Fast radio bursts (FRBs) are among the most enigmatic and powerful events in the cosmos. Around 80 of these events–intensely bright millisecond-long bursts of radio waves coming from beyond our galaxy–have been witnessed so far, but their causes remain unknown. “We still have no new clue on whether the origin is artificial or natural,” said Harvard astronomer Avi Loeb about fast radio bursts (FRBs), one of the great astrophysical mysteries. In a rare feat, Caltech researchers have caught a new burst, called FRB 190523, pinpointing its origins to a galaxy 7.9 billion light-years away.
Wednesday, February 12, 2020
SPACE CADETS / E.T. WE HEAR YOU, BUT WHAT ARE YOU TRANSMITTING?
FRBs are bright, millisecond-duration radio transients originating from extragalactic distances. Their origin is unknown. Some FRB sources emit repeat bursts, ruling out cataclysmic origins for those events. Despite searches for periodicity in repeat burst arrival times on time scales from milliseconds to many days, these bursts have hitherto been observed to appear sporadically, and though clustered, without a regular pattern. Here we report the detection of a 16.35±0.18 day periodicity from a repeating FRB 180916.J0158+65 detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project (CHIME/FRB).
In 28 bursts recorded from 16th September 2018 through 30th October 2019, we find that bursts arrive in a 4.0-day phase window, with some cycles showing no bursts, and some showing multiple bursts, within CHIME's limited daily exposure. CHIME results suggest a mechanism for periodic modulation either of the burst emission itself, or through external amplification or absorption, and disfavour models invoking purely sporadic processes.
More on FRBs: Space.com video: Click here.
NEW CLUES. Clickhere: