From the University of Chicago
Satellite reveals surprising cosmic ‘weather’ at edge of solar system
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The first solar system energetic particle maps show an unexpected landmark occurring at the outer edge of the solar wind bubble surrounding the solar system. Scientists published these maps, based mostly on data collected from NASA’s Interstellar Boundary Explorer satellite, in the Oct. 15 issue of Science Express, the advance online version of the journal Science.
“Nature is full of surprises, and IBEX has been lucky to discover one of those surprises,” said Priscilla Frisch, a senior scientist in astronomy & astrophysics at the University of Chicago. “The sky maps are dominated by a giant ribbon of energetic neutral atoms extending throughout the sky in an arc that is 300 degrees long.” Energetic neutral atoms form when hot solar wind ions (charged particles) steal electrons from cool interstellar neutral atoms.
IBEX was launched Oct. 19, 2008, to produce the first all-sky maps of the heliosphere, which reaches far beyond the solar system’s most distant planets. Extending more than 100 times farther than the distance from Earth to the sun, the heliosphere marks the region of outer space subjected to the sun’s particle emissions.
The new maps show how high-speed cosmic particle streams collide and mix at the edge of the heliosphere, said Frisch, who co-authored three of a set of IBEX articles appearing in this week’s Science Express. The outgoing solar wind blows at 900,000 miles an hour, crashing into a 60,000-mile-an-hour “breeze” of incoming interstellar gas.
Revealed in the IBEX data, but not predicted in the theoretical heliosphere simulations of three different research groups, was the ribbon itself, formed where the direction of the interstellar magnetic field draping over the heliosphere is perpendicular to the viewpoint of the sun.
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  IMAGE: Priscilla Frisch, Senior Scientist in Astronomy & Astrophysics, and member of the science team, Interstellar Boundary Explorer. Collaborating with former UChicago astronomer Thomas F. Adams, she made the first spectrum… |
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Energetic protons create forces as they move through the magnetic field, and when the protons are bathed in interstellar neutrals, they produce energetic neutral atoms. “We’re still trying to understand this unexpected structure, and we believe that the interstellar magnetic forces are associated with the enhanced ENA production at the ribbon,” Frisch said.
IBEX shows that energetic neutral atoms are produced toward the north pole of the ecliptic (the plane traced by the orbit of the planets around the sun), as well as toward the heliosphere tail pointed toward the constellations of Taurus and Orion. “The particle energies change between the poles and tail, but surprisingly not in the ribbon compared to adjacent locations,” Frisch said.
IBEX is the latest in NASA’s series of low-cost, rapidly developed Small Explorers space missions. Southwest Research Institute in San Antonio, Texas, leads and developed the mission with a team of national and international partners. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the Explorers Program for NASA’s Science Mission Directorate in Washington.
Citations: N. A. Schwadron, M. Bzowski, G. B. Crew, M. Gruntman, H. Fahr, H. Fichtner, P. C. Frisch, H. O. Funsten, S. Fuselier, J. Heerikhuisen, V. Izmodenov, H. Kucharek, M. Lee, G. Livadiotis, D. J. McComas, E. Moebius, T. Moore, J. Mukherjee, N.V. Pogorelov, C. Prested, D. Reisenfeld, E. Roelof, G.P. Zank, “Comparison of Interstellar Boundary Explorer Observations with 3-D Global Heliospheric Models,” Science Express, Oct. 15, 2009.
H.O. Funsten, F. Allegrini, G.B. Crew, R. DeMajistre, P.C. Frisch, S.A. Fuselier, M. Gruntman, P. Janzen, D.J. McComas, E. Möbius, B. Randol, D.B. Reisenfeld, E.C. Roelof, N.A. Schwadron, “Structures and Spectral Variations of the Outer Heliosphere in IBEX Energetic Neutral Atom Maps,” Science Express, Oct. 15, 2009.
D.J. McComas, F. Allegrini1, P. Bochsler, M. Bzowski, E.R. Christian, G.B.Crew, R. DeMajistre, H. Fahr, H. Fichtner, P.C. Frisch, H.O. Funsten, S. A. Fuselier, G. Gloeckler, M. Gruntman, J. Heerikhuisen, V. Izmodenov, P.J anzen, P. Knappenberger, S. Krimigis, H. Kucharek, M. Lee, G. Livadiotis, S. Livi, R.J. MacDowall, D. Mitchell, E. Möbius, T. Moore, N.V. Pogorelov, D. Reisenfeld, E. Roelof, L. Saul, N.A. Schwadron, P.W. Valek, R. Vanderspek, P. Wurz, G.P. Zank, “Global Observations of the Interstellar Interaction from the Interstellar Boundary Explorer-IBEX”, Science Express, Oct. 15, 2009.
