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PraedSt
2008-Nov-20, 02:36 PM
I have no idea what this means, but I presume some of you would be interested.

Mysterious Source of High-Energy Cosmic radiation Discovered (http://www.physorg.com/news146324339.html)

Cosmic Rays From A Mysterious, Nearby Object (http://www.spacedaily.com/reports/Cosmic_Rays_From_A_Mysterious_Nearby_Object_999.ht ml)

The titles are slightly misleading. By 'nearby' they mean ~3,000 light years, and the location of the source has not been pin-pointed. Extract from the first article:


Researchers from the Advanced Thin Ionization Calorimeter (ATIC) collaboration, led by scientists at Louisiana State University, Baton Rouge, published the results in the Nov. 20 issue of the journal Nature. The new results show an unexpected surplus of cosmic ray electrons at very high energy -- 300-800 billion electron volts -- that must come from a previously unidentified source or from the annihilation of very exotic theoretical particles used to explain dark matter.

"This electron excess cannot be explained by the standard model of cosmic ray origin," said John P. Wefel, ATIC project principal investigator and a professor at Louisiana State. "There must be another source relatively near us that is producing these additional particles."

According to the research, this source would need to be within about 3,000 light years of the sun. It could be an exotic object such as a pulsar, mini-quasar, supernova remnant or an intermediate mass black hole.

"Cosmic ray electrons lose energy during their journey through the galaxy," said Jim Adams, ATIC research lead at NASA's Marshall Space Flight Center in Huntsville, Ala. "These losses increase with the energy of the electrons. At the energies measured by our instrument, these energy losses suppress the flow of particles from distant sources, which helps nearby sources stand out."

The scientists point out, however, that there are few such objects close to our solar system.

"These results may be the first indication of a very interesting object near our solar system waiting to be studied by other instruments," Wefel said.

01101001
2008-Nov-20, 03:40 PM
And BA Blog: Something powerful lurks nearby (http://blogs.discovermagazine.com/badastronomy/2008/11/19/something-powerful-lurks-nearby/):


[...] That’s pretty weird to think about.

It’s too early to speculate much about them. ATIC only detected the particles, but is not sensitive to direction. If a detector were used that could see where these cosmic rays were coming from, that would give a big clue to their origin. If they all come from one spot in space, for example, then we know it’s probably a black hole or pulsar. But if they come from everywhere, well, wouldn’t that be interesting?

PraedSt
2008-Nov-20, 04:18 PM
That BA blog article explains it much better.

So- a point source would imply an object we know about already, whereas 'coming from everywhere' might imply dark matter- right? That's very cool.

Jerry
2008-Nov-21, 04:00 AM
Whoooh Nellie!

The apparent excess is at an energy level, not a place? And the reason it has to be galactic is because we have a theory that says they can't get here from there?

That was the running hypothesis for decades, before it was more-or-less proven 'broad spectrum' CR's were not aligned with the galactic plain and therefore truly cosmic.

Now we have imaginary particles colliding in ways that release energy in ways that we cannot duplicate. These imaginary particles also require properties we cannot, or have not been able to study in the laboratory. This is not a "Mysterious Source of High-Energy Cosmic Radiation Discovered" but another rather untestable hypothesis.

The evidence is cool, the imagination of Dark Matter theories resourceful; but the science backing this claim is at best, weak. I have a LOT of trouble with extensions of theories that fail to meet expectations in many ways (such as the many futile searches for gravitational waves) parking power rays right at our own doorstep: When astronauts leave the protective confines of our own atmosphere, their brains are riddled with cosmic zapping. If this is Dark Matter colliding with Dark Matter, shouldn't we detect occasional extremely high energy events in our massive, sensitive neutrino detectors? Did I just lose another brain cell?

borman
2008-Nov-21, 05:59 AM
Preoccupied with a paradigm

Some theorists are finding the recent results exciting with respect to the possibility of Dark Matter Particles of a particular energy self destructing.

This involves accepting some a priori assumptions that form the basis of the paradigm. The outlook is from the vantage point that the particles are sourced at a particular place and lose energy as they arrive to our detectors.

A couple recent arxiv submissions on the topic within the popular paradigm:

Decaying Hidden Gauge Boson and the PAMELA and ATIC/PPB-BETS Anomalies
Abstract: http://arxiv.org/abs/0811.3357

Distinguishing Between Dark Matter and Pulsar Origins of the ATIC Electron Spectrum With Atmospheric Cherenkov Telescopes

Abstract: http://arxiv.org/abs/0811.3362

As and example of an alternative paradigm to arrive at the particular spike of energy range could be that the electrons are sourced from a variety of indefinite places, from nearby and far away pulsars for example and accepting that the distant electrons would still lose energy according to current theories, But then find a galactic accelerator that kicks them back up to the observed energy distribution. Different galaxies will have different peaks. Whether the acceleration is electromagnetic or gravitational, possibly due to the strength of the Dark Matter Effect within a galaxy, could be sorted out by comparing the masses of the effects between electrons, positrons, and protons. If it is blind to charge to mass ratios, this may implicate gravitational or gravity-like forces.

Jens
2008-Nov-21, 06:17 AM
I can't wait until somebody asks if the source might not be Planet X. :(

PraedSt
2008-Nov-21, 10:53 AM
My bad.
No worries. You've done nothing wrong. Mr Weor has. :D
Seriously, if you want to persuade us he's correct- take it to ATM- we'll only be willing to listen. But be prepared to get shouted at. :)


Whoooh Nellie!

Preoccupied with a paradigm
Ok, interesting theories here. But how about we give them a chance to locate the source, before we change all our current models? :)

ToSeek
2008-Nov-21, 02:16 PM
Posts relating to the "rings of Acloyne" hypothesis that Elitecamper is advocating have been moved here. (http://www.bautforum.com/against-mainstream/81525-rings-acloyne.html)

trinitree88
2008-Nov-21, 04:29 PM
I think the new pulsar wind model with dome and equatorial emission looks like a good candidate for the high velocity electrons. Nice job here by F. Curtis Michel :http://www.capca.ucalgary.ca/meetings/banff2005/talks/michel.pdf




pete....might be from a nearby pulsar, such as Geminga, or...see:http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVD-4RJ49K5-3T&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=fd323f3e77e88f43ecf2bee2a66c259f



see: J0108-1431 in Wiki's pulsar section...~ 200 light-years...See: http://en.wikipedia.org/wiki/Pulsar

PraedSt
2008-Nov-21, 05:02 PM
I think the new pulsar wind model with dome and equatorial emission looks like a good candidate for the high velocity electrons. Nice job here by F. Curtis Michel :http://www.capca.ucalgary.ca/meetings/banff2005/talks/michel.pdf

see: J0108-1431 in Wiki's pulsar section...~ 200 light-years...See: http://en.wikipedia.org/wiki/Pulsar
I'm finding that there could be hundreds and thousands of pulsars in our Galaxy. Is this true? All 'dim' pulsars though. Hmm.

novaderrik
2008-Nov-21, 09:49 PM
I can't wait until somebody asks if the source might not be Planet X. :(
nah.. that's just silly.
it was probably just an alien ship going into hyperspace or something mundane like that.

loglo
2008-Nov-23, 12:38 AM
I'm finding that there could be hundreds and thousands of pulsars in our Galaxy. Is this true? All 'dim' pulsars though. Hmm.

