Talk:Astrophysical jet

Anon rewrite

On 13 March 2006, this article was massively expanded by 81.76.3.42 (talk · contribs). The expanded version can be viewed via this link. I'm concerned about several aspects of it:

• The narrative tone is completely inappropriate. It reads like an essay or press release, not an encyclopedia article, and fixing this would require another massive rewrite.
• All of this material was added over about 15 minutes. Many paragraphs also look like they've been cut off at the end. This suggests that the material might have been cut-and-pasted from somewhere. The fact that nothing in the added material is wiki-linked would be consistent with cut-and-pasting, or could just be the result of inexperience.
• Many of the conjectures put forward are questionable. Most notable is the speculation that Nemesis, a hypothetical companion star to the Sun, was formed as a result of a polar jet emitted during the Sun's formation.

There's probably quite a bit of material worth folding back in, but it will take a lot of effort to properly source it and present it in an appropriate manner. --Christopher Thomas 08:49, 22 March 2006 (UTC)

Atmospheric Science

• 'Polar Jet' is also a term used in atmospheric science, perhaps a link or disambiguation text can be added? 74.60.11.18 (talk) 08:26, 5 July 2008 (UTC)

Merge

• Oppose merge I don't think it should be merged, the polar jets in Herbig Haro objects are not relativistic. --Keflavich 00:38, 18 April 2006 (UTC)
• Oppose merge - they're not the same thing at all. Worldtraveller 18:52, 18 April 2006 (UTC)

Expansion

The most obvious question left unanswered about polar jets is, what causes them? -- Beland 00:49, 21 April 2007 (UTC)

Jet origin inside the black hole

the current article reads: "whereas if it originates in the black hole it will likely be electron-positron in nature". This is confusing because jets can obviously only form on the 'outside' of the event horizon. 86.177.223.152 (talk) 22:07, 2 August 2011 (UTC)

Changed "in" to "from". This should partially address your concern. — Preceding unsigned comment added by 108.46.201.49 (talk) 23:33, 4 February 2016 (UTC)

Your statement "jets can obviously only form on the 'outside' of the event horizon" assumes the common black hole model with the central object smaller than the Schwarzschild radius. — Preceding unsigned comment added by 100.37.208.238 (talk • contribs)

Title

This article needs a lot of work, but let's start at the beginning. Why on Earth is it called 'polar jet'? Google 'polar jet' and you will see one article in the first few pages using the term in an astrophysical context -- this one. All the rest are meteorological. Nobody in the community calls them 'polar jets'. 'astrophysical jet' would be a lot better if you want a catch-all term; at least that's actually used outside of Wikipedia. Anyone objecting to a rename, please say so.

Mhardcastle (talk) 08:07, 4 March 2014 (UTC)

The article 'Relativistic jet' was merged with this one in August 2012. The mergerer Silent Key proposed it on the Talk:Relativistic jet, got no response, and merged it over the older objections registered above on this talk page. 'Astrophysical jet' would be a much better name for the article. At some point the relativistic version should have its own page again, since it also commonly used in the astronomical literature. StarryGrandma (talk) 01:24, 11 April 2014 (UTC)

OK, as the only comment was in favour, I've renamed the page. Mhardcastle (talk) 19:19, 20 April 2014 (UTC)

Relativistic

I found myself reading this page because of an interest in gamma ray bursts. I don't have any trouble understanding anything in the article except the use of the term "relativistic." I followed up a number of links seeking the answer on Wikipedia, but kept ending up on the page Special Relativity, which didn't help me understand the particular use that was being made of "relativistic." I finally sought enlightenment in the OED and found this lucid definition:

Of an object or a phenomenon: such that differences between the predictions of the theory of relativity and those of Newtonian mechanics or classical electromagnetism are significant, typically because of a speed close to that of light or a strong gravitational field; requiring the theory of relativity for an accurate description.

That made everything instantly clear to me. This definition, or something like it, needs to appear early in the discussion of relativistic jets if it is to make any sense to the nonspecialist.

I am not a scientist, so I would be extremely hesitant to make any changes in such a page. (I do however have a PhD in another field; if a Wikipedia page is incomprehensible to me, it's going to be widely useless.) I'm hoping that someone with the appropriate qualifications will take this on.

Thanks. 03:10, 29 August 2015 (UTC) KC 03:10, 29 August 2015 (UTC) — Preceding unsigned comment added by Boydstra (talk • contribs)

Some changes made to the lede and the body text along the lines of the suggestion above. Mhardcastle (talk) 16:35, 30 August 2015 (UTC)

Both relativistic and ultra-relativistic should be defined. There's a huge Lorentz factor difference between 0.1c and 0.9c ..... I think 0.886c is a Lorentz factor of 2.0 ....... So suggested starting points for this definition: (1) Relativistic velocity defined as > 0.1c ..... and (2) Ultra-relativistic velocity defined as > 0.866c or 0.9c. ....?..108.46.17.166 (talk) 18:31, 31 January 2016 (UTC)BG

More information on the chemical composition of ultra relativistic jets?

This is probably taking liberties but since this is identified as an unsolved problem in physics its probably worth raising some issues here to improve this carefully written article. Probably more information is needed about the chemical composition observations of jets with velocities arbitrarily >0.8c.

