Gemini: Astronomers Capture and Tag a Fleeting Radio Burst

[bystander]

Cosmic Cat and Mouse: Astronomers Capture and Tag a Fleeting Radio Burst
Gemini Observatory | 2019 Jun 27

Gemini Observatory provides critical observations that confirm the distance to a mysterious, very short-lived, radio outburst from a galaxy billions of light years away.

ASKAP pinpoints location of one-off radio burst 4 billion
light years away ~ Credit: CSIRO/Sam Moorfield

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An Australian-led team of astronomers using the Gemini South telescope in Chile have successfully confirmed the distance to a galaxy hosting an intense radio burst that flashed only once and lasted but a thousandth of a second. The team made the initial discovery of the fast radio burst (FRB) using the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope.

The critical Gemini observations were key to verifying that the burst left its host galaxy some 4 billion years ago..

Since the first FRB discovery in 2007, these mysterious objects have played a game of cosmic cat-and-mouse with astronomers — with astronomers as the sharp-eyed cats! Fleeting radio outbursts, lasting about a millisecond (one-thousandth of one second), are difficult to detect, and even more difficult to locate precisely. In this case, the FRB, known as FRB 180924, was a single burst, unlike others that can flash multiple times over an extended period. ...

The momentary pulse was first spotted in September 2018 during a dedicated search for FRBs using ASKAP — a 36-antenna array of radio telescopes working together as a single instrument in Western Australia — which also pinpointed the signal’s location in the sky.

The researchers used the miniscule differences in the amount of time it takes for the light to reach different antennas in the array to zoom in on the host galaxy’s location. ...

Once pinpointed, the team enlisted the Gemini South telescope, along with the W.M. Keck Observatory and European Southern Observatory’s Very Large Telescope (VLT) to determine the FRB’s distance and other characteristics by carefully observing the galaxy that hosted the outburst. ...

Astronomers Make History in a Split Second
CSIRO | via EurekAlert | 2019 Jun 27

Astronomers Make History in a Split Second with Localization of Fast Radio Burst
University of California, Santa Cruz | 2019 Jun 27

Optical Telescopes Image Origin of FRB Detected by ASKAP
European Astronomical Society | 2019 Jun 27

A Single Fast Radio Burst Localized to a Massive Galaxy at Cosmological Distance ~ K.W. Bannister et al

• Science (online 27 Jun 2019) DOI: 10.1126/science.aaw5903
• arXiv.org > astro-ph > arXiv:1906.11476 > 27 Jun 2019

[bystander]

Fast Radio Burst Pinpointed to Distant Galaxy
California Institute of Technology | W.M. Keck Observatory | 2019 Jul 02

Owens Valley Radio Observatory is providing new clues in an ongoing cosmic mystery.

The Deep Synoptic Array ten-antenna prototype (DSA-10) searches for fast radio bursts within a sky-area the size of 150 full moons (left). Within this area, the DSA-10 can locate these bursts with immense resolving power, isolating them to regions containing just one galaxy (middle). This feat was achieved for the fast radio burst called FRB 190523, detected by DSA-10 on May 23, 2019. The right panel shows the time profile of the burst above its radio spectrum. (Credit: Caltech/OVRO/V. Ravi)

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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.

In a rare feat, researchers at Caltech’s Owens Valley Radio Observatory (OVRO) have now caught a new burst, called FRB 190523, and, together with the W. M. Keck Observatory in Hawaii, have pinpointed its origins to a galaxy 7.9 billion light-years away. Identifying the galaxies from which these radio bursts erupt is a critical step toward solving the mystery of what triggers them. ...

Before this new discovery, only one other burst, called FRB 121102, had been localized to a host galaxy. FRB 121102 was reported in 2014 and then later, in 2017, was pinpointed to a galaxy lying 3 billion light-years away. Recently, a second localized FRB was announced on June 27, 2019. Called FRB 180924, this burst was discovered by a team using the Australian Square Kilometer Array Pathfinder and traced to a galaxy about 4 billion light-years away.

FRB 121102 was easiest to find because it continues to burst every few weeks. Most FRBs, however -- including the Australian and OVRO finds -- just go off once, making the job of finding their host galaxies harder. ...

The new observations show that the host galaxy for FRB 190523 is similar to our Milky Way. This is a surprise because the previously located FRB 121102 originates from a dwarf galaxy that is forming stars more than a hundred times faster than the Milky Way. ...

The discovery also suggests that a leading theory for what causes FRBs -- the eruption of plasma from young, highly magnetic neutron stars, or magnetars -- may need to be rethought. ...

A Fast Radio Burst Localized to a Massive Galaxy ~ V. Ravi et al

• Nature (online 02 Jul 2019) DOI: 10.1038/s41586-019-1389-7
• arXiv.org > astro-ph > arXiv:1907.01542 > 02 Jul 2019