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New Options for Locating Fast Radio Bursts

Our catalog of distant, highly energetic events continues to grow. On the Fast Radio Burst (FRB) front, we have the welcome news that the Molonglo radio telescope some 40 kilometers from Canberra, Australia has undergone extensive re-engineering, a project that is paying off with the detection of three new FRBs. The telescope’s collecting area of 18,000 square meters and an eight square degree field of view make it ideal for such work.


Image: Artist’s impression shows three bright red flashes depicting Fast Radio Bursts far beyond the Milky Way, appearing in the constellations Puppis and Hydra. Credit: James Josephides/Mike Dalley.

You’ll recall that Fast Radio Bursts are millisecond long, intense pulses that can appear out of nowhere with a luminosity a billion times greater than anything we have observed in the Milky Way. The phenomenon was noted for the first time a decade ago at the Parkes radio telescope in New South Wales. The sources remain enigmatic, but Manisha Caleb, a PhD candidate at Australian National University, has been developing software to examine the 1000 TB of data that is being produced daily at the Molonglo site. The new FRBs are the result.

“Conventional single dish radio telescopes have difficulty establishing that transmissions originate beyond the Earth’s atmosphere,” says Swinburne University’s Dr Chris Flynn.

But Molonglo (the Molonglo Observatory Synthesis Telescope, to give its full name, usually shortened to MOST) is a parabolic, cylindrical antenna consisting of 88 bays, each of these made up of four identical modules, to produce 352 independent antennae. The upgrade to the Molonglo instrument is known as UTMOST. The researchers used the array in a 180-day survey of the Southern sky, carrying out up to 100 hours of follow-up for each FRB, though no repeating bursts were seen. A repeating burst at UTMOST, or an FRB simultaneously detected at Parkes and UTMOST, would allow a localization of a few arcseconds.

From the paper (note that “ is the symbol for arcseconds):

In this paper we present the first interferometric detections of FRBs, found during 180 days on sky at UTMOST. The events are beyond the ≈ 104 km near-field limit of the telescope, ruling out local (terrestrial) sources of interference as a possible origin. We demonstrate with pulsars that a repeating FRB seen at UTMOST has the potential to be localised to ≈ 15” diameter error circle, an exciting prospect for identifying the host.


Image: View of the MOST at the end of the East arm looking West. Two arms, each 800 meters long, together have a collecting area of circa 18,000 square meters. MOST is the largest radio telescope in the Southern hemisphere. Credit: Swinburne University/UTMOST.

The recent discoveries point to a new ability to locate FRBs in the sky, allowing us to link them to specific galaxies, a feat that has been accomplished only once so far (see Pinpointing a Fast Radio Burst). The paper is Caleb et al., “The first interferometric detections of Fast Radio Bursts,” accepted at Monthly Notices of the Royal Astronomical Society (preprint). For more, see this UTMOST news release.


Comments on this entry are closed.

  • Harry R Ray April 4, 2017, 13:23

    The only surprising thing about this initial run is that three detected 843 MHz FRB’s are WAY TOO MANY for just 180 days of data! The most likely reason for this is that this is JUST a STATISTICAL ABERRATION(like the DM multiples of 187.5 were)and will even out as more data is analyzed. HOWEVER, as I stated in a comment in the FRB post prior to this one, if this is NOT the case, non-natural signals OR a NON-EUCLIDIAN UNIVERSE may have to be invoked to explain it. STAY TUNED!

    • Ron S April 4, 2017, 21:59

      The universe is non-Euclidean, so I don’t understand your point.

      • Harry R Ray April 5, 2017, 9:16

        I am merely re-iterating what the authors stated in the last sentence of their abstract. Obviously, with the curvature of space-time, two parallel lines CAN intersect, but, as far as I am aware, ONLY AT A SINGULARITY. I think that they ar4e referring to NORMAL space-time.

        • Ron S April 5, 2017, 21:12

          Ah, I now see. This is regarding whether the universe is flat — E^3.

          Regardless of whether this is true I do not believe the referenced paper has anything of consequence to say about it. Look in the paper for the error bars: they are huge. Not only that they have poor information on the FRB spectrum since their bandwidth is small and centered on 843 MHz, and they have not as yet been able to correlate with Parkes (1.4 GHz) on any FRB. Even then, without the data favoring any particular FRB source mechanism it is merely speculation to jump to interpretations of the data.

          For them to talk of an E^3 test is, in my worthless opinion, meaningless at this time.

          • Michael April 6, 2017, 8:27

            In my opinion the universe appears locally to be flat because of the mass on its surface.

            If you use an analogy of a beach ball you will see it as round if you are near its surface, but when you have mass on it Space-Time will be deformed locally to look flat, this is what we see in my opinion. I am in favour of a cyclic Universe where there is a ‘Big bang’ and then a ‘Big crunch’ when then all the matter/energy goes to the other side of this ‘spheric space’ and collapses to a singularity…and somehow starts over again.

  • Douglas Dwyer April 4, 2017, 16:35

    FRBs are distinctive because of their modulation most probably dispersion which ties up with pulsar dispersion which is easier to measure as it is not not a single pulse, FRBs convey the same dispersion but must originate from a different mechanism.
    If the dispersion is due to billions of light years travel then it is valid to infer the original pre-dispersion spectrum as an output that would be generated by a high “Q|” energy storing resonant oscillator of cosmic proportions.

  • DJ Kaplan April 4, 2017, 16:36
    • Ron S April 4, 2017, 22:02

      If I read that first paper correctly that is the design frequency of the MOST telescope at Monglolo.

      • DJ Kaplan April 5, 2017, 12:18

        So it shouldn’t seem “surprising” (as HARRY says) that three signals in a row all exhibit the same frequency.

        • Michael April 6, 2017, 5:18

          Could some be bent by lensing events to occur at different times and appear from different directions but are the same event. Where there are powerful explosions there are most likely powerful gravitational forces at play.

  • Douglas Dwyer April 4, 2017, 16:52

    If FRBs bear the dispersion of a passage through millions or billions of light years then it will be valid to reconstruct the original high Q spectrum by removing the dispersion. The resultant signal is what would be created by an energy storing resonant oscillator of cosmic proportions. One application for FRBs would be as a naturally occurring chirp radar signal source.

  • Robert G April 4, 2017, 18:29

    A sphere has 41253 square radians. The Molonglo site is observing 8 square radians. Manisha has detected 3 events in 180 days of data, or one event in 60 days. If the sources are all beyond the milky way they should be isotropic, so we should expect to find 41253/8=5156 times more of them: 5156 in 60 days, or 5156/60~=86 per day over the whole sky. This is the lower bound, given both the antennae and her code are 100% effective at spotting them.

    • Ron S April 4, 2017, 22:04

      A sphere has 41K square degrees, not radians. One radian is about 57 degrees.

    • Robert G April 5, 2017, 6:22

      Square degrees that should be.

  • Robert G April 4, 2017, 18:44

    The abstract from the paper quotes a figure of 78 per day, at 95% confidence, going off more accurate figures for the array. Three or four per hour.

  • David Herne April 5, 2017, 1:37

    The Murchison Widefield Array (MWA) low-frequency array (80 – 300 MHz) is being used to pursue both FRBs (https://arxiv.org/abs/1511.02985 https://arxiv.org/abs/1602.07544) and slow radio transients (https://arxiv.org/abs/1701.03557). This instrument is a precursor to the SKA low-frequency array that will be co-located.

    • DJ Kaplan April 6, 2017, 12:27

      It’s fun to note that Murchison is also the source of “that” meteorite.

  • Robert Feyerharm April 5, 2017, 21:36

    I’m curious if the Wow! signal detected in 1977 by Jerry Ehman on Ohio State University’s Big Ear radio telescope could have been a fast radio burst?

    • Harry R Ray April 6, 2017, 9:18

      No. The “WOW” signal lasted for over a minute. FRB’s last for ONLY microseconds. That is WHY they are CALLED Fast Radio Bursts!

