Contradictions in the Distribution of Gamma-Ray Bursts

[Line_112]

TL;DR

I found a discrepancy in the distribution of gamma-ray bursts on the celestial sphere in the figure from the English Wikipedia, and in the figure in the scientific article devoted to gamma-ray bursts.

I previously created a thread here regarding the map of the gamma-ray burst distribution on the celestial sphere, taken from the English Wikipedia article on gamma-ray bursts. It suggests that it is approximately uniform, although not entirely so, as there is still variation in the concentration of points over fairly large areas, which, in my opinion, slightly contradicts the cosmological principle of distribution.

But I was more intrigued by something else: the lack of a decrease in the concentration of points near the galactic equator and the small number of points near the poles. Theoretically, if the bursts are intergalactic, then, as they pass through the relatively dense layers of the galactic disk, the radiation should be strongly absorbed by matter and weaken, which could lead to a decrease in the concentration of points at the equator. At the time, this was just a hypothesis, but now I accidentally stumbled upon confirmation of it, which directly contradicts the caption to the Wikipedia figure.

Quote from the caption to the picture on Wikipedia:
“Positions on the sky of all gamma-ray bursts detected during the BATSE mission. The distribution is isotropic, with no concentration towards the plane of the Milky Way, which runs horizontally through the center of the image.”
Link: https://en.wikipedia.org/wiki/Gamma-ray_burst

Quote from a scientific article that gives a completely different distribution:
“As shown in Figures 3, 4, GRBs are less distributed in the low galactic latitudes. It is very difficult to find GRBs in galactic disk, due to the serious dust extinction, reddening and dense star field in galactic disk. In the high galactic latitudes, there are few transients such as GRB."
Link: https://www.frontiersin.org/journal...nces/articles/10.3389/fspas.2023.1124317/full

There it is given figure, clearly showing a decrease in the concentration of bursts toward the galactic plane, as expected for an extragalactic origin of gamma-ray bursts. Moreover, there are significantly fewer points there than in the Wikipedia figure, as if authors had selected precisely those that correspond to this distribution. This article is from 2023, meaning it's recent, removing any suspicion of insufficient data.

Perhaps I'm misunderstanding something, but this is a rather amusing situation. Is there a reasonable explanation for this?

 

[Cerenkov]

Maybe this article would be helpful?

https://www.frontiersin.org/journal...nces/articles/10.3389/fspas.2023.1124317/full

 

[Ibix]

The review article appears to cover only GRBs since 1997, because it's interested in redshift measurements which it says weren't made prior to that date. It also notes that they're only the GRBs for which redshift could be measured, which seems to be done by looking at the dimmer X-ray and optical afterglow. The wiki article includes all GRBs and notes that the first one was detected in 1967, some thirty years earlier.

So that's obviously why there are more GRBs in the wiki image - it's all of them, while the article includes only (relatively) recent ones that are associated with certain auxiliary observations.

I think it's also the reason for the different distribution. I suspect the bright gamma flash is visible at any latitude, but the dimmer stuff needed for redshift measurement is only visible outside the plane of the galactic disc. So "all GRBs" are uniformly distributed, but "all GRBs for which afterglow redshifts were measured" are uniformly distributed minus the plane of the galaxy.

 

[Line_112]

The review article appears to cover only GRBs since 1997, because it's interested in redshift measurements which it says weren't made prior to that date. It also notes that they're only the GRBs for which redshift could be measured, which seems to be done by looking at the dimmer X-ray and optical afterglow. The wiki article includes all GRBs and notes that the first one was detected in 1967, some thirty years earlier.

So that's obviously why there are more GRBs in the wiki image - it's all of them, while the article includes only (relatively) recent ones that are associated with certain auxiliary observations.

I think it's also the reason for the different distribution. I suspect the bright gamma flash is visible at any latitude, but the dimmer stuff needed for redshift measurement is only visible outside the plane of the galactic disc. So "all GRBs" are uniformly distributed, but "all GRBs for which afterglow redshifts were measured" are uniformly distributed minus the plane of the galaxy.

But then it would have been written differently, for example: In the galactic disk, the afterglow of gamma-ray bursts is very difficult to detect because...
Or: In the galactic disk, host galaxies are very difficult to detect because...

As I read today, gamma radiation is scattered by the Compton effect:
"Today, the Compton effect is used in astrophysics: gamma rays from cosmic objects undergo multiple scattering until their energy drops to X-ray wavelengths, after which they can be analyzed using standard X-ray equipment."
Link: https://elementy.ru/trefil/21117/Effekt_Komptona

That it isn't absorbed, and even passes through matter quite well, but it is transformed into a scattered form, and therefore can no longer be detected by detectors as a point gamma-ray burst with precise coordinates. Just like sunlight passes through clouds, but we can no longer see the Sun itself.

