Most Extreme Gamma-ray Blast Ever

BoJangles · Feb 23, 2009

Most Extreme Gamma-ray Blast Ever, Seen By Fermi Gamma-ray Space Telescope With the greatest total energy, the fastest motions, and the highest-energy initial emissions ever before seen, a gamma-ray burst recently observed by the Fermi Gamma-ray Space Telescope is one for the record booksThe burst is not only spectacular but also enigmatic: a curious time delay separates its highest-energy emissions from its lowest. Such a time lag has been seen clearly in only one earlier burst, and researchers have several explanations for why it may exist.  http://www.sciencedaily.com/releases/2009/02/090219141458.htm---I think the time delay is interesting, and its seen with supernovae too I believe, maybe the speed of light isn’t constant across the spectrum?Additionally what god awful things could be happening at this immature age in the universe to be creating such calamity?---It must be like black hole mergers or something, even then why wouldnt we be seeing them at all ages of the universe, as galaxies are merging all the time.  <div class="Discussion_UserSignature"> -------------- Let me start out with the standard disclaimer ... I am an idiot, I know almost nothing, I haven’t taken calculus, I don’t work for NASA, and I am one-quarter Bulgarian sheep dog. With that out of the way, I have several stupid questions... *** A few months blogging can save a few hours in research *** </div>

michaelmozina · Feb 24, 2009

Replying to: <DIV CLASS='Discussion_PostQuote'>Most Extreme Gamma-ray Blast Ever, Seen By Fermi Gamma-ray Space Telescope With the greatest total energy, the fastest motions, and the highest-energy initial emissions ever before seen, a gamma-ray burst recently observed by the Fermi Gamma-ray Space Telescope is one for the record booksThe burst is not only spectacular but also enigmatic: a curious time delay separates its highest-energy emissions from its lowest. Such a time lag has been seen clearly in only one earlier burst, and researchers have several explanations for why it may exist.  http://www.sciencedaily.com/releases/2009/02/090219141458.htm---I think the time delay is interesting, and its seen with supernovae too I believe, maybe the speed of light isn’t constant across the spectrum?Additionally what god awful things could be happening at this immature age in the universe to be creating such calamity?---It must be like black hole mergers or something, even then why wouldnt we be seeing them at all ages of the universe, as galaxies are merging all the time.  Posted by BoJangles</DIV>From the article. Replying to: <DIV CLASS='Discussion_PostQuote'>With the distance in hand, FGST team members showed that the blast exceeded the power of nearly 9,000 ordinary supernovae and that the gas bullets emitting the initial gamma rays must have moved at no less than 99.9999 percent the speed of light. This burst's tremendous power and speed make it the most extreme recorded to date.</DIV>Holy cow!    I guess even at an early age the universe evidnetly had some very large structures to work with:  http://www.world-science.net/othernews/090106_blackholes.htm <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

chris1996 · Nov 5, 2009

It was probably from a very large magnitar.
They are said to emit large bursts of radiation on occasion with a thousand times more power
then a pulsar. :!:

SpaceTas · Nov 7, 2009

Magnetars do emit very strong bursts of gamma-rays, in 2 categories "normal bursts" and super-flares. But the energy from this gamma-ray burst is way more it's enough to rip the neutron star appart. Also spectrum of the gamma-ray bursts from magnetars are different from these gamma-ray bursts. The spectrum peaks at lower energies.

The best guess for the origin of these distant gamma-ray bursts is the collapse of a super massive star (100 solar mass). Such massive stars don't form anymore; because elements "heavier" than Hydrogen and Helium absorb more high energy light (UV, X-ryas etc) making super-massive stars unstable. The pressure from the light they produce stop them from forming.

R1 · Nov 9, 2009

Re:

BoJangles":3dbkojwc said:
?Additionally what god awful things could be happening at this immature age in the universe to be creating such calamity?---It must be like black hole mergers or something, even then why wouldnt we be seeing them at all ages of the universe, as galaxies are merging all the time.

Things like this that we see so far away actually happened prior to the expansion acceleration, correct?
I mean the other thread, iirc, metions that the expansion acceleration has only started in the
last 5 billion years. So events that are witnessed prior to 5 billion years should therefore reflect
what was happening when the universe was relatively smaller and dense.
(Also, at the same time, these outbursts occurred prior to billions of years of standard expansion.)

So the observable universe was much smaller, and much more extremely dense, correct?

chris1996 · Nov 11, 2009

I could have been from a nearby quasar that we have not found yet. :?

MeteorWayne · Nov 11, 2009

No, the distance to GRBs is well determined due to the aftergow spectrum; this was at z=6.48. A newer recent GRB (GRB 090423) has been found at an even greater distance of z=8.1.

R1 · Nov 11, 2009

Re: Re:

R1":s0g7mrmk said:
So the observable universe was much smaller, and much more extremely dense, correct?

Actually the universe could not have been smaller, just more extremely dense, I think. :?
This extreme density, I believe, may be an important reason why we see GRBs way back then.

MeteorWayne · Nov 11, 2009

Sorry, that's wrong. The universe was smaller and more dense.

SpeedFreek · Nov 11, 2009

The universe was only around 8 times smaller at that time and we have seen that galaxies had formed at those distances (z~7), so I wouldn't say the universe was extremely dense at that time. There were still large gaps between the galaxies back then!

R1 · Nov 11, 2009

It can get confusing.

I'll have to think some more with this. Thanks, people.

...And we're not talking about 'the observable' universe, but The Universe, correct?

MeteorWayne · Nov 11, 2009

Yes, but both were smaller then

SpaceTas · Nov 14, 2009

Taking sppedfreaks 8 times smaller number, then universe would be 8^3 =512 times denser, but the average distance between galaxies would be 1/8th. Take Milky-Way Andromeda as typical distance (2 million light years) then the typical separation would be 0.25 million light years 250,000 ly. For comparison the LMC is about 157,000 ly. This is close enough for a little bit of tidal interaction between galaxies. Back then there were a lot more collisions (goes with density: factor 512), and so more starburst galaxies and star formation but not wholesale carnage.

Go back another factor of 4 then distances between galaxies get comparable to the size of big galaxies. Then I'd expect galaxy interactions nearly everywhere.

BoJangles2 · Nov 14, 2009

Hrm, as far as I understood it, it’s not the distance between galaxies that is affected by expansion but the distance between galaxy clusters, (which I assume) is that natural cut off between the force of gravity and expansion, i.e. when expansion wins the day.

R1 · Nov 14, 2009

my thought--
I wonder if you may have been thinking about dark energy expansion.
In such case, the added expansion rate of dark energy appears to occur only in large scale emptiness.

SpaceTas · Nov 22, 2009

Galaxy clusters are about the biggest unit in which matter is gravitationally bound. The gravity stops the glaxies inside being spread apart by the expansion.

R1 · Nov 22, 2009

I have heard that the largest things in the universe, The awesome giant Blobs from a long time ago
when the universe was smaller and more dense, could be giant glaxy clusters.

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