Related links:
Animation shows how energetic neutral atoms are made in the heliosheath when hot solar wind protons grab an electron from a cold interstellar gas atom. The ENAs can then easily travel back into the solar system, where some are collected by IBEX. Credit: NASA/GSFC http://www.swri.org/temp/ibexscience/DM/SP_draft1.mov
Solar Journey: The Significant of Our Galactic Environment for the Heliosphere and Earth, Priscilla C. Frisch, editor. http://www.springer.com/astronomy/practical+astronomy/book/978-1-4020-4397-0
IBEX Web page at Southwest Research Institute http://ibex.swri.edu/
NASA’s Interstellar Boundary Explorer mission http://www.nasa.gov/mission_pages/ibex/index.html
To view a video related to this research, please visit http://astro.uchicago.edu/%7Efrisch/soljourn/Hanson/AstroBioScene7Sound.mov
Here is another press release on IBEX from Boston University:
IBEX discovers that galactic magnetic fields may control the boundaries of our solar system
NASA mission reveals impact of galaxy’s magnetic fields
(Boston) – The first all-sky maps developed by NASA’s Interstellar Boundary Explorer (IBEX) spacecraft, the initial mission to examine the global interactions occurring at the edge of the solar system, suggest that the galactic magnetic fields had a far greater impact on Earth’s history than previously conceived, and the future of our planet and others may depend, in part, on how the galactic magnetic fields change with time.
“The IBEX results are truly remarkable, with emissions not resembling any of the current theories or models of this never-before-seen region,” says Dr. David J. McComas, IBEX principal investigator and assistant vice president of the Space Science and Engineering Division at Southwest Research Institute. “We expected to see small, gradual spatial variations at the interstellar boundary, some 10 billion miles away. However, IBEX is showing us a very narrow ribbon that is two to three times brighter than anything else in the sky.”
A “solar wind” of charged particles continuously travels at supersonic speeds away from the Sun in all directions. This solar wind inflates a giant bubble in interstellar space called the heliosphere — the region of space dominated by the Sun’s influence in which the Earth and other planets reside. As the solar wind travels outward, it sweeps up newly formed “pickup ions,” which arise from the ionization of neutral particles drifting in from interstellar space. IBEX measures energetic neutral atoms (ENAs) traveling at speeds of roughly half a million to two and a half million miles per hour. These ENAs are produced from the solar wind and pick-up ions in the boundary region between the heliosphere and the local interstellar medium.
The IBEX mission just completed the first global maps of these protective layers called the heliosphere through a new technique that uses neutral atoms like light to image the interactions between electrically charged and neutral atoms at the distant reaches of our Sun’s influence, far beyond the most distant planets. It is here that the solar wind, which continually emanates from the Sun at millions of miles per hour, slams into the magnetized medium of charged particles, atoms and dust that pervades the galaxy and is diverted around the system. The interaction between the solar wind and the medium of our galaxy creates a complex host of interactions, which has long fascinated scientists, and is thought to shield the majority of harmful galactic radiation that reaches Earth and fills the solar system.
“The magnetic fields of our galaxy may change the protective layers of our solar system that regulate the entry of galactic radiation, which affects Earth and poses hazards to astronauts,” says Nathan Schwadron of Boston University’s Center for Space Physics and the lead for the IBEX Science Operations Center at BU.
Each six months, the IBEX mission, which was launched on October 18, 2008, completes its global maps of the heliosphere. The first IBEX maps are strikingly different than any of the predictions, which are now forcing scientists to reconsider their basic assumptions of how the heliosphere is created.
“The most striking feature is the ribbon that appears to be controlled by the magnetic field of our galaxy,” says Schwadron.
Although scientists knew that their models would be tested by the IBEX measurements, the existence of the ribbon is “remarkable” says Geoffrey Crew, a Research Scientist at MIT and the Software Design Lead for IBEX. “It suggests that the galactic magnetic fields are much stronger and exert far greater stresses on the heliosphere than we previously believed.”
The discovery has scientists thinking carefully about how different the heliosphere could be than they expected.
“It was really surprising that the models did not generate features at all like the ribbon we observed,” says Christina Prested, a BU graduate student working on IBEX. “Understanding the ribbon in detail will require new insights into the inner workings of the interactions at the edge of our Sun’s influence in the galaxy.”