If a jet has a velocity >0.8c it should(?) be mostly composed of very tiny particles like electrons, positrons, neutrinos, maybe quarks, other leptons, etc. If full size atoms exist in quantity in an ultra relativistic jet (whew!).... but if full size atoms are present in a >0.8c jet they are probably small in quantity and just going along for the ride. Jets are a source of some cosmic rays? IMHO possibly revealing answers would be had from more chemical composition observations of >0.8C jets from neutron stars, which according to conventional explanations should not have jets roughly >0.5c. Also if >0.8c jets are not mostly composed of the same material as the accretion, what is the reaction and where is the reaction taking place, outside or inside the star? Also if neutron star jets and stellar black hole jets do not always occur simultaneously with accretion it’s a red flag. See these 2 links: http://www.slate.com/blogs/bad_astronomy/2014/02/19/neutron_star_jet_an_exploded_star_creates_a_truly_bizzare_scene.html https://translate.google.com/translate?hl=en&sl=pl&u=https://pl.wikipedia.org/wiki/IGR_J11014-6103&prev=search

According to conventional understanding the jet mechanism is supposed to originate from accretion. How can this neutron star be accreting? It has no binary companion. Was an accreting cloud dragged along with it for 15,000 years? Has this runaway star had this 0.8c jet since it was formed 15,000 years ago? There is some material the neutron star is dragging along but it could very well be side ejecta from the jet or from the star's "boiling" atmosphere. Accretion? Is the glow around the star from accretion radiation or from the star's hot surface or from the jet heating material? In other neutron stars, jet heating of the accretion disk could explain why the Eddington limit is sometimes exceeded. One logical scenario is the 0.8c jet originated within the neutron star all this time, which has interesting implications. There’s an unclear theory about “rotation powered” jets that doesn’t make great sense …… is a spinning magnetic field somehow supposed to suck up material from the poles at >0.8c? AND also somehow convert it into a positron-electron mix? My personal belief for the jet origin is core neutrons in an overweight neutron star simply collapse to ultra-relativistic plasma (maybe electron-positron, or other type plasma) which ejects from the magnetic pole and/or rotation axis. This star probably was an almost-black hole that due to an off-center explosion became instead an overweight runaway neutron star. There are 15 known Accreting Millisecond X-Ray Pulsars (AMXPs), and IGR J11014-6103 is not among them.

If there is complete or almost complete transfer of matter into energy, and if there is charge conservation, an obvious possible reaction is for example a proton changing to a 938 MeV positron, which results in 460 MeV positron-electron plasma. Neutron collapse also results in the same type plasma. This plasma either escapes the star as a jet or if its contained in the star it heats the star. — Preceding unsigned comment added by 100.37.208.238 (talk • contribs) 

Maybe we don't see "black holes" for the same reason we don't see some counter jets: large red shift. Red shift increases rapidly below 2.0 Schwarzschild radius. — Preceding unsigned comment added by 100.37.208.238 (talk) 20:54, 29 March 2016 (UTC)

Possible supernova scenario: What if the protons, neutrons and electrons had already collapsed to positrons and electrons, and then the pressure went high enough to collapse these positrons and electrons? What would they become? Some form of zippy neutrino? — Preceding unsigned comment added by 100.37.208.238 (talk) 20:56, 7 April 2016 (UTC)

The pulsar's speed is reported between 0.001 - 0.003c. ..... That seems rather imprecise.

"One of the biggest mysteries is that we only see these jets in x-rays, there's no radio signature.": http://www.abc.net.au/science/articles/2014/02/19/3948039.htm Intense radio emissions from typical neutron stars are likely caused by a jet from the surface blasting thru accretion material. IGR_J11014-6103 apparently has no accretion material and hence no intense radio emissions.

Elements might be identified by 450-MeV impact frequencies. Lower frequencies?: http://adsabs.harvard.edu/full/1998ASPC..138..119G — Preceding unsigned comment added by 100.37.208.238 (talk • contribs)

IGR_J11014-6103 apparently has no accretion material and hence no intense radio emissions. And the poles don't sweep in earth's direction.If this star had accretion material, a positron-electron jet would cause big GHz radio emissions plus the upper frequencies would be so high=X-ray emissions that could identify the nucleus impacted. — Preceding unsigned comment added by 100.37.208.238 (talk • contribs)

Maybe something from Radio-quiet neutron star can be added to this stars description — Preceding unsigned comment added by 100.37.208.238 (talk) 18:51, 30 March 2016 (UTC)

Numbers in the paragraph IGR J11014-6103 are tentative and need better sourcing, should be updated eventually. There should be a project or club for IGR J11014-6103. 173.56.18.42 (talk) 23:32, 6 February 2016 (UTC)BG

More pieces of the puzzle and possible links

Here are two more possible pieces of the puzzle. One is about compact stars possibly creating a large positron-electron cloud, and the other is about a transitional pulsar neutron star jet > 0.8c: http://www.nasa.gov/centers/goddard/news/topstory/2007/antimatter_binary.html http://www.dailygalaxy.com/my_weblog/2015/08/neutron-star-jets-near-speed-of-light-rival-those-of-black-holes.html Picture is artist rendition. 108.46.17.166 (talk) 23:16, 31 January 2016 (UTC)BG

What are the consequences (for the star) of: "reportedly the jet is only seen in x-rays and there is no radio signature[11], possibly due to absence of accretion material." Could the glow be almost all from a small area? Maybe the glow is mostly from the base of the jet. Likely the glow from the neutron star surface (it would be nice to know the surface temperature) is small compared to the base of the jet.