That sounds about right. From McLaughlin et al 2005 (http://arxiv.org/abs/astro-ph/0511587):-

Assuming that the total Galactic population of active radio pulsars is of order 10^5 (e.g. ref. 15), this discovery increases the current Galactic population estimates by at least several times.

"This discovery" refers to Rotating Radio Transients (RRATs) which appear to be old pulsars with long periods (>>4s) and have been linked to DINS.

borman
2008-Nov-23, 02:57 AM
Not all neutron stars are pulsars.

PraedSt
2008-Nov-23, 01:03 PM
That sounds about right. From McLaughlin et al 2005 (http://arxiv.org/abs/astro-ph/0511587):-
"This discovery" refers to Rotating Radio Transients (RRATs) which appear to be old pulsars with long periods (>>4s) and have been linked to DINS.
I'll have a look at that, thanks loglo.

Not all neutron stars are pulsars.
But most are, no? Anyway...one step at a time please! This is all a bit above my head... :)

some dumb kid
2008-Nov-23, 03:28 PM
i am confused did this just this start out of the blue or has it been happening for while and we just detected it for the first time?

Jerry
2008-Nov-24, 06:44 AM
No worries. You've done nothing wrong. Mr Weor has. :D
Seriously, if you want to persuade us he's correct- take it to ATM- we'll only be willing to listen. But be prepared to get shouted at. :)

Ok, interesting theories here. But how about we give them a chance to locate the source, before we change all our current models? :)

All we have now is an excess in a bandwidth that current theory says is too high to have traveled cosmic distances (If the rays were from outside our galaxy, they should have collided with the Cosmic Microwave Background.)

It is difficult to pin down sources, because the path of Cosmic Rays can be bent and twisted by electromagnetic fields.

PraedSt
2008-Nov-24, 11:34 AM
i am confused did this just this start out of the blue or has it been happening for while and we just detected it for the first time?
I always end up scaring you, so I'll leave this for others. :)

01101001
2008-Nov-24, 01:29 PM
i am confused did this just this start out of the blue or has it been happening for while and we just detected it for the first time?

How could we know? We just started detecting it, but can we say for sure it was happening before that?

But, most likely, odds-wise, it was happening for a long time. Now is not special except that you and I exist and that the tool was invented to detect this. It kinda makes sense that it was going on without our knowledge the day before, the week before, and 1000 years before. 10 billion years ago, I'm less confident about.

See Louisiana State University: Advanced Thin Ionization Calorimeter (ATIC) makes National News (http://atic.phys.lsu.edu/aticweb/).

I don't undersand your confusion. What is to be confused about? Are there some contradictory facts you see?

some dumb kid
2008-Nov-24, 02:36 PM
ok thanks. this whole thing is interesting, all i know about cosmic rays is that they contain protons and that they pound our planet daily. as for the object it could be a number of things, some sort of dark matter object, something mundane thats obscured by some thing else, or a cloked klingon bird of prey testing our defenses.

PraedSt
2008-Nov-24, 02:54 PM
as for the object it could be a number of things, some sort of dark matter object, something mundane that's obscured by some thing else, or a cloaked klingon bird of prey testing our defences.That's what I'm rooting for.

A.DIM
2008-Nov-25, 02:15 PM
Is there any possibility this object could be a Brown Dwarf?

some dumb kid
2008-Nov-25, 03:14 PM
Is there any possibility this object could be a Brown Dwarf?

OH NO ITS PLANET X :lol:

PraedSt
2008-Nov-26, 07:07 AM
OH NO ITS PLANET X :lol:
What's this? Humour about Planet X? I do believe BAUT therapy may be working for you SDK. :D

A.DIM
2008-Dec-02, 05:01 PM
Is there any possibility this object could be a Brown Dwarf?

Is this not a valid question?

If Radioactive Brown Dwarfs Are A New Class Of Pulsar (http://www.sciencedaily.com/releases/2007/04/070419111759.htm) where "It looks like brown dwarfs are the missing step between the radio emissions we see generated at Jupiter and those we observe from pulsars" why couldn't this be explained by such a body lurking nearby?

borman
2008-Dec-05, 10:26 PM
Possibly a rogue stellar black hole is wandering within 3,000 light years.

It still needs to be confirmed that there is a specific direction or two that the rays are sourced. Also it needs to be checked if there is peculiar or proper motion associated with the source(s). Also, if a rogue black hole, whether the particles derive from a jet, as in a microquasar, or whether nearby cosmic rays that pass by its gravity well that already have hyperbolic velocity get a Delta V assist from a flyby anomaly to stand out from background levels.

Once a potential location is plotted, then astronomers can try to confirm a nearby rogue black hole by looking for independent clues such as microlensing and Shapiro time delays if it is close enough to show proper motion.

While I do not find this scenario very probable, I can't rule it out either.

Van Rijn
2008-Dec-05, 11:14 PM
If Radioactive Brown Dwarfs Are A New Class Of Pulsar (http://www.sciencedaily.com/releases/2007/04/070419111759.htm) where "It looks like brown dwarfs are the missing step between the radio emissions we see generated at Jupiter and those we observe from pulsars" why couldn't this be explained by such a body lurking nearby?

How do you get from radio emissions to very high energy electrons?

A.DIM
2008-Dec-10, 02:00 PM
How do you get from radio emissions to very high energy electrons?

:eh:

I thought some radio emissions are caused by high energy electrons?

Van Rijn
2008-Dec-11, 12:51 AM
Not an answer to my question.

A.DIM
2008-Dec-11, 02:56 PM
Then please reword it; as it is I don't understand the question.

Van Rijn
2008-Dec-11, 07:13 PM
The ATIC finding was an excess of extremely high energy electrons. You mentioned an article about brown dwarfs that does not discuss generation of such electrons. Rather, it discusses radio emissions much like those of, for instance, Jupiter. So, again: How do you get from radio emissions to very high energy electrons? What's the mechanism, for a brown dwarf, and where are your references for that mechanism?

A.DIM
2008-Dec-11, 09:19 PM
"In recent years it has been discovered that these brown dwarfs can be extremely bright sources of radio emission. Up to now it has been unclear how these failed stars can produce such high levels of this nature of radiation. Initially, it was assumed that it was the same kind of radio emission as that detected from stars such as our Sun. For such stars, the radio emission is produced by high energy electrons in the star's corona which are trapped spiralling in the star's magnetic field.

However, our recent observations conducted with the Very Large Array radio telescope in New Mexico, together with optical telescopes at the US Naval Observatory and Vatican Observatory, have shown that this model is incorrect. We have detected extremely bright periodic pulses of radiation from a number of these objects which cannot be explained by the conventional processes associated with stellar radio emission. During these pulses, these supposedly failed stars are tens of thousands of times brighter than our Sun at radio frequencies! Instead a much more exotic process is required to explain such bright radio emission.

