Researchers pinpoint origin of photons in mysterious gamma-ray bursts

exploding star
Credit: CC0 Public Domain

Scientists from the RIKEN Cluster for Pioneering Research and collaborators have used simulations to show that the photons emitted by long gamma-ray bursts, among the most energetic events to take place in the universe, originate in the photosphere—the visible portion of the "relativistic jet" that is emitted by exploding stars.

Gamma-ray bursts are the most powerful electromagnetic phenomenon observed in the universe, releasing as much energy in just a second or so as the sun will release over its entire lifetime. Though they were discovered in 1967, the mechanism behind this enormous release of energy long remained mysterious. Decades of studies finally revealed one type called long bursts originates from relativistic jets of matter ejected during the death of massive stars. However, exactly how gamma-rays are produced from the jets is still unknown.

The current research, published in Nature Communications, began from a discovery called the Yonetoku relation, which was originally made by one of the authors of the paper. This relation between the spectral peak energy and peak luminosity of GRBs is the tightest correlation found so far in the properties of GRB . It thus provides the best diagnostic so far for explaining the emission mechanism, and the strictest test for any model of gamma-ray bursts. Incidentally, the relationship also meant that long could be used as a "standard candle" for measuring distance, allowing astronomers to peer further into the past than type 1A supernovae, which are commonly used today, but are much dimmer. This would make it possible to gain insights into the history of the universe, and could produce insights into mysteries such as dark matter and dark energy.

Researchers pinpoint origin of photons in mysterious gamma-ray bursts
3D profile with a 2D slice taken through the midplane of the simulation. The jet axis (dashed arrow) and our viewing angle from Earth (dotted line) are also shown. Credit: Adapted from Ito et al. (2019) Nature Communications

Using performed on several supercomputers, including Aterui of the National Astronomical Observatory of Japan, Hokusai of RIKEN, and Cray xc40 of the Yukawa Institute for Theoretical Physics, the group focused on the so-called "photospheric emission" model, one of the leading models for the emission mechanism of GRBs. This model postulates that the photons visible on earth are emitted from the photosphere of the relativistic jet. As the jet expands, it becomes easier for photons to escape from within it, since there are fewer objects available to scatter the light. Thus, the "critical density" —the place where it becomes possible for the photons to escape— moves downward through the jet to material that was originally at higher and higher densities.

To test the validity of the model, the team set out to test it in a way that took into account the global dynamics of relativistic jets and radiation transfer. By using a combination of three-dimensional relativistic hydrodynamical simulations and radiation transfer calculations to evaluate photospheric emissions from a relativistic jet breaking out of massive star envelope, they were able to determine that at least in the case of long GRBs—the type associated with such collapsing massive stars—the worked. Their simulations revealed that the Yonetoku relation could be reproduced as a natural consequence of the jet-stellar interactions. "To us," says Hirotaka Ito of the Cluster for Pioneering Research, "this strongly suggests that photospheric emission is the emission mechanism of GRBs."

Researchers pinpoint origin of photons in mysterious gamma-ray bursts
Graph comparing observations and simulation results to the Yonetoku relation. The different simulations use different jet powers and times. Credit: Adapted from Ito et al. (2019) Nature Communications

He continues, "While we have elucidated the origin of the photons, there are still mysteries concerning how the relativistic jets themselves are generated by the collapsing stars. Our calculations should provide valuable insights for looking into the fundamental mechanism behind the generation of these tremendously powerful events."


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More information: Nature Communications (2019). DOI: 10.1038/s41467-019-09281-z
Journal information: Nature Communications

Provided by RIKEN
Citation: Researchers pinpoint origin of photons in mysterious gamma-ray bursts (2019, April 3) retrieved 25 May 2019 from https://phys.org/news/2019-04-photons-mysterious-gamma-ray.html
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Apr 03, 2019
Incidentally, the relationship also meant that long gamma-ray bursts could be used as a "standard candle" for measuring distance,....


That could be very useful.

Apr 03, 2019
The "Dark Energy Dialogue," now on YouTube, provides clarity and insight into the dark energy problem, as well as expositions of two plausible solutions. Link: https://youtu.be/4goInwbOix4

Apr 03, 2019
The "Dark Energy Dialogue," now on YouTube, provides clarity and insight into the dark energy problem, as well as expositions of two plausible solutions. Link: https://youtu.be/4goInwbOix4


Not sitting through youtube vids that may turn out to be bollocks. Any associated papers in the scientific literature?

Apr 03, 2019
releasing as much energy in just a second or so as the sun will release over its entire lifetime


That is truly a phenomenal amount of energy almost impossible to comprehend.

