Talk:Astrophysical jet

message: On 13 March 2006, this article was massively expanded by . 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)
thread_title: Anon rewrite

message: * '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)
thread_title: Atmospheric Science

message: *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)
thread_title: Merge

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

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

message: 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)
replies: text: 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)
thread_title:  Relativistic 

message: 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)
thread_title:   More information on the chemical composition of ultra relativistic jets? 

message: 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)
thread_title:  More pieces of the puzzle and possible links 

message: 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)
thread_title:  Note on IGR J11014-6103 relativistic jet 

message: 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)
thread_title:  See this Utube video of anti-matter production in Sagittarius  

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

message: 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)
thread_title:  Energy a 450MeV positron-electron beam uses escaping a neutron star  

message: 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):  +  A →  +  +  + 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)
thread_title:  Lab production of positron-electron plasma 

message: 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)
thread_title:  Temperature estimates for IGR J11014-6103 not available? 

message: 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:
  →    +  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)
thread_title:  To sum it up: Positron production from proton disintegration causes astrophysical jets 

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

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