It turns out that the answer to this mystery is not to be found in the study of the radio emission from the stars but instead from the planets in our Solar System. All the magnetized planets, including Earth, are observed to emit extremely bright radio emission from their magnetic polar regions. Indeed, Jupiter can produce radio emission at low frequencies brighter than that detected from the Sun. This radiation is not produced by the same mechanism responsible for stellar radio emission but rather by a coherent process, the electron cyclotron maser, that can amplify the radiation to extremely high levels."

Is this what you're looking for?

Source (http://astro.nuigalway.ie/research/clustersvariability.html).


I'm asking a question, VanRijn, and you answered with a question.
As I understand it, BD's radio emissions are, or can be, these very high energy electrons.


So, again, is there anyone else who thinks this "mysterious source" could be a BD?

Van Rijn
2008-Dec-11, 09:31 PM
Is this what you're looking for?


No. That is about radio emissions. not the generation of extremely high energy electrons as were detected.

A.DIM
2008-Dec-11, 09:52 PM
No. That is about radio emissions. not the generation of extremely high energy electrons as were detected.

These radio emissions are the high energy electrons.
The electron cyclotron maser mechanism is what is thought to cause BDs to emit such radio waves, no?


Is there anyone else reading this that might clarify either VanRijn's question or my answer?

What am I missing?

Van Rijn
2008-Dec-11, 10:03 PM
These radio emissions are the high energy electrons.


No. Radio is EM radiation. Electrons are charged particles. They are not EM radiation.



Is there anyone else reading this that might clarify either VanRijn's question or my answer?

What am I missing?

(1)The ATIC finding was an excess of extremely high energy electrons (or positrons).

(2) You haven't presented a reference that indicates brown dwarfs generate these extremely high energy electrons.

Jerry
2008-Dec-12, 12:44 AM
If I am reading the articles correctly, the ONLY evidence that the source is local is an unquestioning assumption that the majority of the 'Cosmic Microwave Background' is cosmic. The reasoning is thus: We know the cross section of the background and, based upon local physics, we know particles at these high energies cannot travel through space without colliding with 'CMB' background photons.

It has been established for some time that the source of cosmic rays is not known 'hot spots' within our own galaxy: If they were, the distribution of cosmic rays should somewhat mirror the distribution of matter, or at least star forming areas within the Milky Way galaxy; and that is not what we observe. Therefore they must be cosmic. But if cosmic rays are truly cosmic, both cosmic rays and the cosmic microwave background (CMB) cannot exist, unless the early measurements were in error and the cosmic ray energy spectrum does not extend beyond the GKZ cutoff.

The question that remained was whether cosmic rays truly exceed the GKZ cutoff; and this probe has apparently confirmed that they do. Since they 'can't' be cosmic, and they are not aligned with galactic features, these researchers are concluding that they are produced by dark matter collisions.

There are major problems with this reasoning: Why would dark matter collisions produce cosmic rays, but not multi-spectrum rays? How does dark matter, with no detectable baryon properties, convert dark matter into baryonic matter? What current, testable laws of physics does one invoke to reach these conclusions? If a new law is needed, why is only colliding dark matter an acceptable solution? It wouldn't require new physics to conclude there is a local source of the cosmic microwave background, it would only require a mechanism that is relatively local and in some way tied to the solar orbital plane (an observed feature in the "CMB").

The CMB has three features that were not expected/predicted: Anisotrophy, measurable three sigm 'hot' and 'cold' spots, and a dipole that aligns with the solar system. The CMB lacks the polarization predicted by inflation theory. More than one reasonable hypothesis can be drawn from these observational facts, including the hypothesis that most of the CMB may not be cosmic at all.

trinitree88
2008-Dec-12, 07:41 PM
Jerry. Minor nitpick....positrons/electrons are not technically baryonic matter, as they are not baryons. The lightest baryon is the proton. Electrons/positrons are leptons..."light ones" with the muon and tau being the heavier members. Baryons consist of three quarks...leptons have none. Baryons must conserve baryon number in their decays,and have lepton number 0. Leptons conserve lepton number in their decays, have baryon number 0.
Lots of the dark matter popular writers address this lightly. There remains at present no experimental evidence that a normal hydrogen atom has appeared with a newly minted electron and a corroborating proton out of thin air....or contemporary cosmological vacuum. To do so, the Holy Grail of contemporary cosmology, would be the penultimate vindication of Fred Hoyle's original attack on the Big Bang....the generation of matter in a Steady State synthesis, from "empty space", itself. :wall: If that isn't irony, I don't know what is. :eek::doh: pete

A.DIM
2008-Dec-19, 01:37 PM
No. Radio is EM radiation. Electrons are charged particles. They are not EM radiation.

I guess I need to do some reading because as I understand it, electrons are negatively charged particles and when accelerated they emit EM radiation.



(1)The ATIC finding was an excess of extremely high energy electrons (or positrons).

(2) You haven't presented a reference that indicates brown dwarfs generate these extremely high energy electrons.

1. Right, and what might be the source is the question.

2. Van Rijn, the spacedaily article in the OP states one of "The least exotic possibilities...(could be) a nearby pulsar" while the article I linked in #24 discusses BDs as a new class of pulsar. I'm unsure why you feel I needed to provide any more reference in order to ask what seems to be an obvious question.

Regarding BDs as pulsars:

"As yet, the processes controlling the radio flashes from TVLM 513 are still unclear. There is no evidence of a binary system, so interaction of the magnetosphere with a stellar wind from a nearby star seems an unlikely cause, nor is there any sign of an orbiting planet that could produce a scenario like that of Jupiter and Io. However, rapid rotation is also thought to be a source of electron acceleration for a component of Jupiter's maser emission and this may also be the main source of TVLM 513's radio flashes."

spaceref (http://www.spaceref.com/news/viewpr.html?pid=22410)


So could a rapidly rotating nearby BD be the cause of these accelerated electrons?
Although, if there were a nearby BD it could just as well be the interaction of its magnetosphere with our sun's stellar wind, no?

I don't know which is why I ask...

But what do you think it might be, Van Rijn?
Dark Matter? A Black Hole?

Or, would you agree with Jerry and or pete that the CMB is not so "cosmic" and perhaps matter (these high energy electrons) is being generated nearby in emtpy space?

(that, if I'm understanding their discussion)

Van Rijn
2008-Dec-20, 01:51 AM
So could a rapidly rotating nearby BD be the cause of these accelerated electrons?


There is no indication that a brown dwarf would produce such extremely high energy electrons.



But what do you think it might be, Van Rijn?
Dark Matter? A Black Hole?


It would have to be from something that could produce extremely high energy electrons. That might be a black hole, neutron star, maybe dark matter.

bmpbmp
2008-Dec-20, 07:38 PM
As exciting as this sounds and I may not be the best to comment on this due to my lack of knowledge in astronomy, but concidering no one knows what this is shouldn't it be cause for concern or am I missing something here.

