by Theodore R Frimet
feast or famine
Exciting news awaits the general public. Fast Radio Bursts. FRB’s become the new darling of what’s up the in sky tonight! Starting with the MSN title of “Scientists detect an unexplainable radio signal from outer space that repeats every 16 days”, we are led into a cosmological brief that in and of itself, is fairly harmless. However the editorial content, is more akin to citing some other article, and repeating the news.
Sad, for me to say, considering my political leanings, yet here it is, “fake news”. Oh, woe is to me! Well, perhaps not fake, yet not original content. Chasing the story down this fabled rabbit hole, fortunately, yields only one other article cited. So, perhaps not so fake, as it was probably the authors intent to reach an audience, at MSN (1), that would otherwise not be in touch with Astronomy? I must genuflect, and pardon my purvey of the previous notion. The news, here, is not fake. It is a complex link; copying, pasting, and offering correct citation to the original author, Doyle Rice of USA Today.
MSN goes on to write, “This article originally appeared on USA TODAY (2): Scientists detect an unexplainable radio signal from outer space that repeats every 16 days”. True that! If we were to obtain our news source from Google News, we need only click, “view full coverage”, and be aghast with the same news feed, time and time again, being repeated to every Tom, Dick, and Jane. I suppose that is sauce for the goose, as the article could very well repeat, as many times as the oft cited FRB. Let’s move onto USA today, so we don’t miss any tidbits, shall we?
The article starts off with, “For the first time, scientists have detected a radio signal from outer space that repeats at regular intervals.” Let’s give them some slack, here. As most of you are respectful of me, and forgive my gaffs all the time. Observable radio signals that are cyclical are not new. I get it, though. The authors intent is to highlight FRB’s. However, is this a one off?
The Canadian radio telescope, CHIME (3), has mapped out a few FRBs. One of which was repeating. Although not at a regular interval. (https://arxiv.org/abs/1908.03507) Eight FRBs were detected. These 8 were indistinguishable from the first 12 CHIME/FRB sources non-repeating sources detected. So what is it that the paper boy has hoisted on top of our roof, today?
28 bursts followed. All came within a four day window. The periodicity is 16.35 +/- 0.18 day for the lonely FRB 180916.J0158+65. Sifting thru the journal report (4), a few methods are delivered for perusal. Notably, there is still some science to be performed, all in an effort to understand the relationship between burst activity and emission frequency. The report justly states burst rate activity is not consistent with the active phase, without definition.
Changing the observable interval, in days, the activity epoch varies. This is demonstrated for +/- 0.8 days (12 out of 28 detections with 95% confidence), and +/- 2.6 days intervals based upon 19 of the 28 detections. I could be wrong here, however, they are referring to mean peak burst delivery, within their stated 4 day window. So, where is the cliff hanger for the 16.35 days interval?
The periodicity is clearly there. FRB 180916.J0158+65 is a significant accomplishment.
It is duly noted (CHIME/FRB collaboration et al) in a periodogram of FRB 180916.J0158+65 and control samples. In their figure 1, the first 3 subharmonics of the 16.35 day periodicity are graphically depicted below. Look for the arrows.
1) Rice, D. (2020, February 13) Scientists detect an unexplainable radio signal from outer space that repeats every 16 days. Retrieved from https://bit.ly/37udue6 last accessed Sunday, February 16, 2020 10:02 AM EST.
Non bit.ly URL: https://www.msn.com/en-us/news/technology/scientists-detect-an-unexplainable-%20radio-signal-from-outer-space-that-repeats-every-16-days/ar-BBZUUS5?li=BBnbf%20cL&ocid=iehp
(2) Rice, D. (2020, February 12 – USA Today header notes: Published 6:00 a.m. ET Feb. 12, 2020 / Updated 12:26 PM ET Feb 12, 2020.) Scientists detect an unexplainable radio signal from outer space that repeats every 16 days. Retrieved from https://bit.ly/2vAHLL2 last accessed Sunday February 16, 2020 10:07 AM
Non bit.ly URL: https://www.usatoday.com/story/news/nation/2020/02/12/fast-radio-burst-signal-outer-space-repeats-every-16-days/4726301002/
(3) CHIME – Learn more about the Canadian Hydrogen Intensity Mapping Experiment (CHIME), here: https://chime-experiment.ca
(4) The CHIME/FRB Collaboration, “Periodic activity from a fast radio burst source” https://arxiv.org/pdf/2001.10275v3.pdf last accessed Sunday, February 16, 2020, 10:26 AM EST. The article was archived in ARXIV on 3 February 2020.
Watch this YouTube presentation on CHIME. Become acquainted with its ability to look at large swatches of the sky. CHIME is not a conventionally shaped radio antennae. It is composed of several half-pipes, oriented North-South. As the Earth rotates, CHIME listens in on the Northern Sky, each night. There are presumably thousands of FRB’s out there. With CHIME, the science continues with eyes wide open, to the larger, and grander scale of the known universe.
It is noteworthy that the YouTube presentation reminds us that radio wave pulses that are fractions of a second, and before they become Earth based detections they become stretched in time. This makes detection even more challenging.
Find the video here (last accessed Sunday, February 16, 2020, 10:22 AM):
Or visit the CHIME gallery, here: