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SRH
2012-Jul-09, 01:30 AM
For galaxies that have 2 relativistic jets streaming out of its center, what do we know about their composition?

-is it mostly matter or energy or both?
-which elements?
-which sub-atomic particles?
-any other known characteristics (mass, charge, spin, velocity, spectrum, luminosity? etc.)?

If there is not a definitive answer with standard theory, could you please tell me what some of the competing theories are saying about the composition of the matter and or energy seen in relativistic jets?

Thanks.

Tensor
2012-Jul-09, 02:01 AM
For galaxies that have 2 relativistic jets streaming out of its center, what do we know about their composition?

-is it mostly matter or energy or both?
-which elements?
-which sub-atomic particles?
-any other known characteristics (mass, charge, spin, velocity, spectrum, luminosity? etc.)?

If there is not a definitive answer with standard theory, could you please tell me what some of the competing theories are saying about the composition of the matter and or energy seen in relativistic jets?

Thanks.

The answers all depend on the several different variables. This paper (http://arxiv.org/pdf/1104.0006v1.pdf) explains the different methods and amount of power and energy that can come from those different methods.

WayneFrancis
2012-Jul-09, 02:11 AM
From my understanding we don't have a good understanding of exactly what the jets are comprised of. We can make some speculations by the physics thought to be occurring near the event horizon where matter is being accreted before most of it is being channelled to the poles. Most of the material in the accretion disk will be hydrogen and helium. The energies will at least strip off electrons. There seems to be nucleosynthesis occurring in the disks. As to how much of that is channelled into the jets compared to the already existing hydrogen and helium I'm not sure. There is a lot of energy in the jets. They are a very strong source of radio emissions. The jets are most likely a plasma for a very long distance do to the energy levels involved. Some jets can be thousands of light years in length.

I don't know any real competing theories besides accretion disks around SMBHs. The different theories I've read about all involve the magnetic fields of the black holes causing the jets in a similar way the Earth's magnetic field causes the aurora borealis.

SRH
2012-Jul-09, 02:36 AM
I don't know any real competing theories besides accretion disks around SMBHs. The different theories I've read about all involve the magnetic fields of the black holes causing the jets in a similar way the Earth's magnetic field causes the aurora borealis.

Do you remember the names of the authors or have any links on this? thanks in advance.

WayneFrancis
2012-Jul-09, 06:15 AM
Roger Penrose is one of them and Roger Blandford is another. Hmmm Both named Roger. I'm not sure who's idea holds more weight. I was exposed to Blandford via the SETI talks.

Tensor
2012-Jul-09, 06:41 AM
Do you remember the names of the authors or have any links on this? thanks in advance.

Did you look at the link to the paper I provided? It does, after all, have 96 other papers that you can look up.

tusenfem
2012-Jul-09, 06:45 AM
Roger Penrose is one of them and Roger Blandford is another. Hmmm Both named Roger. I'm not sure who's idea holds more weight. I was exposed to Blandford via the SETI talks.

Wasn't there also a paper by Roger Rabbit? :whistle:

WayneFrancis
2012-Jul-09, 06:51 AM
Did you look at the link to the paper I provided? It does, after all, have 96 other papers that you can look up.

Bah, Blandford is only listed 18th and that doesn't reference Penrose at all! I don't care that its in alphabetic order!

SRH
2012-Jul-09, 11:04 AM
Did you look at the link to the paper I provided? It does, after all, have 96 other papers that you can look up.

yes i did...thank you.

ngc3314
2012-Jul-09, 12:06 PM
Observational diagnostics seem to be very scarce - there are papers discussing jets with the flux dominated by protons and electrons, electrons and positrons, and either mix with local magnetic field structure carrying most of the energy density (Poynting-flux dominated, in the jargon). Begelman and colleagues have argued that electrons/positrons are unlikely to dominate the energy flux when any significant proton component is present, and that the Poynting flux drops so rapidly with distance from the jet base that it dominates the energy flow at most in the innermost regions. Indeed, conditions may change a lot from the jet launching region, maybe hundreds of Schwarzschld radii out, and the outer parts tens of kiloparsecs distant (where in some cases there is evidence for reacceleration of particles locally, further changing the energy balance).

It's getting slightly old, but here (http://adsabs.harvard.edu/cgi-bin/nph-abs_connect?bibcode=1996ASPC..100&db_key=ALL&sort= BIBCODE&nr_to_return=500&data_and=YE) are links to presentation papers at a meeting on energy transport in jets and radio lobes, where this was one of the major topics, and the basics of the problem remain the same

SRH
2012-Jul-30, 11:59 PM
Is there any known scientific evidence that would match up with the element Uranium shooting out of relativistic jets? Thanks.

ctcoker
2012-Jul-31, 02:00 AM
Not that I know of. It's almost certainly present in AGN with high enough metallicity, but the spectral signature would be so weak as to be undetectable at their great distances. AFAIK, uranium is even difficult to detect in the Sun.

SRH
2012-Jul-31, 02:37 AM
Why does uranium have a weak spectral signature?
Is it because it doesnt emit many spectral lines... because it absorbs most light?

WayneFrancis
2012-Jul-31, 03:31 AM
Why does uranium have a weak spectral signature?
Is it because it doesnt emit many spectral lines... because it absorbs most light?

I would expect it is more do to the fact that there isn't much of it. Its like asking why you can't hear a baby cry in a packed stadium watching your favourite sport when you are in the parking lot.

Any light uranium absorbs will get re emitted at some point.

ctcoker
2012-Jul-31, 03:19 PM
Exactly. Uranium has tons and tons of spectral lines owing to the fact that it has 92 electrons as a neutral atom, but there simply isn't that much of it around compared to everything else. This means that its spectral signature tends to get lost in the noise.

Cougar
2012-Jul-31, 11:21 PM
Is there any known scientific evidence that would match up with the element Uranium shooting out of relativistic jets?

No way. Single particles, anti-particles, fields, and radiation about sums up the makeup of the jets. Of course, I'm no professional, so it's best to check out that link Tensor gave, which looks quite good.

quotation
2012-Aug-04, 01:04 PM
The paper Tensor provided is pretty good, and if you liked that you might also be interested in this guy, who's been studying various jets (episodic and protostellar) throughout most of his career:http://amrel.obspm.fr/~ciardi/index.html
From the homepage he provides an interesting list of other relevant work under "Publications".

quotation
2012-Aug-07, 01:49 PM
Not sure where the paper for this blurb might reside (would be nice to have more info), but I saw this today on the SLAC website:
http://www6.slac.stanford.edu/ExploringSlacScience.aspx?id=blazar
Extreme Jets Take New Shape

Jets of particles streaming from black holes in far-away galaxies operate differently than previously thought, according to recent work led by scientists at the Kavli Institute for Particle Astrophysics and Cosmology, jointly located at SLAC and Stanford University. The study, which included data from more than 20 telescopes, reveals that most of the jet's light—gamma rays, the universe's most energetic form of light—is created much farther from the black hole than expected.

Researchers previously thought that the gamma rays must be released near the black hole, close to where the matter flowing into the black hole gives up its energy in the first place. Yet the new results suggest that, like optical light, the gamma rays are emitted relatively far from the black hole. This in turn suggests that the magnetic field lines must somehow help the energy travel far from the black hole before it is released in the form of gamma rays.