Thanks

timb
2008-Dec-20, 10:09 PM
Preoccupied with a paradigm

Some theorists are finding the recent results exciting with respect to the possibility of Dark Matter Particles of a particular energy self destructing.

This involves accepting some a priori assumptions that form the basis of the paradigm. The outlook is from the vantage point that the particles are sourced at a particular place and lose energy as they arrive to our detectors.

A couple recent arxiv submissions on the topic within the popular paradigm:

Decaying Hidden Gauge Boson and the PAMELA and ATIC/PPB-BETS Anomalies
Abstract: http://arxiv.org/abs/0811.3357

Distinguishing Between Dark Matter and Pulsar Origins of the ATIC Electron Spectrum With Atmospheric Cherenkov Telescopes

Abstract: http://arxiv.org/abs/0811.3362


OTOH Cosmic-ray electron signatures of dark matter (http://arxiv.org/abs/0812.1174) says the spectral shape of the electron excess is insufficient to discriminate a dark-matter origin from more conventional astrophysical explanations. The Case for a 700+ GeV WIMP: Cosmic Ray Spectra from ATIC and PAMELA (http://arxiv.org/abs/0811.3641) says look for the gamma ray smoking gun.

None of the papers appears to have evidence to distinguish dark matter annihilation from alternatives, but counting papers shows that dark matter is by far the favorite explanation at the moment. :)

01101001
2008-Dec-21, 12:30 AM
[...] shouldn't it be cause for concern or am I missing something here.

You're missing something. Be concerned about things that can harm you.

bmpbmp
2008-Dec-21, 01:52 AM
What i meant by concern is the source of this.

Jens
2008-Dec-21, 02:47 AM
What i meant by concern is the source of this.

No, there is no need to be concerned. Being concerned about getting hit by a car makes a lot of sense. But a source of gamma rays? Just for fun, suppose we discover it's a black hole that's going to devour our solar system. Do you think there's any way to deflect a black hole? It's best not to lose sleep worrying about things that are outside of our control.

bmpbmp
2008-Dec-21, 03:06 AM
But if it is a black hole wouldn't we see part of the solar system be destroyed also at 3000 light-years away that is pretty far no

Van Rijn
2008-Dec-21, 03:28 AM
Just for fun, suppose we discover it's a black hole that's going to devour our solar system.


That's probably not the best way to reassure bmpbmp. Let's be clear on this: We have not discovered a black hole that's going to devour our solar system.

01101001
2008-Dec-21, 04:22 AM
Bmpbmp, how many times have you asked the BAUT assemblage if you should be concerned by some latest cool discovery?

How many time was the answer yes?

Have you detected a pattern?

bmpbmp
2008-Dec-21, 08:24 PM
So this being a black hole is a possibility then

Cougar
2008-Dec-21, 09:11 PM
The CMB has three features that were not expected/predicted: Anisotrophy, measurable three sigm 'hot' and 'cold' spots...

Which is attributable to what? You're not the only one who would like to know.


...a dipole that aligns with the solar system....

Screening out known contaminants is a tricky business.


The CMB lacks the polarization predicted by inflation theory.

That's funny - I heard just the opposite... :think:


More than one reasonable hypothesis can be drawn from these observational facts, including the hypothesis that most of the CMB may not be cosmic at all.

Hypothesize away. Be sure to indicate why the data necessitate your hypothesis. ;)

Jens
2008-Dec-22, 01:34 AM
So this being a black hole is a possibility then

No, I'm sorry I even said that, as Van Rijn already admonished me. I didn't mean to make any suggestion about what it might be, just that there's no point worrying about such things. I could have said, what if it's a Romulan starship? I just meant to say that if you spend your time worrying about whether each new discovery means the end of the universe is coming, you will make yourself sick.

Jerry
2008-Dec-22, 05:22 AM
Jerry. Minor nitpick....positrons/electrons are not technically baryonic matter, as they are not baryons. The lightest baryon is the proton. Electrons/positrons are leptons..."light ones" with the muon and tau being the heavier members. Baryons consist of three quarks...leptons have none. Baryons must conserve baryon number in their decays,and have lepton number 0. Leptons conserve lepton number in their decays, have baryon number 0.
It is my understanding that cosmic rays above the GKZ cutoff have energy densities equivalent to baryons; that is, much heavier than leptons. (yes/no?)

Jerry
2008-Dec-22, 05:58 AM
The CMB has three features that were not expected/predicted: Anisotrophy, measurable three sigm 'hot' and 'cold' spots...

Which is attributable to what? You're not the only one who would like to know.
The primary evidence that the CMB was primal was the uniform temperature. Evidence that it is less than uniform is contraindicative of the BB thesis. Since these variations are very small, they do not kill the theory, but they do invite alternative explanations.





...a dipole that aligns with the solar system....

Screening out known contaminants is a tricky business.
...and assumptive: We just learned that magnetic reconnection events involves energy densities that are a full magnitude greater than predicted or expected. We learned in 1996 comets emit Xrays. Jupiter is a major source of microwaves; they were used to calibrate the WMAP probe, but nobody really knows why Jupiter is such a strong emitter. Saturn has almost global auroras, also a stunning surprise. The alignment of the oddball features in the CMB with the Zodiac is at least a strong caution flag: What else is going on out there?





The CMB lacks the polarization predicted by inflation theory.

That's funny - I heard just the opposite...

The measured polarization is two magnitudes less than prior inflationary predictions; and in any case, there are known calibration weaknesses in both the WMAP and COBE probes. (WMAP relied upon COBE measurements to calibrate the primary antenna, COBE lacked a stable clock.) It will be interesting to see how the PLANCK background mapping compares with these earlier studies. If the calibration is independant of the earlier measurements, I don't think Planck will find the same signature.

Jerry
2008-Dec-22, 08:37 PM
http://arxiv.org/abs/0812.3795v1


Our results indicate that the reported common asymmetric axis extending over a large range in scales is highly unlikely to be a statistical fluke. Foregrounds and systematic effects do not seem to be probable explanations. The CMB does seem to have an uneven power distribution on the sky over a large range of angular scales. An important task for further research is to find a physical explanation for this asymmetry which can predict possible effects on CMB polarization to be tested in future experiments.

Foreground, in this study, would be an alignment with the galactic plane. I would argue ANY evidence of Isotropy should be regarded as evidence that the CMB as we observe it may not be BB residue, or at the least is badly contaminated. Remember, the CMB is offered as evidence of the BB exactly because it is not isotropic.

Jerry
2008-Dec-22, 08:59 PM
http://arxiv.org/abs/0807.4880v3


The possibility of explaining the positron and electron excess recently found by the PAMELA and ATIC collaborations in terms of dark matter (DM) annihilation has attracted considerable attention...If we apply our analysis technique to the MAGIC data and assume an intrinsic power-law spectrum with index 2.02 as observed for the earlier EGRET flare at lower energies where absorption is negligible, we find that the luminosity of the MAGIC flare was similar to that of the earlier EGRET flare. In fact, the MAGIC flare was ~3 times brighter. This luminosity estimate could not be obtained using the analysis adopted by the MAGIC group, since all of the data points that they started from were affected by intergalactic absorption.