Apr 03, 2019
They admit the GRB's are caused by electric currents, but they don't understand how or why.

Apr 03, 2019
The "Dark Energy Dialogue," now on YouTube, provides clarity and insight into the dark energy problem, as well as expositions of two plausible solutions. Link: https://youtu.be/4goInwbOix4


Not sitting through youtube vids that may turn out to be bollocks. Any associated papers in the scientific literature?
I'm going with "no".

And hey, phsorg, get some English. The double quotes go after the period. Duhhhh ummmm.

Apr 04, 2019
They admit the GRB's are caused by electric currents, but they don't understand how or why.


They say no such thing. Quote the relevant text from the paper where they invoke electric currents.

Apr 04, 2019
They admit the GRB's are caused by electric currents, but they don't understand how or why.


They say no such thing. Quote the relevant text from the paper where they invoke electric currents.

First sentence of the abstract moron;
"Long duration gamma-ray bursts (GRBs), the brightest events since the Big Bang itself, are believed to originate in an ultra-relativistic jet breaking out from a massive stellar envelope."
The "ultra-relativistic jet" is an electric current.

Apr 04, 2019
They admit the GRB's are caused by electric currents, but they don't understand how or why.


They say no such thing. Quote the relevant text from the paper where they invoke electric currents.

First sentence of the abstract moron;
"Long duration gamma-ray bursts (GRBs), the brightest events since the Big Bang itself, are believed to originate in an ultra-relativistic jet breaking out from a massive stellar envelope."
The "ultra-relativistic jet" is an electric current.


No it isn't. You are making things up. Again. Stick to misinterpreting mythology. Science really isn't your thing. Download paper. Word search for 'electric' - zilch. Word search for 'current' - a number of hits, but all relating to - 'Current; belonging to the present time; happening or being used or done now.'

Stop making things up.

Apr 04, 2019
Because these plasma ignoramuses don't understand what they are looking at doesn't change the facts.
Measurement of the Electric Current in a Kpc-Scale Jet
https://arxiv.org...106.1397

Apr 04, 2019
Because these plasma ignoramuses don't understand what they are looking at doesn't change the facts.
Measurement of the Electric Current in a Kpc-Scale Jet
https://arxiv.org...106.1397


Lol. A paper that starts with the sentence; "A fundamental conundrum of astrophysical jet
models is how energy is extracted from the accretion flow close to the black hole event horizon."

So, you agree that these hypothesised, induced currents are generated by the BH?

Apr 04, 2019
The paper primarily discusses the the electric currents of the jets, and yes it is a conundrum as to how your faerie tale BH creates these jets. What is not a conundrum is how plasmoids are known to form jets, that has been clearly spelled out in the scientific literature.

Apr 04, 2019
The paper primarily discusses the the electric currents of the jets, and yes it is a conundrum as to how your faerie tale BH creates these jets. What is not a conundrum is how plasmoids are known to form jets, that has been clearly spelled out in the scientific literature.


Nope, you had a bunch of rubbish from 1985, in an irrelevant and inappropriate journal. Which fails to agree with observation. It is a non-hypothesis. And it isn't that much of a mystery as to how the jets are formed;

Magnetic Fields in Astrophysical Jets: From Launch to Termination
Pudritz, A. e. et al.
https://arxiv.org...2073.pdf

Nor, indeed, how some of them may carry currents from the accretion disk into the jet.


Apr 04, 2019
The paper primarily discusses the the electric currents of the jets, and yes it is a conundrum as to how your faerie tale BH creates these jets. What is not a conundrum is how plasmoids are known to form jets, that has been clearly spelled out in the scientific literature.


What literature?

Apr 04, 2019
@Forum.

Observing the following exchange impartially:

@cantdrive claimed:
The "ultra-relativistic jet" is an electric current.


@Castrogiovanni replied:
No it isn't. You are making things up.


@cantdrive85 then produced this mainstream link supporting his initial claim:
Measurement of the Electric Current in a Kpc-Scale Jet
https://arxiv.org...106.1397


Instead of fairly admitting error, @Castrogiovanni attempted to change the subject (ie, from Electric Currents) to BHs, thusly:
So, you agree that these hypothesised, induced currents are generated by the BH?


Impartial observers may conclude that @Castrogiovanni still improperly implies such Electric Currents are 'hypothetical'; and that he trying to dodge his own fair-debate responsibility of admitting that he was in error when he claimed @cantdrive was in error.

Just observing the exchange objectively and fairly. Nothing more. Thanks.