 

[Ibix]

But then it would have been written differently, for example: In the galactic disk, the afterglow of gamma-ray bursts is very difficult to detect because...
Or: In the galactic disk, host galaxies are very difficult to detect because...

Or, by "GRBs" they mean the source of the burst, not just the initial gamma flash. If you want to quibble about wording I suggest you contact the corresponding author and ask them what they meant.

As I read today, gamma radiation is scattered by the Compton effect:

And have you done any maths on the magnitude of the scattering? I mean, sunlight is scattered by the atmosphere and that's why the sky is blue, but it doesn't mean we can't see where the sun is. You need to show that all the gamma would be scattered, not just some of it (like the difference between a clear day and a cloudy day). That means doing the calculations, not just waving your hands a lot.

 

[Cerenkov]

Or we could just cut to the chase and tackle the real issue that is a subtext in this thread?

Line_112's belief that GRB's are of intragalactic origin.

Its not difficult to read between the lines here and see that his 'contradictions' are just him trying to build a case for GRB's being inside the Milky Way.

 

[Ibix]

Its not difficult to read between the lines here and see that his 'contradictions' are just him trying to build a case for GRB's being inside the Milky Way.

Indeed. That's why he needs to do some maths. Gamma ray scattering by the interstellar medium is a key plank in his belief - he needs it to make GRBs occurring outside some relatively small spherical volume "vanish behind the clouds", as it were, so he ends up with an isotropic distribution of visible sources. But he simply asserts that the scattering is strong enough to do this without doing the maths to show that it's a quantitatively plausible argument.

It's worth noting that up to about 25 years ago, serious scientists did consider intra-galactic sources and I gather that there were intra- and extra-galactic camps in the GRB community. I think the isotropy of GRBs was the primary problem for intra-galactic models, although there were others (e.g. a nearby source explosion has to be very "clean" to not leave an obvious long-lived radio source afterwards). New instruments and processes for rapid coordination between existing instruments started to come online in 1997, though, and they started to spot afterglows and host galaxies with redshifts, and there's sometimes correlation with gravitational wave emissions from cosmological distances. The intensity distribution of GRBs (a paucity of weak sources) also suggests we could see GRBs further away than we do see them. That has an easy explanation in cosmological terms (what we see far away is far back in time, and a paucity of dim sources can be explained by proposing that whatever mechanism produces GRBs needed some time to arise) but is hard to explain in a local model. So the intra-galactic models fell by the wayside.

In short, the OP is about 25-30 years late with this idea because there are now too many lines of evidence pointing elsewhere. If he does the maths for his idea himself he might believe it.

 

[Cerenkov]

Just so, Ibix.

But we've visited the idea of a relatively small, spherical volume with an isotropic distribution of GRB's before.

And Line_112 refused to answer my three questions about this small, intragalactic volume.


So, can you please explain how, in defiance of galactic rotation, this sphere could first form?

Can you further explain, how it could persist and resist the rotational forces acting upon it?

Lastly, can you explain why it is we find ourselves at the centre of such a structure at this point in time?



Cerenkov.

 

[Ibix]

Just so, Ibix.

But we've visited the idea of a relatively small, spherical volume with an isotropic distribution of GRB's before.

And Line_112 refused to answer my three questions about this small, intragalactic volume.


So, can you please explain how, in defiance of galactic rotation, this sphere could first form?

Can you further explain, how it could persist and resist the rotational forces acting upon it?

Lastly, can you explain why it is we find ourselves at the centre of such a structure at this point in time?



Cerenkov.

I think you're misunderstanding his model. He's thinking of the interstellar medium as like a dense fog and GRBs as streetlights (or firecrackers going off all across town, I suppose). They're everywhere, but you can only see the ones in a small sphere centered on you because the light from more distant ones is scattered or absorbed.

"Is the interstellar medium dense enough to absorb/scatter all gamma rays over a few hundred light years" isn't a dumb question. However, supporting a wish for the answer to be "yes" by ignoring the many lines of evidence suggesting that the answer is "no" and hinting at scientific misconduct in the review paper while apparently not even having done a back of the envelope calculation is a different matter, IMO.

 

[Cerenkov]

I think you're misunderstanding his model. He's thinking of the interstellar medium as like a dense fog and GRBs as streetlights (or firecrackers going off all across town, I suppose). They're everywhere, but you can only see the ones in a small sphere centered on you because the light from more distant ones is scattered or absorbed.

Ok, so I envisaged his model incorrectly. Thanks for pointing that out.