...Which, if they are correct, means I=ATIC estimates of Cosmic ray energy levels are likely too high, and therefore they could travel intergalactly without attenuation by the CMB. The plot thickens...

A.DIM
2008-Dec-29, 02:48 PM
There is no indication that a brown dwarf would produce such extremely high energy electrons.
Van Rijn, I provided a couple of links to articles about TVLM 513, a brown dwarf, doing exactly that, producing high energy electrons.
The quote in #37 discusses possible causes for these accelerated electrons, these radio waves, from this brown dwarf.
A rather clear indication, no?


It would have to be from something that could produce extremely high energy electrons. That might be a black hole, neutron star, maybe dark matter.

I see.
I'm disinclined to accept dark matter as an explanation, while I'm more inclined to think a neutron star could be so near our solar system rather than a black hole. Although, I think pulsar (rotating neutron star) could be as accurate a term. Something's accelerating those electrons and pulsars are known to do this. Of course, this leads me back to a new class of "pulsar," radio active brown dwarfs like TVLM 513.
;)

A.DIM
2008-Dec-29, 02:50 PM
http://arxiv.org/abs/0807.4880v3



...Which, if they are correct, means I=ATIC estimates of Cosmic ray energy levels are likely too high, and therefore they could travel intergalactly without attenuation by the CMB. The plot thickens...


...like southern gravy...

I feel like I'm promoting a somewhat conventional explanation!

:)

timb
2008-Dec-29, 09:26 PM
I'm disinclined to accept dark matter as an explanation, while I'm more inclined to think a neutron star could be so near our solar system rather than a black hole. Although, I think pulsar (rotating neutron star) could be as accurate a term. Something's accelerating those electrons and pulsars are known to do this.


Coincidentally Dissecting Pamela (and ATIC) with Occam's Razor: existing, well-known Pulsars naturally account for the "anomalous" Cosmic-Ray Electron and Positron Data (http://arxiv.org/abs/0812.4457)


Of course, this leads me back to a new class of "pulsar," radio active brown dwarfs like TVLM 513.
;)

The popular media article you linked to said nothing about BDs producing 600+ Gev electrons and positrons.

stella_luna
2008-Dec-29, 11:02 PM
I know this is simplistic. But, suppose this is a black hole after all, are there not other black holes closer to our solar system?

Van Rijn
2008-Dec-31, 08:45 AM
Van Rijn, I provided a couple of links to articles about TVLM 513, a brown dwarf, doing exactly that, producing high energy electrons.


:doh: No. As I (http://www.bautforum.com/1386136-post30.html) already said (http://www.bautforum.com/1386243-post32.html) repeatedly, (http://www.bautforum.com/1386271-post34.html) those did not discuss the generation of the extremely high energy electrons (or positrons) that are the subject of this thread. That's why I was asking you for references to support your brown dwarf claim.

Van Rijn
2008-Dec-31, 09:22 AM
I know this is simplistic. But, suppose this is a black hole after all, are there not other black holes closer to our solar system?

Hello, new poster. Welcome to BAUT. :)

I'm not sure I'm following your question, but if this is due to black holes, they would have to be within a few thousand light years.

A.DIM
2008-Dec-31, 02:57 PM
Hi timb.


Coincidentally Dissecting Pamela (and ATIC) with Occam's Razor: existing, well-known Pulsars naturally account for the "anomalous" Cosmic-Ray Electron and Positron Data (http://arxiv.org/abs/0812.4457)

Thanks.
Curious, if these findings are so simply explained why would they publish the results as "mysterious source" where the principal makes statements like "This electron excess cannot be explained by the standard of cosmic ray origin." ??

:think:


The popular media article you linked to said nothing about BDs producing 600+ Gev electrons and positrons.

No, it did not; rather it was about BDs being pulsar like where the mechanisms for high energy electron acceleration are not fully understood.

To me it seemed a nearby pulsar, given as one explanation, lent validity to a nearby pulsar-like BD.
This is why I asked the question.

A.DIM
2008-Dec-31, 03:26 PM
:doh: No. As I (http://www.bautforum.com/1386136-post30.html) already said (http://www.bautforum.com/1386243-post32.html) repeatedly, (http://www.bautforum.com/1386271-post34.html) those did not discuss the generation of the extremely high energy electrons (or positrons) that are the subject of this thread. That's why I was asking you for references to support your brown dwarf claim.

VanRijn, I made no brown dwarf claim as you say.
I asked if a BD could be the source of these high energy electrons. I made a connection between BDs being pulsar-like and one of the given possible explanations - a nearby pulsar - for these findings.

The articles I referenced and the quotes given discuss high energy electrons, their acceleration, and what mechanisms might be the cause on the BD.

From another (http://astro.nuigalway.ie/research/ultracoolstars.html):

"A very similar process is believed to apply to brown dwarfs, albeit producing radio emission many orders of magnitude brighter than that detected from the planets. The resulting radiation, which is very strongly beamed perpendicular to the magnetic field of the brown dwarf, sweeps Earth once per rotation period of the dwarf to produce the bright pulses. However, it remains a mystery how the high energy electrons which produce the radio emission are continuously accelerated into the magnetic poles of the dwarf. What has been established is that this radio emission requires these brown dwarfs to possess very powerful, large-scale magnetic fields as strong as those detected from the most magnetically active main sequence stars."

Van Rijn
2008-Dec-31, 07:08 PM
VanRijn, I made no brown dwarf claim as you say.


So, you never posted this:





There is no indication that a brown dwarf would produce such extremely high energy electrons.Van Rijn, I provided a couple of links to articles about TVLM 513, a brown dwarf, doing exactly that, producing high energy electrons.


This was after we'd already discussed the subject, repeatedly.



The articles I referenced and the quotes given discuss high energy electrons, their acceleration, and what mechanisms might be the cause on the BD.


And still again: They do not discuss extremely high energy electrons that are the subject of the thread.

A.DIM
2008-Dec-31, 09:24 PM
So, you never posted this:
This was after we'd already discussed the subject, repeatedly.

And still again: They do not discuss extremely high energy electrons that are the subject of the thread.

Rubbish.

All 3 articles I linked discuss the NUI Centre for Astronomy's research on BDs.
The link above expounds on the other two.
The quote above, particularly the bold, using the same verbiage, should've made it clear.

"A very similar process is believed to apply to brown dwarfs, albeit producing radio emission many orders of magnitude brighter than that detected from the planets. The resulting radiation, which is very strongly beamed perpendicular to the magnetic field of the brown dwarf, sweeps Earth once per rotation period of the dwarf to produce the bright pulses. However, it remains a mystery how the high energy electrons which produce the radio emission are continuously accelerated into the magnetic poles of the dwarf."

So, high energy electrons produce radio emissions we see from BDs.

I'd say this answers a couple of your questions: how do you get from radio emissions to high energy electrons & what indication is there that BDs produce high energy electrons.
Although, the latter was more a claim than a question as you said, "there is no indication...."