Adds Schwadron,”Any changes to our understanding of the heliosphere will also affect how we understand the astrospheres that surround other stars. The harmful radiation that leaks into the solar system from the heliosphere is present throughout the galaxy and the existence of astrospheres may be important for understanding the habitability of planets surrounding other stars.”
IBEX is the latest in NASA’s series of low-cost, rapidly developed Small Explorers space missions. Southwest Research Institute in San Antonio, Texas, leads and developed the mission with a team of national and international partners. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the Explorers Program for NASA’s Science Mission Directorate in Washington.
The Center for Space Physics at Boston University carries out a wide variety of research in space physics including: space plasma physics, magnetospheric physics, ionospheric physics, atmospheric physics, and planetary and cometary atmospheric studies.
kuhnkat (22:45:28) :
The other issue is the claim that neutrinos of 3 flavors and the right amount are measured at the earth to satisfy theory.
That neutrinos oscillate is well established. All your hand-wringing about that we do not KNOW this or that is mooted by the K2K experiment, where a man-made neutrino beam is aimed at the detector 250 km away. So we know what is produced at the source and what we measure at the detector. Let me repeat: there is no neutrino problem.
kuhnkat (22:45:28) :
The other issue is the claim that neutrinos of 3 flavors and the right amount are measured at the earth to satisfy theory.
The Sudbury detector is sensitive to and measures all three flavors and they add up to the expected electron neutrino flux that the Sun produces according to theory. One more time: there is no neutrino problem.
Dr. Leif Svalgaard wrote: “The current reverses direction every 11 years.”
Yes, but it still is an electric current, nevertheless.
Everybody is entitled to their own opinion, but they aren’t entitled to make up their own facts — there is an electric current in the helio current sheet.
I appreciate your pioneering papers from the 1970’s, but this is the 21st century.
So, “electromagnetic” is a weasel word. How so?
Dr. Svalgaard wrote: “It is just that there are no electric fields in the rest frame of a highly conducting plasma, as they are immediately shorted out.”
Any in situ satellite probe observation & measurement to confirm that statement or is it just speculation or conjecture?
As i stated above, NASA has devoted a whole series of connected resource webpages where electromagnetism is a highlighted process in the solar system:
http://stargazers.gsfc.nasa.gov/resources/sun_earth_background.htm
Apparently, you are quick to ignore points you don’t like, but nave no effective response to and you are quick to dump on NASA…when it serves your purpose. It seems rather obvious that NASA considers electromagnetism important to understanding the solar system, not just the letters NASA but the organization, its astrophysicists, and those astrophysicists that advise NASA, as well.
And as I stated before charged particles can have an electric field even when NOT in motion, but more important, as Langmuir noted when he named charged particles, “Plasma”, he did so because of its ability to self-organize in a fashion similar to living tissue, as Langmuir noted, like blood plasma.
When you have no in situ observation & measurement to support your claims and laboratory plasma physics experiments show plasma will self-organize without shorting out, and maintain charge seperation, you should temper your comments because we see researchers making comments like these:
“These images have revolutionized what we thought we knew for the past 50 years.”
Well, I stand corrected…at least some astrophysicists are willing to admit they don’t know it all…
James F. Evans (00:29:31) :
Yes, but it still is an electric current, nevertheless.
Of course it is a current, generated by the particles gyrating in the magnetic field, as all currents in plasmas in the Magnetic Universe.
So, “electromagnetic” is a weasel word. How so?
electromagnetic in physics is usually used about electromagnetic waves, i.e. light of various wave lengths. There is no ‘electromagnetic field’ for example. You can have an electric field or a magnetic field. In plasmas there is no electric field because the conductivity is so high that charge imbalances are shorted out immediately.
As i stated above, NASA has devoted a whole series of connected resource webpages where electromagnetism is a highlighted process in the solar system
From one of their webpages:
“The dynamic interaction of the plasma and magnetic field produces electrical fields and currents in the North and South polar regions.”
“These images have revolutionized what we thought we knew for the past 50 years.”
Is hype [and incorrect], as I have pointed out.
The spherical heliosphere was one of the models under consideration a decade ago [and was in fact first proposed by Leverett Davis in 1955]:
The Outer Heliosphere
Authors: Axford, W. I.; Suess, S. T.
