. Xu, R. X. Xu, J. Yang, X. Yang, R. Yao, Q. B. Yi, Y. L. Yue, D. J. Yu, W. F. Yu, J. P. Yuan, B. B. Zhang, S. B. Zhang, S. N. Zhang, Y. Zhao, W. K. Zheng, Y. Zhu and J. H. Zou, 21 September 2022, Nature.
DOI: 10.1038/s41586-022-05071-8
The study appeared September 21 in the journal Nature and includes 74 co-authors from 30 institutions. In addition to UNLV, Peking University, and the National Astronomical Observatories of China, collaborating institutions also include Purple Mountain Observatory, Yunnan University, UC Berkeley, Caltech, Princeton University, University of Hawaii, and other institutions from China, the USA, Australia, Germany, and Israel.