I think we're finished here.

;)

Van Rijn
2009-Jan-01, 01:26 AM
Rubbish.


Then please show where they discuss brown dwarfs generating 300-800 GeV electrons (or positrons). If they don't, they aren't relevant to the subject of this thread.

Jerry
2009-Jan-01, 10:30 PM
...
"What has been established is that this radio emission requires these brown dwarfs to possess very powerful, large-scale magnetic fields as strong as those detected from the most magnetically active main sequence stars."
Interesting. Jupiter-like? I wonder if there is a correlation between size/mass and field strength.

tusenfem
2009-Jan-03, 02:12 PM
Interesting. Jupiter-like? I wonder if there is a correlation between size/mass and field strength.

Jupiter-like, pulsar-like, ....

Anywhere that electrons are accelerated electromagnetic radiation will be emitted. In the case of acceleration at the magnetic poles of planets and stars (including compact objects) the emission is in the radio frequency band. One of the methods is "linear acceleration emission" which has been proposed for radio wave emission from electrostatic double layers. Mostly, all mechanisms are dependent on magnetic field strength and rotation rate of the object as the electric field doing the acceleration is basically the vxB electric field.

One of the first ones (I think) to do this for pulsars was Don Melrose (with a time varying electric field) and is described in his excellent book (if you are a math buff that is) Instabilities in Space and Laboratory Plasmas (http://www.amazon.com/Instabilities-Space-Laboratory-Plasmas-Melrose/dp/0521379628/ref=sr_1_1?ie=UTF8&s=books&qid=1230991833&sr=8-1).

The size of the object will not have much influence, apart from maybe creating a larger generation area at the poles, but that would be dependent again on the magnetic field strength, yadayadayada ....

A.DIM
2009-Jan-13, 03:45 PM
Then please show where they discuss brown dwarfs generating 300-800 GeV electrons (or positrons). If they don't, they aren't relevant to the subject of this thread.

I disagree.
This is about the discovery of high energy electrons from an unknown nearby source. I asked if it might be a BD, citing research which shows some BDs to emit radio waves from high energy electrons, similar to pulsars and planets alike. And while the reference doesn't specify the high energy electrons as being 300-800Gev, it remains valid as a basis for my question, which was never answered.

A.DIM
2009-Jan-13, 04:01 PM
Jupiter-like, pulsar-like, ....

Anywhere that electrons are accelerated electromagnetic radiation will be emitted. In the case of acceleration at the magnetic poles of planets and stars (including compact objects) the emission is in the radio frequency band. One of the methods is "linear acceleration emission" which has been proposed for radio wave emission from electrostatic double layers. Mostly, all mechanisms are dependent on magnetic field strength and rotation rate of the object as the electric field doing the acceleration is basically the vxB electric field.

One of the first ones (I think) to do this for pulsars was Don Melrose (with a time varying electric field) and is described in his excellent book (if you are a math buff that is) Instabilities in Space and Laboratory Plasmas (http://www.amazon.com/Instabilities-Space-Laboratory-Plasmas-Melrose/dp/0521379628/ref=sr_1_1?ie=UTF8&s=books&qid=1230991833&sr=8-1).

The size of the object will not have much influence, apart from maybe creating a larger generation area at the poles, but that would be dependent again on the magnetic field strength, yadayadayada ....

Hi tusenfem.

In your opinion, is it possible for this "mysterious" source to be a nearby BD, considering some have been found to be pulsar-like? And am I wrong thinking that were this the case, it'd have to be spinning fast to generate ~600+Gev electrons?

Thanks.

tusenfem
2009-Jan-14, 10:01 AM
A.DIM

I am not familiar with brown dwarfs, so I do not know the magnetic field strengths that they might achieve, but definitely not as strong as e.g. pulsars. So, let's see what we can try to figure out:

Here is a Nature paper (http://www.nature.com/nature/journal/v410/n6826/full/410338a0.html) on brown dwarfs and X-ray emission. A quote from that paper:



Brown dwarfs older than approx10 Myr are expected to possess short-lived magnetic fields2 and to emit radio and X-rays only very weakly from their coronae.


So I guess this sort of throws my idea into the waste basket.

A.DIM
2009-Jan-19, 02:59 PM
A.DIM

I am not familiar with brown dwarfs, so I do not know the magnetic field strengths that they might achieve, but definitely not as strong as e.g. pulsars. So, let's see what we can try to figure out:
Here is a Nature paper (http://www.nature.com/nature/journal/v410/n6826/full/410338a0.html) on brown dwarfs and X-ray emission. A quote from that paper:

Originally Posted by Berger et al.
Brown dwarfs older than approx10 Myr are expected to possess short-lived magnetic fields2 and to emit radio and X-rays only very weakly from their coronae.

So I guess this sort of throws my idea into the waste basket.

You think so?
Considering how we don't fully understand these pulsar-like BDs I wouldn't throw out your idea based on their expectations.

A more recent paper, here (http://74.125.95.132/search?q=cache:pKQmjMon9vIJ:www.arm.ac.uk/preprints/2007/498.pdf+Brown+Dwarf+radio&hl=en&ct=clnk&cd=17&gl=us), discusses BDs as well as UCDs (ultra cool dwarfs) and their sporadic long term variability, favoring ecmaser emissions as the more likely mechanism. However, and as the authors say, much more data is needed before anything which regards their emission mechanism or long term variablility is certain.

What's your take on this "quiescent" aspect of BDs / UCDs and might it affect your idea?

tusenfem
2009-Jan-19, 06:04 PM
The problem is that that paper is discussing radio emission, which is much easier to generate than X-rays, a lot less energetic.

X-ray ~1017 Hz
Radio ~107 Hz

The electron-cyclotron maser has difficulties, if I am not mistaken, when the emitted frequency gets too high. First of all the frequency is magnetic field dependent:
f = q B / 2 pi m, so zou need a heck of a magnetic field to get to X-ray, about 106 Tesla, although you can win a bit with synchrotron-self-compton radiation, where the emitted photons are inverse-compton scattered at the energetic electrons that are creating the photons.

A pulsar has ~1012 gauss magnetic field at the pole (1 Gauss = 10-4 Tesla) and a radius of 12 km
A brown dwarf has a radius of Jupiter (~71000 km)
Conservation of magnetic flux then gives a dipole field of about (12-71000)2 = 3 10-8 smaller, waaaayyyyy below the needed value.



However, my gut feeling tells me that

A.DIM
2009-Jan-21, 01:38 PM
The problem is that that paper is discussing radio emission, which is much easier to generate than X-rays, a lot less energetic.

X-ray ~1017 Hz
Radio ~107 Hz

The electron-cyclotron maser has difficulties, if I am not mistaken, when the emitted frequency gets too high. First of all the frequency is magnetic field dependent:
f = q B / 2 pi m, so zou need a heck of a magnetic field to get to X-ray, about 106 Tesla, although you can win a bit with synchrotron-self-compton radiation, where the emitted photons are inverse-compton scattered at the energetic electrons that are creating the photons.

