green-bank-telescope
September 1, 2017

Astronomers detect 15 unusual radio signals from space

The same object that in 2015 became the first ever to be observed giving off repeating fast radio bursts has now emitted more than a dozen additional signals, members of a program designed to hunt for extraterrestrial life in other parts of the universe announced earlier this week.

The object, identified as FRB 121102, is located in a dwarf galaxy some three billion light years from Earth and was first detected giving off a fast radio burst back in November 2012, according to New Scientist. Three years later, it was observed giving off a second, CBS News added.

Now, scientists affiliated with Breakthrough Listen, an international astronomical initiative first launched by philanthropist Yuri Milner and cosmologist Stephen Hawking three years ago, have reported the detection of an additional 15 bursts of radio emissions emanating from the object.

Furthermore, New Scientist explained, the signals were detected at a higher frequency than ever before. Using an instrument on the Green Bank Telescope in West Virginia, the researchers were able to collect more than 400 GB worth of data across the entire 4 to 8 GHz frequency band over a five-your observational period. The significance of their discovery is unclear at this time.

“The possible implications are two folds,” lead investigator Dr. Vishal Gajjar from UC Berkeley told CNET via email. “This detection at such a high frequency helps us scrutinize many (of FRB 121102's) origin models. The frequency structure we see across our total band of 4 to 8 GHz also allows us to understand the intervening medium between us and the source.”

Findings could make it easier to find additional FRBs

Fast radio bursts are high-energy astrophysical phenomena that manifest themselves as a short-lived (usually only a few millisecond long) radio pulse. While the precise origins are unknown, some experts believe that they originate from black holes or intelligent extraterrestrial life, New Scientist explained.

The new signals, which were detected on August 26, confirm that the source is in a newly active state, the Breakthrough Listen scientists reported in the Astronomer's Telegram. Furthermore, the high resolution of the data collected will enable them to complete the most precise measurements of FRB properties to date – potentially making it easier to find additional FRBs elsewhere.

“Previously we thought there wasn’t much emission at high or low frequencies, but now it looks like there is. It’s twice as high as the typical frequency,” Harvard University scientist Avi Loeb told New Scientist. The additional frequency range could make it easier to detect repeating FRBs, he said, but it also makes these already unusual phenomenon just a little bit stranger.

As Loeb’s Harvard colleague, Peter Williams, added, “It’s very funky how the individual bursts can pop up anywhere in this wide range of frequencies, even though each individual burst has a relatively narrow frequency coverage. I have yet to see anyone offer up a good explanation for how that might happen.”

In addition to being the only confirmed source to have been detected giving off multiple bursts, FRB 121102 is the only emitted to have had its location positively confirmed in space, according to CBS News. The dwarf galaxy in which it is located is reportedly much smaller than the Milky Way, they said, and contains approximately half as many stars.

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Image credit: Jarek Tuszyński