"Is the interstellar medium dense enough to absorb/scatter all gamma rays over a few hundred light years" isn't a dumb question. However, supporting a wish for the answer to be "yes" by ignoring the many lines of evidence suggesting that the answer is "no" and hinting at scientific misconduct in the review paper while apparently not even having done a back of the envelope calculation is a different matter, IMO.

Indeed.

Go too far down the road of ignoring the evidence and one comes to the realm of conspiracy theories.

Then the scientists who study GRBs aren't just incompetent and wrong, or guilty of misconduct.

They are perpetrating disinformation for some nefarious purpose.

 

[Line_112]

And have you done any maths on the magnitude of the scattering? I mean, sunlight is scattered by the atmosphere and that's why the sky is blue, but it doesn't mean we can't see where the sun is. You need to show that all the gamma would be scattered, not just some of it (like the difference between a clear day and a cloudy day). That means doing the calculations, not just waving your hands a lot.

But the weakest flares no longer pass through the scattering medium of the galactic disk. Therefore, their number at the equator should be smaller, meaning anisotropy in the distribution across the celestial sphere should result. For example, we would see the Sun through thin clouds, but not the stars. Since relative isotropy exists, it means that flares are highly likely to originate within the galaxy itself, not beyond its boundaries.

 

[Line_112]

The intensity distribution of GRBs (a paucity of weak sources) also suggests we could see GRBs further away than we do see them. That has an easy explanation in cosmological terms (what we see far away is far back in time, and a paucity of dim sources can be explained by proposing that whatever mechanism produces GRBs needed some time to arise) but is hard to explain in a local model. So the intra-galactic models fell by the wayside.

The lack of weak bursts in the overall statistics is easily explained by the fact that, given a constant gamma-ray burst power, most of them will occur within the galaxies disk, that is, not very far from us. Further away, in the halo, the density of stars drops sharply, so few bursts will arrive from far away, resulting in a natural deficit of weak (i.e., distant) bursts. The cosmological explanation is questionable, as there is reason to believe that galaxies have existed for at least hundreds of billions of years. This is supported by the large-scale structure of the Universe (which would have taken a very long time to form), as well as structures billions of light-years across, the small angular size of distant galaxies, the discovery of increasingly distant galaxies, supermassive black holes at the "edge of the Universe," and other arguments.

 

[Line_112]

I think the isotropy of GRBs was the primary problem for intra-galactic models, although there were others (e.g. a nearby source explosion has to be very "clean" to not leave an obvious long-lived radio source afterwards).

Even ignoring the Milky Way's disk, the map doesn't have a very isotropic distribution. I've already learned intuitively to recognize where random statistics hold and where they don't. The gamma-ray burst map features vast regions with clearly elevated and depressed concentrations of markers, which contradicts a random, uniform distribution. The likelihood that this is a coincidence is, in my opinion, low. That is, anisotropy does exist. And gamma-ray bursts don't require explosions. If they're intragalactic, they're likely a technosignature—the acceleration of a spacecraft by a directed thermonuclear explosion. The energy would spread practically as a beam from the spacecraft's exhaust.

 

[Ibix]

there is reason to believe that galaxies have existed for at least hundreds of billions of years.

You "have reason to believe" that galaxies are at least seven times older than the universe they exist in? Out of morbid curiosity, what is that reason?

 

[Cerenkov]

But the weakest flares no longer pass through the scattering medium of the galactic disk. Therefore, their number at the equator should be smaller, meaning anisotropy in the distribution across the celestial sphere should result. For example, we would see the Sun through thin clouds, but not the stars. Since relative isotropy exists, it means that flares are highly likely to originate within the galaxy itself, not beyond its boundaries.

Values? Data? Evidence?

Constructing an argument is all very well but science doesn't proceed just by well made (or poorly made) arguments. It proceeds by having those arguments tested by observations. Which yield evidence and data and numerical values which can cited by the argument-maker to support their argument.

Do you have any?

 

[Cerenkov]

The lack of weak bursts in the overall statistics is easily explained by the fact that, given a constant gamma-ray burst power, most of them will occur within the galaxies disk, that is, not very far from us. Further away, in the halo, the density of stars drops sharply, so few bursts will arrive from far away, resulting in a natural deficit of weak (i.e., distant) bursts. The cosmological explanation is questionable, as there is reason to believe that galaxies have existed for at least hundreds of billions of years. This is supported by the large-scale structure of the Universe (which would have taken a very long time to form), as well as structures billions of light-years across, the small angular size of distant galaxies, the discovery of increasingly distant galaxies, supermassive black holes at the "edge of the Universe," and other arguments.

Sources? Citations? Published papers?