How much energy is emitted by IGR J11014-6103 each year? Is the power level known? ..... At the measured energy loss rate, what is the ratio of (mass-energy ejected)/(neutron star mass) that the star ejects each year? Today its probably a very small ratio. That could provide an estimate of the jet's future age. Has this jet existed for 15,000 years? Maybe initially it was stronger.

Soon there should be images of a super-nova (prior to explosion) which results in the creation of a black hole or neutron star. Neutron stars are preferably created in this process(?). Thats good because maybe a neutron star is more likely to be a runaway and give good images. Regardless if its a neutron star or black hole it will be good to know how soon after the explosion a jet forms, if a jet forms. — Preceding unsigned comment added by 173.56.18.42 (talk) 16:08, 7 February 2016 (UTC)

IGR J11014-6103 is too long for a name. Any suggestions for a shorter name?

IGR J11014-6103 is apparently a radio quite neutron star. See the wiki article: Radio-quiet neutron star These quiet stars are either runaway or an accretion disk disappeared or old! Changing brightness and temperature?

Note on IGR J11014-6103 relativistic jet

The article should have some statements about the history of IGR J11014-6103. Probably its had this jet and no accretion disk since it was ejected from the supernova 10,000+ years ago. Some source should be willing to suggest something. WHERE does the jet material come from? There’s an unclear theory about “rotation powered” jets that doesn’t make great sense ……is somehow a spinning magnetic field supposed to suck up material from the neutron star's poles and eject it at >0.8c?

My opinion: The relativistic jet from IGR J11014-6103 does not originate from an accretion disk and there hasn't been an accretion disk for 10,000 years. This jet originates from within the star, almost certainly from a core with a partially relativistic center. 173.68.155.15 (talk) 18:32, 10 February 2016 (UTC)BG

After the "Rotating black hole as energy source" section there should be a new section for theories about neutron star jets, focusing on jets near c.173.68.155.15 (talk) 01:58, 22 February 2016 (UTC)BG

Update: Added more theories and explanations, but prior to "Rotating black hole as energy source". Interesting that an electron or positron with a Lorentz factor of about 900 (450 MeV/0.5 MeV) can easily escape a neutron star core (or even a theoretical 1.1 - 1.5 Schwarzschild radius star) and still have most of its energy. Any trace nuclei swept up in this beam would achieve astounding energy. The energy of a swept up nucleus would be (nucleus mass/electron mass) X 450-MeV maximum. Even a small amount of swept up ions would significantly reduce positron and electron energy, but the beam ions would have extraordinary energy .... almost 1TeV protons are easily explained. A powerful jet from within the star could also explain intense radio emissions and why the “Eddington limit” is sometimes exceeded. 68.132.253.173 (talk) 15:00, 23 March 2016 (UTC)BG

If matter is efficiently converted into energy an obvious candidate for the process is proton --> positron + 938 MeV. Some physicists might have mental block to consider a simple reaction like proton --> positron + 938MEV, or neutron --> positron + electron + 938MeV. Note this is a different process than nucleus disintegration in a lab environment such as the Large Hadron Collider where quarks are produced; the core of a neutron star or theoretical 1.2 Schwarzschild radius is a much different environment than a lab vacuum. The speculation about quark stars is understandable. — Preceding unsigned comment added by 100.37.208.238 (talk • contribs)

The simplest process to explain a positron-electron jet with a velocity near c is: Proton --> positron + 938MEV. Or neutron --> positron + electron + 938MeV. Either process gives a 460 MeV positron-electron jet. 460MeV is the maximum energy a positron or electron could achieve by this process, unless some collapse resulting in more neutrinos and radiation, and the remaining positrons and electrons are more energetic. Theoretically it could also be possible that the disintegration of a proton could lead to about 920 cold positron-electron pairs + 1 cold positron, however collapsing cores are very hot high energy places. Also at a pressure not much greater than nucleus collapse, electrons should start to collapse, the result of which is any remaining particles would have a very high energy/rest-mass ratio, like neutrinos. An event like a supernova could contain and collapse positrons and electrons, but it wouldn't contain the neutrinos or radiation. — Preceding unsigned comment added by 100.37.208.238 (talk • contribs)

Spin value for J11014-6103 ? And mass?