A pulsar has ~1012 gauss magnetic field at the pole (1 Gauss = 10-4 Tesla) and a radius of 12 km
A brown dwarf has a radius of Jupiter (~71000 km)
Conservation of magnetic flux then gives a dipole field of about (12-71000)2 = 3 10-8 smaller, waaaayyyyy below the needed value.

However, my gut feeling tells me that

Is there something more you were going to say?

tusenfem
2009-Jan-22, 08:43 AM
I guess there was

mgmirkin
2009-Feb-04, 12:52 AM
The ATIC finding was an excess of extremely high energy electrons.

Don't know whether this is related specifically, though I think it *may* be? Assuming we're talking about excess / anomalous energetic electrons... Apologies if this paper has been mentioned already. Haven't had time to peruse the 4 pages of the thread yet.

(Heliosheath Synchrotron Radiation As A Possible Source For The Arcade 2 CMB Distortions)
http://xxx.lanl.gov/abs/0902.0181
http://xxx.lanl.gov/ftp/arxiv/papers/0902/0902.0181.pdf


This brief note speculates that the recently reported residual CMB signal [Seiffert et al 2009] may originate within the Sun’s heliosheath. A temperature spectrum function is derived that has the same power law form as the fitted function in Seiffert et al. In particular a spectral index of +2 is implied. An optically thin radiating shell of thickness ~ 1AU could match the required 1K deg power law amplitude. A possible mechanism for the heliosheath magnetic fields is discussed based on Alfven’s heliospheric current model with embedded double layers as the energy source for the relativistic electrons.

If it's not directly related to the original thread's topical article(s), is it at least potentially applicable to the same issue?

Is it possible that our solar system (or rather the heliospheric boundary / heliosheath) *is* the source of some of the cosmic rays being detected by ATIC and/or Arcade 2 as suggested (lightly) by Sharpe?

Anyway, thought folks would find the article of interest re: the current topic. Discuss amongst yourselves.

Regards,
Michael

mgmirkin
2009-Feb-04, 02:01 AM
However, it remains a mystery how the high energy electrons which produce the radio emission are continuously accelerated into the magnetic poles of the dwarf.

Just a brief thought. Hultqvist might have a *possible* / tentative explanation, derived from known / newly measured terrestrial auroral physics.

(On the importance of auroral processes in the Universe.)
http://dx.doi.org/10.1016/j.jastp.2008.03.023

Unfortunately, it requires like $30-35 to download. I wish science were actually available to John Q Public rather than sequestered in ivory towers, but c'est la vie, non?


Acceleration of charged particles in magnetic field-aligned electric potential differences at Earth and at the outer planets in the solar system is summarized and its general importance in the Universe is briefly discussed.

The role of field-aligned currents, driven by parallel electric fields, in causing filamentary structure in stellar atmospheres is briefly reviewed.

The differences between auroral optical emissions at various planets are summarized.

The important role of field-aligned potential differences in the generation of AKR and corresponding emissions from other objects is discussed.

Finally, aurora-associated processes for ejection of planetary plasma into space are briefly reviewed.

It's an interesting article, if you've got access. Tentative, but interesting. Notes that the electron-cyclotron maser instability may give us a window into how auroras and other processes in the universe operate, since many seem to produce radio emissions similar to if not the same as that produced by the aforementioned plasma process.

See also:

(Sporadic Long-term Variability in Radio Activity from a Brown Dwarf)
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.0634v1.pdf


... We discuss this large variability in the radio emission within the context of both gyrosynchrotron emission and the electron-cyclotron maser, favoring the latter mechanism.

and

(Confirmation of the Electron Cyclotron Maser Instability as the Dominant Source of Radio Emission from Very Low Mass Stars and Brown Dwarfs)
http://adsabs.harvard.edu/abs/2008arXiv0805.4010H


We report on radio observations of the M8.5 dwarf LSR J1835+3259 and the L3.5 dwarf 2MASS J00361617+1821104, which provide the strongest evidence to date that the electron cyclotron maser instability is the dominant mechanism producing radio emission in the magnetospheres of ultracool dwarfs ...

Regards,
~Michael

tusenfem
2009-Feb-04, 08:56 AM
I just asked a colleague to download the Hultqvist paper. Seems interesting and just in my street of work.

ETA: I now have said Hultqvist paper in pdf.

mgmirkin
2009-Feb-05, 12:50 AM
I just asked a colleague to download the Hultqvist paper. Seems interesting and just in my street of work.

ETA: I now have said Hultqvist paper in pdf.

Yeah, I had a brief skim of it from a colleague as well. Seemed pretty good. I'm probably not qualified to assess the specific technical merits at this point (though I followed portions of it well enough), but I assume others in the forum should be able to pick it apart for technical plausibility and usefulness under other circumstances.

From what I can gather, Hultqvist seems to follow the Alfvén line of reasoning and investigation RE: the auroras. Not sure whether he's in any way a protége or studied under Alfvén, or is simply familiar with the work.

Either way he seems to have plenty of kind words for Alfvén in acknowledging that Alfvén made a lot of predictions and suggestions that weren't taken seriously at the time or were dismissed but later confirmed. *Shrug* Alfvén had a fair enough track record.

Regards,
~Michael

tusenfem
2009-Feb-05, 08:27 AM
I have not read the paper yet, too busy writing my own paper at the moment, but will do it this weekend or this evening after the gym.

Well, you cannot be a Swedish space physicist and NOT be influenced by Alfvén (mm bet you can't be a plasma physicist in general and not be influenced by him). What Hultqvist is describing is basically the mainstream view of aurora's, when I look at it quickly, field aligned (Birkeland) currents, parallel electric fields, inverted V's etc.

Alfvén was a great plasma physicist, unfortunately at the end of his life he started moving into some strange stuff, like his "resonance theory" in the Saturnian rings (he even wanted me to start working on that when I was in Stockholm, but my PhD experiments were on double layers, so his "request" was a bit off topic). So, let's just remember him as the guy who created MHD, double layers and some other interesting stuff.

A.DIM
2009-Feb-05, 09:21 PM
I'd like to read the paper by Hallinan et al which confirms the ec maser mechanism.
The final statement in the abstract intrigues me: "The implied size of the radius, together with the bolometric luminosity of the dwarf, suggests that either LSR J1835 is a young- or intermediate-age brown dwarf, or that current theoretical models underestimate the radii of ultracool dwarfs."

Tusenfem, if the above is the case would it account for the problem you mentioned in #71?

timb
2009-Mar-03, 08:48 PM
OTOH Cosmic-ray electron signatures of dark matter (http://arxiv.org/abs/0812.1174) says the spectral shape of the electron excess is insufficient to discriminate a dark-matter origin from more conventional astrophysical explanations. The Case for a 700+ GeV WIMP: Cosmic Ray Spectra from ATIC and PAMELA (http://arxiv.org/abs/0811.3641) says look for the gamma ray smoking gun.

