Conversations With An Astrophysicist - Fast Radio Bursts

KnowTheCosmos ^ | 13 February 2015 | Scott Lewis

[Steely Tom]

With regard to power, one of the videos on FRBs states that the estimated energy in one pulse is 10^30 joules, which would make them basically the brightest objects in the universe. That's assuming the radiation pattern is isotropic, which certainly doesn't have to be the case. The class of objects knows as "quasars" were originally thought to be the brightest objects in the universe, but (I believe) that was later shown to be probably false; quasars are now thought to be beam phenomena that happened to be aimed directly at us.

In the video I link in this story, one of the professors talks about a theory that the FRBs result from a magnetic field phenomenon that may take place on magnetars, sort of an ultra-powerful magnetic star-quake, analog of a phenomenon that's been observed in solar storms on our own Sun.

I don't think the "deep shaft" theory is necessary to get such a powerful pulsing effect. You could also have two super-massive objects orbiting around a common center of mass; one of them functions — by means of its gravitational field — to focus the emissions of the other into a highly focused beam.

The frequency-sweep phenomenon is very interesting because it's fairly hard to produce in nature. To see it at such stupendous power levels and sweep rates is highly thought-provoking, and explains why this phenomenon is getting so much attention.

[TXnMA]

LOL!! The "deep shaft" was just a "gedanken experiment crutch" to confine and collimate a beam. I actually envision a "directed, collimated, coherent phenomenon" -- analogous to

"Cosmic Jets" -- except this one barely shows up at all at radio frequencies... And, of course, whole galaxies don't whirl around fast enough to present brief, repetitive pulses at a distance...'-)

~~~~

Like most everyone else here, I suspect that a magnetar may be a good culprit to blame for this one... '-)

[Steely Tom]

The power of those jets is astonishing. They affect space around them out to a distance of hundreds of light years, if not more.

Those are amazing pictures. The one in x-ray wavelengths is astonishing. I didn’t realize we had the technology to make such an image.

[Tucker39]

Thanks.

[Does so]

We are alone.

[pfflier]

Agree. At that distance, any entity would not travel fast enough to generate a curve. That is assuming that no entity can travel faster that the speed of light.

[ProtectOurFreedom]

And that those ETs weren’t beam-forming straight at us.

[TXnMA]

Psychic ETs: knew millions of years ago to aim at us... </SARC>

[Windflier]

I would call it both amplitude and frequency modulated.

What inference do you draw from that?

[Windflier]

We are alone.

So said the tube worm to the white crab on the geothermal vent...

[TXnMA]

I agree with Steely Tom's assessment in #39.

There are several (natural) ways to get a short pulse (amplitude modulation) from a rapidly spinning source.

Had the frequency sweep modulation been linear, then I might suspect an other-than-natural source. But -- the freq sweep is nonlinear...

[ProtectOurFreedom]

Yep. They knew exactly which pile of rocks was going to get the right primordial soup.

[TXnMA]

On the off chance that you're not familiar with it, I'd like to share the URL for the APOD (Astronomy Picture Of the Day) archives with you:

https://129.164.179.22/apod/archivepix.html

I sometimes forget to check it for a while -- and, then go an "APOD binge"... '-)

I found the photo in #42 by using its SEARCH function for "Cosmic Jets"...

[Steely Tom]

There are several (natural) ways to get a short pulse (amplitude modulation) from a rapidly spinning source.

Had the frequency sweep modulation been linear, then I might suspect an other-than-natural source. But -- the freq sweep is nonlinear...

I just had a really cool thought, worthy (IMHO) of inclusion in a science-fiction story.

What if FRBs are caused by the lighting-off of a relativistic-drive spaceship somewhere far away? Perhaps with it's "exhaust" (or antenna, or plasma beam) aimed directly at us.

Kind of the galactic equivalent of the sound of a hot rod peeling out half a mile away.

[TXnMA]

LOL! That has a bit of wacky charm that tickles my whimsy!

FTL burnout...