Is the spin rate estimated? A good source for this star is: http://www.aanda.org/articles/aa/pdf/2014/02/aa22588-13.pdf

On page 7 there is mention of spin: "which provides Pspin of the order of 0.1 s"

Does this mean the spin is only 0.1 seconds (6 RPM)? I'm hesitant to publish such a low value. 68.132.253.173 (talk) 14:26, 25 March 2016 (UTC)BG

Actually - 0.1s would give 600RPM wich is not that low.95.76.220.229 (talk) 07:31, 30 September 2016 (UTC)Apass

This PSR has been oriented about the same way (except for a brief wobbly period) for at least 45 years and maybe a lot longer. Anyway its pretty stable. Could this star reorient itself occasionally by about 90 degrees? In the expanded image it looks like the jet might have been pointing almost backwards for 3 or 4 years. A source suggested the jet not pointing forwards results in a stronger jet, maybe. Very interesting the low RPM. This star could just be shedding excess weight via the jet and the jet is slowly dying. Maybe its mass was/is a little more than 2.0 solar masses. It would be good to have a mass estimate. Maybe its mass can be figured out some way. — Preceding unsigned comment added by 68.132.253.173 (talk) 16:03, 25 March 2016 (UTC)

Updated with new spin rate estimate of 15.9 Hz. This slow spin rate suggests the 0.8c jet is not rotation powered. And the lack of accretion material means the jet is not accretion powered. Is it neutral to say this in article? Maybe some sources are incorrect referring to PSR J1101-6101 as a rotation powered pulsar.

The jet looks like it more or less has an effective diameter for X-ray production ..... at the point labeled JET in the article expanded image the diameter looks to be over a light year. It might be helpful to have info about jet (or beam) energy density in article.

It might not be possible to determine the mass of this star. Possible scenario: I think when the original star formed it came unusually close to becoming a black hole and the bigger explosion resulted in the high star velocity. Then .... the resulting neutron star was unusually high in mass (> 2SM) and thats the largest factor for the jet size. I think rotation was a smaller factor than excess mass in determining the large size of this jet and in a non spinning neutron star, nuclei collapse starts when the star exceeds about 2.0 solar masses and its a nuclei collapse process that produces the big jets. When this star formed it probably had a much larger 0.999c type jet and the jet intensity and velocity are still decreasing. Eventually the jet velocity will decrease to the point where PSR J1101-6101 would capture jet material, and the star would be surrounded by an electron-positron cloud, except the high ambient wind will blow this cloud mostly away.

Also maybe the name PSR J1101-6101 should be added to the article. Thats the actual name of neutron star in this structure.— Preceding unsigned comment added by 108.30.14.118 (talk) 13:57, 27 March 2016 (UTC)

Maybe the jet didn't change direction and instead the jet shut mostly off for over 3 years. Note early articles/references state "this could be a rapidly spinning neutron star" (a sensible statement). With time this evolved to "is a rapidly spinning neutron star". Now that the rate is calculated the spin rate is actually pretty low. A neutron star might make a jet a touch faster than a typical stellar black hole! A theoretical 5-solar mass, 1.2-Schwarzchild radius “kind of neutron type star” could appear invisible because of gravitational redshift and still have a jet. The contents of this star would be extremely hot.

The total initial energy of the positrons and electrons should be >900MeV + the gravitational energy, but that gravitational energy will be basically lost reaching the surface. Also a Wiki article has started Radio-quiet neutron star. This article could link to it. — Preceding unsigned comment added by 100.37.208.238 (talk • contribs)

See this Utube video of anti-matter production in Sagittarius

It indicates Sagittarius produces 15 billion tons/sec of electron-positron matter:

https://www.youtube.com/watch?v=Sw-og52UUVg — Preceding unsigned comment added by 108.30.14.118 (talk) 19:35, 26 March 2016 (UTC)

PSR J1101-6101 tilted, then roughly 4 years later tilted again?, or did the jet turn on and off?

Whats going on at 1/3rd the jet length? Thoughts: (1) So so maybe: The star shifts orientation. It kind of looks like this star shifted 90 degrees and then in roughly 4 years kind of shifted another 90 degrees to back on or almost the original trajectory. Was the 1st shift sideways or backwards or in between? Whats going on here? Not saying it is but if so it looks like a gyro effect. It looks like there were bursts or something prior to the 2nd shift, or is the 2nd shift actually two 90 degree shifts? IF there was a burst the 2nd shift is probably related. Maybe the poles sometimes shift around erratically? That seems odd. (2) Better maybe: Maybe the jet turned mostly off and then several years later had a burst and/or turned on again? Not saying it is but it kind of looks that way. A burst should not change the stars orientation. If it can be nailed down if this star turned off and on for a few years it would help. Maybe what goes on in the picture has a different explanation.

A lot of analysis went into this image (http://arxiv.org/pdf/1511.01944v1.pdf). IF (a big IF) the jet turned off or mostly off for several years and then back on, this probably wasn't considered in the image processing, and that would change the image a lot. Right now its probably not that important to understand what happened at 1/3 the jet length.

Whats important is to know the MeV of the positrons or electrons in the beam. Having a decent MeV number would result in accurate velocity and Lorentz numbers which would help all other measurements. If the jet is only 0.8c the Lorentz factor is only about 1.7 so this is probably a dying beam. The positrons and electrons in this star's jet have an energy that is only a tiny fraction of 450-MeV.— Preceding unsigned comment added by 100.37.208.238 (talk) 17:04, 28 March 2016 (UTC)

More accurate measurement of positron and electron energy is desirable

It would be great to have a more accurate measurement/calculation of the energy in MeV of the positrons or electrons in this beam. 10% or even 50% accuracy could be very helpful. Having a decent MeV number could result in accurate velocity and Lorentz numbers which would help all other measurements.

This jet is maybe only 0.8c. For a jet with a velocity near c having an accurate positron or electron MeV number is also important.

Again, the simplest process to explain a positron-electron jet with a velocity near c is: Proton --> positron + 938MEV. Or neutron --> positron + electron + 938MeV. Either process produces a positron-electron mix less than roughly 450MeV. A magnetic solenoid and mechanical structure directs the jet. Some of the 450MeV particle energy will be lost heating the star and gravitationally escaping the star core and star surface.

An accreting neutron star of about 2 solar masses probably limits its mass as a result of nuclei collapse in the core producing a jet of <450MeV positron-electron particles. Positron-electron jets from all neutron stars (and black holes) should have under 450MeV particle energy. Many black hole theorists won't like this but positron-electron jets limited to under 450MEV will tell the tale. If positron-electron jets are accelerated magnetically outside the star there is no reason they should be limited to under 450 MeV.

Summary and rounding off numbers: The biggest jets are a positron-electron beam with velocity about c. Consider a process of almost complete conversion of matter to energy: If a proton collapses then what? If charge is conserved the simplest obvious reaction is: proton --> a positron with 938MeV energy, which results in a roughly 450MeV positron-electron mix. Neutron collapse results in a similar 450MeV positron-electron mix. This 450MeV positron-electron plasma both heats the star and normally escapes the star as a jet with a large portion of its initial energy. — Preceding unsigned comment added by 100.37.208.238 (talk • contribs)

Energy a 450MeV positron-electron beam uses escaping a neutron star

Just rambling, this paragraph is probably not important for now... These 900 Lorentz factor positrons and electrons easily have enough energy to escape the neutron star and still have plenty left over. This is probably not the case, but should the gravitational energy used crushing the neutron also be added to the 450-MeV energy of the positron and electrons? Or does it balance out and the escaping beam still wind up with about 450MeV energy? If a 2 solar mass neutron star ejects most newly accreted mass as a jet, the gravitational energy originally used crushing the nucleus should be equal to the escape energy, and the escaping beam would still have roughly 450MeV energy.

After proton collapse there’s an important question about the ratio of leptons to photons. Collapse is happening probably around a particle pressure of (rho)(c^2)/3. At higher energy density such as core collapse in a supernova, positrons and electrons should disintegrate too and all that’s left is neutrinos and gamma rays. At even higher pressures even neutrinos would disintegrate and all that would be left is gamma rays. As these extreme high pressure high energy gamma rays undergo escape from a compact star, there should be massive neutrino and, and the remaining positron-electron pairs might have an energy over 450MeV. Just so long as the total energy from everything resulting from one nuclei collapse is about 938MeV. In a supernova the pressure could be so great that electrons and positrons would collapse, but this does not appear to be the case in jets, and jet positron or electron energy should be about 450MeV maximum.

Probably a >2.0 solar mass neutron star ejects all accretion and a black hole maybe ejects 2/3 of accretion. This might explain black hole growth. — Preceding unsigned comment added by 100.37.208.238 (talk) 16:00, 8 April 2016 (UTC)

Lab production of positron-electron plasma

Looks like they can decently lab produce a 5MeV positron-electron jet, its characteristics can be studied, for example how it radio excites different elements.

See:https://lasers.llnl.gov/workshops/user_group_2012/docs/7.3_chen.pdf

Great opportunity to study the reality of positron-electron beams! Sample quote from above: "Colliding jets can mimic the internal shock of GRBs, allowing study of how energy is transferred to particles".

What should the jet be called, "positron-electron" plasma or "electron-positron" plasma? The general public understands the concept of an electron so starting with electron explains it better to most. But if the actual process is proton collapse then positron-electron is better for understanding the core collapse process. Interesting how in one of the videos above its referred to as "conversion of matter into energy". Maybe this phrase should be added to the article. Nice wording to explain 15 billion tons/second positron-electron plasma production in Sagittarius. A magnetic field can't explain that. What is a logical way to refer to plasma in a star? Proton-electron plasma? Whatever, the article uses both and should really only use one. Did change with: positron-electron.......

Positron-electron plasma could be visualized as the relativistic version of proton-electron plasma, where the proton mass energy has converted to a positron with equivalent kinetic energy. At some enormous pressure electrons and positrons will collapse too, but it looks like nuclei collapse first.

About: "Multiple observations indicate relativistic jets are primarily positron-electron plasma.[27][28] A possible explanation for relativistic neutron star jets is collapsing core nuclei efficiently convert matter into energy[29] by the process of: proton → positron + 938MeV, resulting in a >450MeV positron-electron beam. Trace nuclei swept up in such a beam would achieve an approximate energy of (nucleus mass/electron mass) X 450MeV." From Wiki article: "Antiprotons have been detected in cosmic rays for over 25 years, first by balloon-borne experiments and more recently by satellite-based detectors. The standard picture for their presence in cosmic rays is that they are produced in collisions of cosmic ray protons with nuclei in the interstellar medium, via the reaction (where A represents a nucleus):
p
+ A →
p
+
p
+
p
+ A

Relativistic protons can convert energy into matter by creating 2 kind of protons. Impressive.

Eventually it seems all the positrons and electrons in a jet or beam could annihilate each other, and swept up trace nuclei are all thats left in the beam. This would explain the relativistic protons from space. Iron atoms could have up to 45TeV. If a 45TeV iron atom hits for example a proton, then what? Can you get a 1 TeV proton? Lots of huge energy particles like positrons, electrons, protons, antiprotons, and other leptons could be generated in large quantity by an iron nuclei (for example) jet impacting hydrogen gas clouds in space. Heavy nuclei jets might explain the ancient huge blobs of stuff apparently ejected from the Milky Way's central black hole. Nuclei or positron-electron jets impacting material could explain some intense radio emissions.

Those interested in this might want to see the brief Talk:Gravitational collapse. — Preceding unsigned comment added by 108.30.181.243 (talk) 18:15, 7 June 2016 (UTC)

— Preceding unsigned comment added by 100.37.208.238 (talk) 16:02, 11 April 2016 (UTC)

Temperature estimates for IGR J11014-6103 not available?

I could not find temperature estimates for the neutron star in IGR J11014-6103. This seems odd as there are rough distance estimates to this star, the luminosity should be measurable, and the radius is presumably about 12-km. Even a very rough range could be helpful.

On a side note, maybe the temperature of say a large 1.2 SR black hole (without a jet) could be estimated. This temperature could simply be the escape energy of positron-electron pairs, and could be calculated as a function of radius. For example, if the positron/electron temperature at the star surface exceeded the escape energy of say a 1.2 SR object, a lot of positrons and electrons will escape the star, but due to "red shift" would relatively slowly leave the star. If this positron-electron escape process regulates star temperature/radius, a black hole is probably just a very hot star larger than 1.1 SR that is slowly cooling by emitting red shifted radiation and often a positron-electron wind or jet. But its probably easier and better to first analyze proton collapse in a neutron star at about 2.0 solar mass and 12-km radius.

Perhaps someone could calculate a plot of positron-electron pair escape energy in MeV vs. star radius from 1.1 – 2.0 Schwarzschild radius, both the Newtonian and relativistic calculation. This escape energy could determine the surface temperature and approximate core temperature of the star. 108.30.181.243 (talk) 21:38, 8 June 2016 (UTC)BG

The reference used: "Blandford–Znajek process"

Blandfold presents the case both for jets originating outside the star and inside the star. My interpretation of Blandfold is he thinks jets could originate inside the star! Using him as a reference or argument for jets originating outside the star is very shaky to say the least.

To sum it up: Positron production from proton disintegration causes astrophysical jets

If a 2.0 solar mass neutron star has a radius of about 2.0 Schwarzschild radius, the core pressure reaches about (rho)(c^2)/3, and nuclei collapse could happen. However neutron star is not a good name for this star because its misleading of the process of collapse. Neutrons don't collapse. A neutron is just a combined proton and electron. Protons collapse and electrons are just pushed out of the way. A better name for this star is a proton collapsar or proton convertor or neutron collapsar or neutron convertor.

If there is complete or almost complete transfer of matter into energy, with charge conservation, a logical reaction is protons collapse to positrons with 938MeV energy release, which results in positrons and electrons each having an initial nominal energy of 450MeV (a 450MeV electrically neutral plasma). This plasma either escapes the star as a jet or if it is contained in the star it heats the star. In scientific format:

p⁺
→
e⁺
+ 938MeV

With further collapse positron-electron plasma provides the virial energy needed to support this star and the radius probably never gets smaller than 1.2 Schwarzschild radius.

Trace nuclei swept up in a positron-electron beam could achieve an energy up to (nucleus mass/electron mass) X (450MeV - electron escape energy).

Proton to positron conversion in a star's core explains the initial positron-electron jet composition from neutron stars and black holes (also a bad name), large positron-electron clouds near compact stars, why neutron star mass is limited to about 2.0 SM, TeV cosmic rays, the Eddington limit being exceeded (a jet from within the star heats material outside the star), the main source of radio noise associated with jets (a jet from within the star ionizes material outside the star), and why stars with jets like IGR J11014-6103 are radio quiet. — Preceding unsigned comment added by 108.30.181.243 (talk) 15:23, 11 June 2016 (UTC)

What happens if positrons and electrons in a 450MeV positron-electron beam combine?

Not much info on this. Should it result in 2 gamma rays, each with a lot of forward energy? Or could leptons be involved? — Preceding unsigned comment added by 108.30.212.93 (talk) 17:40, 15 July 2016 (UTC)

Disputed

An anonymous editor (108.30.212.93) has made many changes to this article which are either simply wrong (i.e. a misunderstanding of sources) or look like an attempt to push original, unpublished ideas (WP:NOR), or a combination of the two. I would suggest a revert to a much earlier version and then discussion of each proposed change before it's made. I'll judge the sincerity of the anonymous editor's motivation to improve the article by his/her response to this proposal. In the meantime, I'm tagging the whole article. Can I also remind the anonymous editor that talk pages are not discussion pages. Mhardcastle (talk) 19:00, 26 July 2016 (UTC)

Just added more information to the Jet Composition section from the Blandford paper. I'm sure you will still have objections. Astrophysical jets are an unsolved physics problem. Why not discuss the subject here for a few weeks before you reach judgements? Nobody reading this will mind as long as there is intelligent discussion. At a minimum one or both of us will learn something, and the few people reading this will enjoy it and might even weigh in. Of course material can be added, deleted, or modified to the article and a better more informative article should result. So:

(1) Do you (or anyone else) know of any observational data that can be added (or improved) in the article for the IGR J11014-6103 jet? Some numbers in the article are pretty sloppy. (2) Do you (or anyone else) have any suggestions for what could cause the IGR J11014-6103 jet?? (3) Separately, IF matter collapse happens in a neutron star over about 2.0 solar masses or below about 2.0 Schwarzschild radius, do you have any thoughts about what happens to matter during the contraction process? I recognize that many people committed to the Singularity model (you probably are) are uncomfortable discussing what might happen between 2.0 → 1.1 Schwarzschild radius.

What do you think of this logic sequence for collapse: Is any step incorrect or does any step need sourcing?: (1) Conventional stars in our universe consist primarily of protons, neutrons, and electrons. (2) Neutrons are just combined protons and electrons. (3) When collapse happens, proton collapse occurs prior to electron collapse.

I think you are acting in good faith but will judge your sincerity to improve the article by your response. We can communicate privately if you prefer. — Preceding unsigned comment added by 108.30.212.93 (talk) 23:36, 29 July 2016 (UTC)

OK, a few points:

• This is not the appropriate place to discuss the general topic of jets. This page is for discussion of the Wikipedia article. If you want to discuss this privately it is relatively easy to find out my contact details.
• Our job as Wikipedia editors is to represent the state of the subject in the published literature, NOT to come up with our own ideas about particular objects or about the topic in general. I understand your interest in the jet generation mechanism of IGR J11014 but a Wikipedia page is not the place for half-formed speculation.
• I have now made some changes in order to remove most of the details about IGR J11014 and to make the article flow better, while retaining what I think is the basic (and obvious) point that NS jets are not powered by mechanisms involving black hole rotation. Since IGR J11014 has its own article, you could move some of the deleted material there. Mhardcastle (talk) 10:34, 30 July 2016 (UTC)

Thank you. The article reads better. You are a fussier and better writer. I wrote most of the article on IGR J11014-6103 but neglected it and just updated it. Hope its ok, please check it out ... I’m not a gluten for punishment but prefer things be kept 99% honest. Added a bit of IGR data to the end of the Jet article (the links may need editing). Hope you like it! 108.30.212.93 (talk) 21:32, 31 July 2016 (UTC)BG

Just added the stuff again about lab production of relativistic positron-electron beams, with an explanatory note. Let me know if you disagree. More explanation: At rest, positron-electron recombination typically results in two 0.51MeV gamma rays. For 5MeV positron-electron plasma the particle kinetic energy is about 10X the particle rest mass. Some positron-electron recombination should result but it probably isn't two 0.51MeV gamma rays. A 5MeV positron-electron beam has way ok energy to study possible effects of relativistic positron-electron recombination, and IMHO should indicate what happens in say a 400MeV positron-electron beam.108.30.212.93 (talk) 18:39, 1 August 2016 (UTC)BG

Our conversation hasn't gone anywhere. Hence I wrote a paper about the core nuclei collapse process I think produces jets. Yes, jets from within the star. I think it is correct and shows the black hole singularity model is wrong. If anybody wants to see it, post a note here and you will get a pdf.207.237.87.163 (talk) 18:41, 7 November 2016 (UTC)BG

@Mhardcastle: Mhardcastle points are mostly 100% vaild. This article was a bit of a jumbled mess which to the general reader made little sense, but I have enough background and am neutral in the debate to be able to fix it. There is so much jargon and weasel words, that I had to greatly simplified the text. Most of the text is to detailed for such an article and contained much original work than citing the facts. I have added more recent references here between 2014 and 2017. Whilst there are some points that may or may no be relevant, anonymous users with claiming different ideas to support just a POV will always be removed on any challenge.

I did remove the Dispute template, but if this is a problem, please state this here and discuss it on this Talkpage, Thanks. Arianewiki1 (talk) 05:38, 19 February 2017 (UTC)

Are astrophysical jets an unsolved physics problem?

@The Cube Root Of Infinity: The Cube Root Of Infinity wants to add the template stating "unsolved physics: Why do the accretion discs surrounding certain astronomical objects emit relativistic jets along their polar axes?" I disagree.

While it is true this mechanism is not fully understood this doesn't imply that the mechanisms are not known. I have toned down some of the text to reflect this, especially as the POV seemingly is oriented at a time when black holes were still theoretical unobserved objects. Also as evidence of the sources is already indirect doesn't make astrophysical objects 'unsolved.'

Yet in the article, it is plainly obvious from the age of the cites/references shows this information is out-of-date and desperately requires more modern updates. In many cases they have been greatly superseded. An advisory template should be added to the article advising of these issues and poor actuality in the text presented.