Apr 04, 2019
The paper primarily discusses the the electric currents of the jets, and yes it is a conundrum as to how your faerie tale BH creates these jets. What is not a conundrum is how plasmoids are known to form jets, that has been clearly spelled out in the scientific literature.


Nope, you had a bunch of rubbish from 1985, in an irrelevant and inappropriate journal. Which fails to agree with observation. It is a non-hypothesis. And it isn't that much of a mystery as to how the jets are formed;

Magnetic Fields in Astrophysical Jets: From Launch to Termination
Pudritz, A. e. et al.
https://arxiv.org...2073.pdf

Nor, indeed, how some of them may carry currents from the accretion disk into the jet.


Amusingly, jonesdumb links to an article that confirms the jets are electric currents formed by the z-pinch process.

Apr 04, 2019
Just observing the exchange objectively and fairly. Nothing more. Thanks.


No, you are observing it in the light of ignorance and misunderstanding. Not all jets are necessarily current carrying. Which is why I linked to the paper that I did. You might learn something if you actually read it. The paper cd linked was describing an emission from an AGN. The above article is about a GRB, and they are believed to originate from supernovae of massive stars that then form BHs and neutron stars. We saw one after the recent neutron star merger. Not at all the same thing.

Apr 04, 2019
Amusingly, jonesdumb links to an article that confirms the jets are electric currents formed by the z-pinch process.


Amusingly, you linked to a paper that has nothing to do with GRBs.

Apr 04, 2019
Amusingly, jonesdumb links to an article that confirms the jets are electric currents formed by the z-pinch process.


Amusingly, you linked to a paper that has nothing to do with GRBs.

Yet the paper you linked indicates that all these jets at various scales are essentially the same. And once again you are changing the subject.
And RC's assessment is accurate, the accusations of ignorance needs to be redirected at yourself.

Apr 04, 2019

Yet the paper you linked indicates that all these jets at various scales are essentially the same. And once again you are changing the subject.


In which case you either didn't read the paper or, more likely, didn't understand it. And again, what has any of this got to do with an exploding star?

Apr 04, 2019
This photosphere is this star's outer shell from where light is radiated

Gamma-ray bursts originate in this photosphere
release in a micro second this suns total output over 5 billion years
then
theory predicts
what remains collapses to a blackhole
as this star is turning mass into energy
this Sun is losing 4million tons a second
as in 4.5 billion years
equates to 5.7x10+26kg in as little as a micro second
or
1/3,333 of the total mass of this Sun
when it's put like this
an exploding star loosing 1/3,000 of its mass
is
Not so extraordinary after all

Apr 04, 2019
RealityCheck
Forum.
Observing the following exchange impartially
cantdrive claimed
The ultra-relativistic jet is an electric current

Castrogiovanni replied
No it isn't You are making things up

cantdrive85 then produced this mainstream link supporting his initial claim
Measurement of the Electric Current in a Kpc-Scale Jet
https://arxiv.org...106.1397

Instead of fairly admitting error Castrogiovanni attempted to change the subject from Electric Currents to BHs thusly
So, you agree that these hypothesised induced currents are generated by the BH

Impartial observers may conclude that Castrogiovanni still improperly implies such Electric Currents are hypothetical and that he trying to dodge his own fair-debate responsibility of admitting that he was in error when he claimed cantdrive was in error
Just observing the exchange objectively and fairly Nothing more Thanks

The art of Obfuscation, Well spotted RealityCheck

Apr 04, 2019
@Castrogiovanni.
Just observing the exchange objectively and fairly. Nothing more. Thanks.
No, you are observing it in the light of ignorance and misunderstanding. Not all jets are necessarily current carrying. Which is why I linked to the paper that I did. You might learn something if you actually read it. The paper cd linked was describing an emission from an AGN. The above article is about a GRB, and they are believed to originate from supernovae of massive stars that then form BHs and neutron stars. We saw one after the recent neutron star merger. Not at all the same thing.
Mate, a relativistic polar jet of plasma is ELECTROMAGNETIC 'stuff' REGARDLESS of 'provenance'. The same currents/countercurrents acknowledged in that link occur in/across/along ALL vast plasma jet 'columns'. The FAST ELECTRON phenomena I long ago pointed out to you makes it impossible for there to NOT be such currents arising in any plasma jet feature. Rethink your 'arguments', @Castro.

