Artists conception of the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China. Credit: Jingchuan Yu
Fast radio bursts (FRBs) are extremely dispersed millisecond-duration radio bursts. Since the discovery of the very first FRB in 2007, a number of hundred of them had actually been found.
Most of the FRBs that have been discovered originated from outside of the Milky Way. Recent observations of an FRB originating from a Galactic magnetar (a type of neutron star precious to have an extremely strong magnetic field) indicate that some FRBs originate from magnetars. Nevertheless, the origin of the cosmological FRBs, especially those that actively repeat, remains uncertain. So far, the restrictions to the physical criteria of the environments close to FRBs are still weak.
Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), the FAST FRB Key Project Team discovered almost 2,000 radio bursts from FRB 20201124A. Their research highly suggests that FRB 2021124A is embedded in a complicated, dynamically evolving allured environment. Their results assist us comprehend how these radio bursts were produced, and how the radio burst signal propagated in the regional allured environment.
The Five-hundred-meter Aperture Spherical radio Telescope (FAST) lies in a natural anxiety in the landscape in Guizhou, China. It is the worlds largest single-dish radio telescope, with a 500 meter (1,600 foot) diameter dish and a getting area equivalent to 30 football fields.
The Five-hundred-meter Aperture Spherical radio Telescope is a radio telescope situated in a natural basin in Pingtang County, Guizhou, southwest China. It includes a repaired 500 m (1,600 feet) size meal and is the worlds biggest filled-aperture radio telescope.
The FAST FRB Key Project Team includes Kejia Lee (Peking University, NAOC), Weiwei Zhu (NAOC), Subo Dong (Peking University), Bing Zhang (University of Nevada), Heng Xu (Peking Univsersity, NAOC), Ping Chen (Peking University), Jiarui Niu (NAOC).
In a Nature paper that was just recently published, the FAST FRB group reported using FAST to keep track of FRB 20201124A for about 2 months. The high event rate makes FRB 20201124A amongst the most active known FRBs.
The group of astrophysicists discovered several phenomena never found before. One is the irregular short-time variation of the Faraday rotation step, which probes the line-of-sight magnetic field strength of individual bursts during the very first 36 days, followed by a constant value. They also experienced the quenching of the burst activity on a timescale shorter than three days. Furthermore, they detected prominent circular polarization in these bursts (as much as 75%). Lastly, they found oscillations in fractional direct and circular polarizations along with polarization angle as a function of wavelength.
All these functions supply strong proof for a complex, dynamically evolving allured environment within about one astronomical system of this FRB source. Based upon the oscillation structures in polarizations, the astrophysicists set a restraint to the magnetic field to this allured local environment, which reaches gauss level.
Observations with the Keck 10m optical telescope reveal that FRB 20201124A lives in a low-density interim area of a Milky Way-like galaxy. This environment is irregular with a young magnetar engine formed throughout a severe surge of a massive star that led to a long gamma-ray burst or superluminous supernova.
” This resembles taking a film of the environments of an FRB source,” stated Bing Zhang, “and our movie exposes a complex, dynamically evolving, magnetized environment that was never ever pictured before”. Such an environment is not straightforwardly anticipated for a separated magnetar. “Something else may be in the vicinity of the FRB engine, possibly a binary companion,” included Zhang.
” This is the largest sample of FRB information with polarization info from one single source,” stated Weiwei Zhu.
” This area is inconsistent with a young magnetar main engine formed throughout a severe explosion such as a long gamma-ray burst or a superluminous supernova, widely hypothesized progenitors of active FRB engines,” stated Subo Dong.
For more on this discovery, see Mysterious Fast Radio Bursts Defy Current Understanding.
Reference: “A quick radio burst source at a complicated allured website 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.
Fast radio bursts (FRBs) are highly dispersed millisecond-duration radio bursts. Current observations of an FRB stemming from a Galactic magnetar (a type of neutron star precious to have an extremely strong magnetic field) suggest that some FRBs come from magnetars. Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), the FAST FRB Key Project Team identified almost 2,000 radio bursts from FRB 20201124A. In a Nature paper that was just recently released, the FAST FRB team reported utilizing FAST to monitor FRB 20201124A for about 2 months. The high occasion rate makes FRB 20201124A amongst the most active recognized FRBs.