  • Douglas Dwyer April 6, 2017, 13:15

    Published results indicate that there are many FRBs. We dont see them because detection requires a large radio telescope dish pointed at the source and a cooled receiver.
    FRB measurements are very rare but a vanishingly few were sufficiently powerful to be received without dish or cooling. One conclusion could be that a cooled receiver without a high gain antenna might pick up more of the bigger signals.
    The signal software could discriminate in favour of (be matched) to the dispersion typical of past FRBs.
    We may speculate that the magnitude of signals depends on the distance of the source.

  • ljk May 18, 2017, 9:13

    Latest fast radio burst adds to mystery of their source

    May 12, 2017

    by Bob Yirka

    (Phys.org)—An international team of space researchers has reported on the detection of a new fast radio burst (FRB) and their efforts to trace its source. They have written a paper describing the detection and search for evidence, and have uploaded it to the arXiv preprint server.

    FRBs are a relatively new development for space scientists—they are extremely short blasts of strong radio waves that come from space, but scientists have not been able to explain what makes them. In this new detection, the FRB, now named FRB 150215, was first detected by researchers working with the Parkes Telescope in New South Wales, Australia.

    What made the detection of FRB 150215 unique was that several teams were prepared to train their telescopes on the FRB origin point shortly after it was detected. Unfortunately, none of them were able to detect anything that might identify its cause, or even exactly where it occurred. exactly.

    Additionally, after analyzing data from the follow-up telescopes, the researchers found that the FRB had taken an interesting path through the Milky Way to make its way to us—a hole of sorts that, prior to the detection of the FRB, was unknown. Thus, despite learning nothing new about the source of FRBs in general, the team has learned something new about our galaxy.

    Full article here:


    To quote:

    The detection of FRB 150215 marks the detection of 22 FRBs to date, none of which have identifiable sources, making them one of the great mysteries of space science. Common sense suggests that finding a source should be relatively easy—it would take something pretty big to create such strong pulses of radio waves.

    The mysterious nature of FRBs has led to a host of theories regarding their nature, from supernova to intelligent alien communications. Others suggest the research into finding the source of FRBs has been unsuccessful because space scientists are looking at the problem backwards—FRBs, they note, could arise long after the precipitating event. That means it might make more sense to look for noticeable events in the night sky, like supernovas, and then monitor for FRBs sometime later.

    In any event, study of FRBs is likely to increase as the mystery deepens and new telescope technology emerges—some have even suggested that it is possible that FRBs are much more common than has been shown, and that once they are observed more regularly, researchers can focus on looking at patterns.

  • Michael Fidler July 29, 2017, 10:59

    Manasvi Lingam1, 2 and Abraham Loeb2
    1Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
    2Harvard-Smithsonian Center for Astrophysics, The Institute for Theory and Computation, 60 Garden Street, Cambridge, MA 02138, USA
    We examine the possibility that Fast Radio Bursts (FRBs) originate from the activity of extragalactic civilizations.
    Our analysis shows that beams used for powering large light sails could yield parameters that are consistent with FRBs.
    The characteristic diameter of the beam emitter is estimated through a combination of energetic and engineering
    constraints, and both approaches intriguingly yield a similar result which is on the scale of a large rocky planet.
    Moreover, the optimal frequency for powering the light sail is shown to be similar to the detected FRB frequencies.
    These ‘coincidences’ lend some credence to the possibility that FRBs might be artificial in origin. Other relevant
    quantities, such as the characteristic mass of the light sail, and the angular velocity of the beam, are also derived. By
    using the FRB occurrence rate, we infer upper bounds on the rate of FRBs from extragalactic civilizations in a typical
    galaxy. The possibility of detecting fainter signals is briefly discussed, and the wait time for an exceptionally bright
    FRB event in the Milky Way is estimated.


  • ljk August 2, 2017, 13:05
  • ljk August 30, 2017, 19:08
  • ljk August 31, 2017, 9:17