From the Sun: Auroras Magnetic Storms, Solar Flares, Cosmic Rays, p. 143, Publication Date: 01/1998
Abstract
In explaining and describing the forces that shape the bubble of solar wind surrounding the Sun, there is a dearth of information. But observations from space are alleviating this situation. Three spacecraft moving away from the Sun-Pioneer 10 and Voyagers 1 and 2-are expected to penetrate the boundaries of the heliosphere within the next few years. All three spacecraft first passed close to Jupiter, and now their extended missions have become explorations of the outer heliosphere. The boundaries of the heliosphere are a standing “termination shock” in the solar wind surrounding the Sun and the “heliopause,” dividing the solar wind from the local interstellar medium. Uncertainties about the size and shape of these boundaries make it difficult to estimate exactly the time when the spacecraft will pass them. The termination shock may be nearly spherical or highly elongated, depending on how fast the local interstellar medium is flowing past the heliosphere. Pioneer 10, traveling downstream from the oncoming interstellar wind, may reach the termination shock first if, in fact, the shock is spherical. If the shock is elongated, having a larger dimension in the downstream direction, then Voyagers 1 and 2, traveling upstream, will encounter the shock first. Once these two spacecraft reach the termination shock, they will then pass through a region of solar wind plasma that has been heated by the shock. After a few years, they will pass the heliopause and go into the interstellar medium.
—–
We now know as observations have shown us what the situation is like. In the past we had several options open because we didn’t know which one it would be, but our ideas have not been overturned, just refined.
And you have still not provided us with a list of astrophysicists believing in the Electric Plasma Universe. Everybody I know in this field agree that we live in a Magnetic Plasma Universe.
James F. Evans (00:29:31) :
In the solar wind plasma there is no electric field. Now, the solar wind plasma blows with velocity V past the magnetic field B of the Earth, so in the frame of the Earth there will be an electric field E = – V x B. This electric field drives a current across the magnetosphere eventually giving rise to aurorae etc. This is an example of a current produced by a plasma moving in a magnetic field. The current also generates a magnetic field of its own that we can measure on the ground as a magnetic [sub]storm. Changes in that magnetic field can induce electrical currents in power lines and damage those. These electrical currents have their own magnetic field, etc, etc, etc. This chain also goes in the other direction, where the magnetic field of the Earth is the result of electric currents generated by the dynamo inside the core, by circulating conducting fluid iron moving across the magnetic field there, which originally came from the magnetic field in the solar system planetary disk, which eventually came from etc, etc, etc. All of these things hang together in a inseparable web going back to the primordial magnetic field created by who knows.
I came across this old NASA’s sketch of heliosphere
http://www.vukcevic.talktalk.net/NASAheliosphere.jpg
which clearly shows that the author believed the solar magnetic field lines as well as HCS form closed loops.
If so, it would enable existence of electro-magnetic feedback not only from planetary magnetospheres but also from the interactions with galactic currents and magnetic fields, as I have suggested some time ago in my hypothesis related to solar cycle periodicity. The hypothesis is persistently rejected on grounds that neither of the above (SMF & HCS) form a closed circuit, hence feedback is not possible.
The “ribbon,” is and should be of much interest to us in this particular epoch.
The “ribbon,” is shown to pass vertically thru the heliosphere, with high energies at between 40-60 deg. N. Imaging from the interior of the heliosphere correspond with exterior imaging.
Exterior image.
http://www.ibex.swri.edu/multimedia/img/datamap2.8-5.6.jpg
Interior.
Direct Observations of Interstellar H, He, and O by the Interstellar Boundary Explorer
…Previously, only neutral He had been observed, first by Ulysses outside 1.5 AU (8, 9) and then by IMAGE at 1 AU (10). Here, we present Interstellar Boundary Explorer (IBEX) observations of the interstellar neutral H, He, and O flow from January through April 2009. With the IBEX
sensors pointing radially outward on a spacecraft whose spin axis points Sunward (11), the LISM flow is in the IBEX-Lo sensor field of view (FOV) in the spring, when Earth (and IBEX) move into the flow, and in the fall, when Earth recedes from the flow (7) (Fig. 1A).The LISM flow dominates the IBEX-Lo all-sky maps at 15 and 110 eV with rates that exceed those of the diffuse energetic neutral atom (ENA) distributions (12–14) by up to four orders of magnitude (Fig. 1, B and C). The intense flow started with orbit 9 (mid December 2008), peaked in orbit 16 about –135o ecliptic longitude), and was seen through orbit 26 (April 2009) at 15 eV (Fig. 1B), but only through orbit 22
at 110 eV (Fig. 1C). A much narrower peak, maximized in orbit 16, showed up in the O maps for 280 eV and 600 eV (600 eV shown in Fig. 1D), with a tail extending from this peak towards higher latitude (up to about 20o) and smaller longitude (about –165o). The peak flux in all three maps arrives from slightly above the ecliptic plane. Based on the
expected interstellar bulk flow energies at 1 AU for an observer that moves into flow with Earth’s velocity, the distribution observed at 280 and 600 eV is largely interstellar O (529 eV bulk flow energy in the observer frame), the distribution seen up to 110 eV stems from interstellar He (132 eV), while the extended distribution seen into April at 15 eV is interstellar H (16 eV if radiation pressure cancels
gravitational attraction).