Presumably you can back up these assertions by providing links to sites that support your claims?

 

[Cerenkov]

Even ignoring the Milky Way's disk, the map doesn't have a very isotropic distribution. I've already learned intuitively to recognize where random statistics hold and where they don't. The gamma-ray burst map features vast regions with clearly elevated and depressed concentrations of markers, which contradicts a random, uniform distribution. The likelihood that this is a coincidence is, in my opinion, low. That is, anisotropy does exist. And gamma-ray bursts don't require explosions. If they're intragalactic, they're likely a technosignature—the acceleration of a spacecraft by a directed thermonuclear explosion. The energy would spread practically as a beam from the spacecraft's exhaust.

And you are qualified to make these judgments in what way?

You'll grace us with these qualifications that you've earned from reputable institutions, yes?

 

[Line_112]

And you are qualified to make these judgments in what way?

You "have reason to believe" that galaxies are at least seven times older than the universe they exist in? Out of morbid curiosity, what is that reason?

Galaxies can appear and die. But overall, what we call the Universe must be much older than 13 billion years, since otherwise many things don't add up. According to steady-state hypotheses, the beginning, if it happened, was very long ago, meaning galaxies existed even before 13-14 billion years ago. The most striking confirmation, as I wrote in the comment above, is the large-scale structure of the Universe, which clearly took more than 13 billion years to form. For example, Andromeda, as reported online, may collide with the Milky Way in 8-10 billion years, and it's only about 2 million light-years away. The average size of voids is 130 million light-years, and supervoids are much larger. 130/2 = 65 is the distance to Andromeda in a typical void. 10 billion years x 65 = 650 billion years – that's how long it would take Andromeda to simply cross a typical, average-sized void. This means that the formation of a medium-sized void must have taken at least a comparable amount of time, meaning at least hundreds of billions of years.

 

[Bandersnatch]

The voids, like all large scale structure, are subject to expansion as they evolve, especially rapid early on.
Numerical simulations were run (eg. Illustris, Millenium) and the formation of structure under the LCDM tracks what is observed.
One can only view the steady state as a contender for LCDM if they ignore all the evidence in the latter's favour.
And in any case, promotion of defunct hypotheses, like steady state is in breach of forum rules. So if you want to keep discussing physics here, maybe change the tack.

 

[Cerenkov]

Galaxies can appear and die. But overall, what we call the Universe must be much older than 13 billion years, since otherwise many things don't add up. According to steady-state hypotheses, the beginning, if it happened, was very long ago, meaning galaxies existed even before 13-14 billion years ago. The most striking confirmation, as I wrote in the comment above, is the large-scale structure of the Universe, which clearly took more than 13 billion years to form. For example, Andromeda, as reported online, may collide with the Milky Way in 8-10 billion years, and it's only about 2 million light-years away. The average size of voids is 130 million light-years, and supervoids are much larger. 130/2 = 65 is the distance to Andromeda in a typical void. 10 billion years x 65 = 650 billion years – that's how long it would take Andromeda to simply cross a typical, average-sized void. This means that the formation of a medium-sized void must have taken at least a comparable amount of time, meaning at least hundreds of billions of years.

I'm sorry Line_112, but even though I see you cited me, I can't see any answer to any of my questions in this reply. Perhaps you didn't see them or perhaps you would prefer to ignore them? But giving you the benefit of the doubt, here they are again.

Values? Data? Evidence? Do you have any?

Sources? Citations? Published papers?

And you are qualified to make these judgments in what way?

You'll grace us with these qualifications that you've earned from reputable institutions, yes?


Rhetorical question...
I wonder if you can ignore me longer than I can keep asking you for answers?

Cerenkov.

 

[Line_112]

And in any case, promotion of defunct hypotheses, like steady state is in breach of forum rules.

In any case, a deficit of weak bursts also occurs with an intragalactic origin. The combination of an intragalactic origin and the presence of a high redshift clearly indicates their artificial nature, as natural intragalactic objects cannot move so quickly, while artificial ones can be deliberately accelerated to high speeds for interstellar travel.

 

[Line_112]

Sources? Citations? Published papers?

I publish my work on my online channels [redacted by mentors]
The advantage of this type of publication is that articles can be edited and expanded upon as new ideas arise and new information becomes available.

And you are qualified to make these judgments in what way?

If I consider them justified, then why not?

 

[Ibix]

If I consider them justified, then why not?

Because it's not science, it's just the same "I don't understand the science but I know it's wrong and I know better" methodology of moon hoaxers and flat earthers applied to a different field, with exactly the same results.

 

[berkeman]

Thread is closed for Moderation.

 

[Nugatory]

The thread will remain closed.