As for the statement that "astrophysical jets are an unsolved physics problem" is certainly wrong. Most astronomical phenomena are not fully understood but knowledge is enough that we have a fair idea what is happening. Should we also add this same template to say stars or other astronomical/astrophysical phenomenae? Arianewiki1 (talk) 00:45, 26 November 2017 (UTC)

A good summary to solve this is 2017 paper: "General relativistic study of astrophysical jets with internal shocks"[1] pdf[2] it says: "Unfortunately, the accretion disc around a BH has not been resolved and only the jet has actually been observed, therefore, studying the visible part of the jet is also an integral part of reconstructing the entire picture, and hence jets, especially the AGN jets are intensely investigated." This is clearly not an 'unsolved physics problem" just an unobserved one (accretion disks are very small in size) whose evidence for is highly likely. This same paper says herefore, acceleration mechanism must be multi-staged and may be result of many accelerating processes like magnetic fields and radiation driving." - naming 10 references! Even Fig.1 pg.8 shows this!

Another is this 2016 paper by Bellan : "Integrated accretion disc angular momentum removal and astrophysical jet acceleration mechanism" [3] pdf [4], which shows experimental support for these mechanisms. (I also do see there is no mention of angular momentum in the current WP article, were formation of the jets is a causal effect that eliminates this from a spinning central source and/or its accretion disk.)

A good modern source is : Beall's 2016 paper "Astrophysical Jets: a review" [5] pdf [6] or his 2015 paper: "A Review of Astrophysical Jets" [7] pdf [8].

Another 2012 review is by Morabito & Meyer "Jets and Accretion Disks in Astrophysics - A Brief Review"[9] pdf [10], and quotes a good introductory line "The existence of accretion disks around many objects found in the universe, with charged particles accelerated to nearly the speed of light along twisted magnetic field lines or relativistic jets are ubiquitous in connection with the formation and death of stars."

Clearly, this further supports my contention that: "astrophysical jets are an unsolved physics problem" is certainly wrong.

Note: We could add this to the article, but this is too complex IMO. I'd also be happy to fix this, but fear I'm too close to the subject to be accused of bias. Arianewiki1 (talk) 01:52, 26 November 2017 (UTC)

Since writing this, I found the source of the contention here was here[11] saying in the deletion: "However, even after decades of work, major theoretical and observational questions about their origin and collimation still remain." The now old quite 2001 Blandford et al. "Compact Objects and Accretion Disks" cite says this [12] pg.11, but the text is not properly quoted, as following this, it says: "There are, generically, two proposed origins for the jet power: the central object (black hole, neutron star or protostar) and the accretion disk. In both cases, the energy derives from differential rotation." This immediately refutes saying: "Why do the accretion discs surrounding certain astronomical objects emit relativistic jets along their polar axes?". This again supports deletion.

I also now see List of unsolved problems in physics, which you should have highlighted. However, the article cited Laing, R. A.; Bridle, A. H. (2013). "Systematic properties of decelerating relativistic jets in low-luminosity radio galaxies". Monthly Notices of the Royal Astronomical Society. 437 (4): 3405–3441. arXiv:1311.1015. Bibcode:2014MNRAS.437.3405L. doi:10.1093/mnras/stt2138. doesn't even say this at all, and only refers to low-luminosity galaxies and not even black holes etc.! (I have now removed this too.) Thanks. Arianewiki1 (talk) 03:05, 26 November 2017 (UTC)

The fact that all these sources talk about "proposed" mechanisms and sources, quite clearly illustrates that this is not a solved problem. The frequency at which workshops discussing the issue are held is another. The mechanism(s) powering jets falls squarely in the same category as the mechanism behind pulsar glitches and (until a couple of months ago) the mechanism behind short gamma-ray bursts. Typically, we have a fairly good guess of some of the main ingredients of a (possible) solution, but no good confirmation of any of the hypotheses. Note, that be presenting problems as solved that are still active topics of discussion may in fact be harmful to the respective fields. Funding committees are not always subject experts and do read these pages.TR 17:01, 26 November 2017 (UTC)

Umm... You make some valid points, but I feel that the solved-unsolved question is really more like partially solved. The implication of 'unsolved' is that some form of new physics is required rather than just knowing the true single or multiple mechanism(s) causing observed phenomena. No new physics is required to explain the astrophysical jet creation, source of energy, etc. Just because an accretion disk has never been seen does this mean it is unsolved? If we apply the same logic, say fusion is the sun's core, just because it hasn't been observed means it is also unsolved? e.g. We see and feel the sunlight but we can't see the mechanism core to test it. Arianewiki1 (talk) 05:51, 27 November 2017 (UTC)

I don't think 'unsolved' implies the need of new physics at all. Just look at some of the examples in the List of unsolved problems in physics. Take fast radio bursts, is their source an open problem in astrophysics? Certainly. Will its resolution involve new physics? It could be, but it is just as likely that is does not. This holds for many other examples on that list as well. Your Sun example also doesn't work so well. The hypothesis that the sun (and star in general) is powered by nuclear fusion has undergone many tests, for example the observation of Solar neutrino's. The situation for jets is quite different, we have several hypothesis about how they could be generated in principle, but we have not yet have smoking gun tests that tells which of those (if any) actually occur and cause the jets we observe. The field is certainly making progress towards solving thus problem, but I doubt anybody in the field would claim that it has been solved. As such, I think we are fine in listing it as an unsolved problem.

I do think that it is likely that this problem will end up being solved very gradually. This means that at some point we will end up in very vague territory whether it solved or not. For now unsolved seems fine though.TR 15:01, 27 November 2017 (UTC)

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