Apr 04, 2019
Knowing when not to be a party pooper, RealityCheck

But then RealityCheck, old bean
this feud
between cantdrive and dear old jonesy
has
been fought out in these quantum fluctuations for Aeons
so
RealityCheck, this is their art of conversation
because
RealityCheck, you have to sometimes give a little slack
especially
with this new Spartanisation
this toing and froing
has become a way of life between cant and jonesy
so
remember this RealityCheck, be critical
but
Don't spoil the party

Apr 04, 2019
ELECTROMAGNETIC 'stuff' REGARDLESS of 'provenance'. The same currents/countercurrents acknowledged in that link occur in/across/along ALL vast plasma jet 'columns'. The FAST ELECTRON phenomena I long ago pointed out to you makes it impossible for there to NOT be such currents arising in any plasma jet feature. Rethink your 'arguments', @Castro.


Stop talking crap, you loon. I do not need to listen to cranks like you when it comes to science.

Apr 04, 2019
@Castrogiovanni.
ELECTROMAGNETIC 'stuff' REGARDLESS of 'provenance'. The same currents/countercurrents acknowledged in that link occur in/across/along ALL vast plasma jet 'columns'. The FAST ELECTRON phenomena I long ago pointed out to you makes it impossible for there to NOT be such currents arising in any plasma jet feature. Rethink your 'arguments', @Castro.
Stop talking crap, you loon. I do not need to listen to cranks like you when it comes to science.
So, mate, exactly which mainstream science are you denying? Is it the electromagnetic phenomena/features under discussion? Or maybe the FAST ELECTRON phenomena/currents arising in all high-energy electromagnetic phenomena features, like relativistic plasma jets of ANY 'provenance'? Really, @Castro, if you are ever to live down and shake off your "@jonesdave 'reputation/legacy' here at PO, you need to be more objective and less rude. Thanks.

Apr 04, 2019
^^^^^Save yourself the time and effort. You are on block.

Apr 04, 2019
^^^^^Save yourself the time and effort. You are on block.

***IOW, jonesdumb doesn't like the taste of the ***egg on his face*** so he will try to ignore it.***

Apr 04, 2019
^^^^^Save yourself the time and effort. You are on block.

***IOW, jonesdumb doesn't like the taste of the ***egg on his face*** so he will try to ignore it.***


Ignore what? Jets from BHs and supernovae? You don't believe in either of those things, so why are you commenting on the evidence for their existence?

Apr 04, 2019
The "Dark Energy Dialogue," now on YouTube, provides clarity and insight into the dark energy problem, as well as expositions of two plausible solutions. Link: https://youtu.be/4goInwbOix4


Not sitting through youtube vids that may turn out to be bollocks. Any associated papers in the scientific literature?


Ahmed Ali and Saurya Das, 2015

Apr 05, 2019
^^^^^Save yourself the time and effort. You are on block.

***IOW, jonesdumb doesn't like the taste of the ***egg on his face*** so he will try to ignore it.***


Ignore what? Jets from BHs and supernovae? You don't believe in either of those things, so why are you commenting on the evidence for their existence?

Or change the subject.

That jets are there is not a prediction of BH's, they were quite unexpected in fact. And how supposed BH's create the jets is pure conjecture, actually conjecture stacked upon conjecture.

That supernovae occur is not questioned, your faerie tale conjecture of the lifestyles of the stars and dark/strange matter is what is being challenged. Clearly explosive events occur, not at all unexpected in plasma circuits.

Apr 05, 2019
^^^^^Save yourself the time and effort. You are on block.

***IOW, jonesdumb doesn't like the taste of the ***egg on his face*** so he will try to ignore it.***


Ignore what? Jets from BHs and supernovae? You don't believe in either of those things, so why are you commenting on the evidence for their existence?


Or change the subject.

That jets are there is not a prediction of BH's, they were quite unexpected in fact. And how supposed BH's create the jets is pure conjecture, actually conjecture stacked upon conjecture.

That supernovae occur is not questioned, your faerie tale conjecture of the lifestyles of the stars and dark/strange matter is what is being challenged. Clearly explosive events occur, not at all unexpected in plasma circuits.


Just link to where this crap is written up, yes? Because you haven't got a clue.

Apr 05, 2019
@cant

So no literature, I see.

Apr 05, 2019
@cant

So no literature, I see.


http://lppfusion....No-1.pdf

Apr 05, 2019
@cant

So no literature, I see.


http://lppfusion....No-1.pdf


A bunch of failed junk from 1985 in an irrelevant and inappropriate journal.

Apr 05, 2019
@cant

So no literature, I see.


http://lppfusion....No-1.pdf


So that is where 85 comes from.

Apr 05, 2019
@cant

So no literature, I see.


http://lppfusion....No-1.pdf


So that is where 85 comes from.


Yep. He hypothesised that the plasma was from a protogalactic plasma cloud. We now know that they are SMBHs residing in elliptical galaxies. The fact that the hypothesis has long since been shown to be wrong has no effect on the EU types.

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