None of the papers appears to have evidence to distinguish dark matter annihilation from alternatives, but counting papers shows that dark matter is by far the favorite explanation at the moment. :)

Odds for dark matter being the explanation lengthening considerably. Dark Matter Signals In Cosmic Rays? (http://arxiv.org/abs/0903.0165)


The flux of the diffuse gamma-ray background radiation (GBR) does not confirm that the excess in the flux of cosmic ray electrons between 300-800 GeV, which was measured locally with the ATIC instrument in balloon flights over Antartica, is universal as expected from dark matter annihilation. Neither does the increase with energy of the fraction of positrons in the cosmic ray flux of electrons in the 10-100 GeV range that was measured by PAMELA imply a dark matter origin: It is consistent with that expected from the sum of the two major sources of Galactic cosmic rays, non relativistic spherical ejecta and highly relativistic jets from supernova explosions.

Swift
2009-Mar-05, 04:34 AM
There is a nice review article in the 28th Feb issue of Science News (on-line version here (http://www.sciencenews.org/view/feature/id/40759/title/Cosmic_mystery)).

A.DIM
2009-Mar-09, 03:17 PM
Interesting; thanks guys.

The mystery remains...

borman
2009-Aug-11, 02:43 AM
Geminga and MILAGRO observations linked to cosmic rays

Although this is an older thread, there has been some new research done on the mystery of the source of these cosmic rays.

From Physicsworld:

EXCESS POSITRONS LINKED TO GEMINGA PULSAR
http://physicsworld.com/cws/article/news/40065

Swift
2009-Aug-11, 12:57 PM
Thanks for the update borman

A.DIM
2009-Oct-16, 01:04 PM
This could've been its own thread I suppose but it might be an alternative to borman's info(?):

Mystery Emissions Spotted at Edge of Solar System (http://www.space.com/scienceastronomy/091015-space-bubble.html).

In the murky boundary between our solar system and the rest of the galaxy, scientists have spotted a bright band of surprising high-energy emissions.

Swift
2009-Oct-16, 01:27 PM
This could've been its own thread I suppose but it might be an alternative to borman's info(?):

Mystery Emissions Spotted at Edge of Solar System (http://www.space.com/scienceastronomy/091015-space-bubble.html).

In the murky boundary between our solar system and the rest of the galaxy, scientists have spotted a bright band of surprising high-energy emissions.
Also being discussed in this thread (http://www.bautforum.com/space-exploration/80075-ibex-interstellar-boundary-explorer-mission.html) on the IBEX mission that discovered it, and by Fraser on UT.

A.DIM
2009-Oct-16, 01:49 PM
Also being discussed in this thread (http://www.bautforum.com/space-exploration/80075-ibex-interstellar-boundary-explorer-mission.html) on the IBEX mission that discovered it, and by Fraser on UT.

Ah, thanks.

Good that it's cross referenced!

publiusr
2009-Oct-16, 08:24 PM
Here is a question. Let us say there was a pulsar that was orbited by a brown dwarf that was originally larger but lost a lot of gas, and that the brown dwarf was in an elliptical orbit. The Brown dwarf thus was between us and the pulsar it orbits for some time. It then nears, blows off some material which is eaten, then goes silent again.

Could such a binary system exist, explaining any sporadic spikes that might be detected, with a larger less dense body hiding a smaller, more energetic body for lengths of time?

borman
2009-Oct-19, 12:12 AM
Possibly a rogue stellar black hole is wandering within 3,000 light years.

It still needs to be confirmed that there is a specific direction or two that the rays are sourced. Also it needs to be checked if there is peculiar or proper motion associated with the source(s). Also, if a rogue black hole, whether the particles derive from a jet, as in a microquasar, or whether nearby cosmic rays that pass by its gravity well that already have hyperbolic velocity get a Delta V assist from a flyby anomaly to stand out from background levels.

Once a potential location is plotted, then astronomers can try to confirm a nearby rogue black hole by looking for independent clues such as microlensing and Shapiro time delays if it is close enough to show proper motion.

While I do not find this scenario very probable, I can't rule it out either.

IBEX measures energetic neutral atoms while the cosmic rays discussed in this thread are charged. One would not expect the two to be related as charged particles can be governed by magnetic fields whereas the neutral atoms would not.

However, IBEX sees the band at right angles to the magnetic field and there is fine structure suggesting more energetic neutral particles in the center of the band.

A speculation that might connect the two is that there is a rogue black hole and the ribbon represents its accretion disk seen edge-on by IBEX. Charged particles from the same source would suffer deflection from galactic and solar system magnetic fields. For there to be anything to this supposition, there should also be present microlensing and or Shapiro time delays associated with the gravity field of the black hole that should be monitored in the vicinity of ribbon.

publiusr
2009-Oct-19, 11:17 PM
After the finding of ring fragments around a certain ice giant, and the large ring around Saturn that was unseen previously, I wonder if Sol has a diffuse Vega style outer ring. The leading edge of such a ring fragment might 'ablate' gently in the interstellar medium, mixing with who knows what. Thus we see the linear path as a leading edge of some kind. IBEX might be blind to other parts segments of the ring that trail our system and are thus not excited by the ring and thus not as visible to it. Where the clumps are heavier, you might see an object. http://www.bautforum.com/astronomy/95040-ring-around-heliosphere.html

borman
2009-Oct-21, 03:36 AM
It can theoretically be sorted out if the ring is indigenous to the solar system or be an accretion ring centered around a mass other than the sun. If around another mass there should be a blue-shift of light that is approaching us and a red-shift from the part of the accretion ring that is moving away from us. If the ring is around the sun, no significant shifting would be expected from the sun's point of view.

Since the IBEX measures energetic neutral atoms, the main player would be gravity rather than magnetic fields. The fine structure could be a second independent example of Milgrom's predictions regarding possible solar system effects due to the EFE or external field effect. The first possible example was pointed out by Iorio with regard to the retrograde perihelion advance of Saturn. Milgrom suggested there also was a weak quadrupole effect where particles would be pushed towards a plane although it is not clear that this plane is the same as the ecliptic. The effect gets stronger as one gets away from the sun. These forces are very weak being a million times weaker than the Pioneer anomaly and a trillion times weaker than the flyby anomaly. So any magnetic field would dominate over this. But neutral atoms could manage to suffer from the force and crash into the plane after falling for a long time. The plane would be the hottest place and cooling as one gets away from the plane. This is the apparent profile of the fine structure seen by IBEX.

It does appear serendipitous that the IBEX and Saturn observations occur just on the heels of Milgrom's recent paper this past summer.

publiusr
2009-Oct-23, 10:43 PM
Indeed.

Have any detailed photographs been taken revcently towards the center of this plane? I have been wondering about DM 61 366. Same part of the sky as that star?

borman
2009-Oct-30, 02:40 AM
I am unaware of any other images than the IBEX. If the plane of neutral particles is close to the heliosphere they may make good targets just due to the density for spallation products. Could the PAMELA, ATIC, and FERMI excesses be due to cosmic rays ramming this plane of neutral particles and making the extra electrons and positrons? Would this preclude the need for Dark Matter Particle self-destruction scenarios?