Fast Radio Bursts – a new class of astronomical phenomena | Hacker News Reader

Fast Radio Bursts – a new class of astronomical phenomena

swinburne.edu.au

57 pointsGnwbZHiU8 comments

Fascinating from a scientific perspective, but this line piqued my interest the most:

  The detection system used can process 20 Gigabytes of data per second.

Now I know that's not unheard of, but it certainly would be interesting from a technical perspective to know how it processes such volumes of data. (And also makes me think about a certain other party in current events that is processing vast volumes of data every second as well.)

i would guess they're talking about FPGA correlators for the radio signal.

how are they estimating distance? the article says "the furthest one that we detected was 11 billion light years away" which is an odd statement to make about a signal from an unknown process, unless, say it was monchromatic (and of known rest-frame frequency, which likely implies some physical process, and redshifted).

This is from the link below, and I think it sums it up:

>> The beautiful sweep and pulse shape of the radiation obeys the theoretically-predicted relation for a burst of radio waves that has propagated across the universe.

My understanding is that it matches what a sharp burst should look like after passing through 11 billion light-years' worth of electrons.

http://theconversation.com/fast-radio-bursts-new-intergalact...

omega tau did an interesting podcast on radio telescopes which included a discussion about the specialized hardware radio telescopes use to process the signal data. I think it was on: http://omegataupodcast.net/2009/08/16-radio-astronomy-and-th...

> The researchers are now looking to determine the origin of the bursts. A precise position would enable them to "count" the number of electrons in the Universe, which would be a tremendous breakthrough for cosmology.

can anyone elaborate on this? an exact count?

wild guess - electrons on the path mess with the signal in some way, with an effect proportional to their total number along the path (if these are meant to be very short pulses, maybe it smears them out in time, for example, or perhaps it changes their polarization). so if you know the distance you can get the average density along that path. then you assume that the universe is uniform (but evolving) and do the math (whether you call that exact or not...)

oh, and presumably electron density is useful because it gives you (approx) proton density (assuming net charge of universe is zero!) which gives you ionized hydrogen density, which sounds like it would be a useful thing to know (you can see un-ionized hydrogen via absorption spectra, so if you add them together you get total hydrogen density, which is related to total normal matter density...)

it's not clear to me how you do this without knowing how far away the sources are (see my earlier post).

Is there any chance these could be alien signals or byproducts of alien technology? (It sounds pretty outlandish to ask until you realize hundreds of professionals actually spend their careers attempting to answer such questions [1])

[1] http://www.seti.org/

Extremely unlikely given the vast distance.

Swinburne Pro Vice-Chancellor (Research) Professor Matthew Bailes thinks the most likely source of the bursts are cataclysmic explosions in the Universe's most magnetic neutron stars, otherwise known as magnetars.

"Magnetars can give off more energy in a millisecond than our Sun does in 300,000 years and are a leading candidate for the bursts," he said.

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