24 August 2009; accepted 2 October 2009
Published online 15 October 2009; 10.1126/science.1180971
Instead of just seeing this ribbon as draping over the heliosphere, I think we need to look at it’s 3 dimensional attributes and ask, what are its consequences to the planetary system and solar cycle?
Good exercise preceeding this post. Thanks guys, esp Leif for keeping us grounded.
Leif is probably the most knowledgeable of most of us on electric currents and magnetic fields and how they interact. He’s closer to this than most people give him credit for. Thanks Leif!
vukcevic (02:57:56) :
If so, it would enable existence of electro-magnetic feedback
There is no such thing. There can be an electric feedback or a magnetic feedback. However the HMF is carried by a supersonic solar wind and any changes cannot travel upstream. This has nothing to do with field lines being ‘open’ or not.
vukcevic (02:57:56) :
If so, it would enable existence of electro-magnetic feedback
for completeness, it should be noted that electromagnetic waves from the planets of course can travel upstream. Thus Jupiter shine on the Sun [be it visually or by radio waves] or the Earth for that matter is not only possible, but actually happening [we can see Jupiter]. The same can be said for any other object [stars, galaxies, cosmic microwave background] that shines upon us. But only the astrologers among us would consider that to be of relevance.
I agree with Carla (05:27:05) , it is important to have an idea of the intensity/concentration vs. time function of the events in order to make more definitive conclusion. At the moment we are in realm of pure speculation. However ENA (neutrals) are unlikely to affect solar magnetic/electric activity. If there is an influence, than it has to be due to the “abundance of charged particles” in the ‘belt’ area, possibly through feedback on the solar magnetic field and heliospheric current [vukcevic (02:57:56)]
http://www.vukcevic.talktalk.net/NASAheliosphere.jpg
vukcevic (06:20:42) :
possibly through feedback on the solar magnetic field and heliospheric current
which cannot travel upstream.
It’s a full vertical mostly N. hemisphere cut thru the whole heliosphere. Passing the solar disk at 1AU. Wondering how much it has increased in density since 2003. Motion and pressure points defining the interior as well as exterior of the heliosphere.
late
“One of the five IBEX papers appearing in Science this week, LANL’s lead contribution is “Structures and Spectral Variations of the Outer Heliosphere in IBEX Energetic Neutral Atom Maps.” In the paper, author Herbert Funsten notes “We have discovered an arc-shaped ribbon of high-pressure material that looks to be piled-up material from the Sun.”
Let us not forget that the ‘ribbon’ probably comes from the Sun and not from the galaxy of the interstellar medium.
vukcevic (06:20:42) : The image you give looks like a cell under the microscope!
Pure plasma!.
Leif Svalgaard (06:06:05) :
[vukcevic (02:57:56) :If so, it would enable existence of electro-magnetic feedback]
There is no such thing. There can be an electric feedback or a magnetic feedback.
Any feedback involving variable electric current related to a magnetic event, is therefore in essence electro-magnetic. There is a fundamental difference between two terms electro-magnetic and electromagnetic.
Perhaps you could explain what happens to all of the charged particles leaving the Sun. If heliospheric current is not closed circuit, and there is no return leg of the current, the particles, you say, do not accumulate in the newly discovered ribbon and now we know that the “bubble – called the heliosphere – which is created by the solar wind” is enclosed by the galactic MF so no escape for the ‘non-neutralised’ charged particles.
“…the ribbon seems to be full of charged particles, which seem to have been concentrated along its length – but how they got there is a mystery”
You also say that, at the edge of heliopause, solar magnetic field gets tangled up and HCS dissolves itself. That is totally unconvincing explanation.
Additionally, streams of electrons and protons move with different speeds and accelerations, which in itself creates another current within SW originating from polar regions, as it was discovered by Ulysses space probe
Leif Svalgaard (08:34:28) :
Let us not forget that the ‘ribbon’ probably comes from the Sun and not from the galaxy or the interstellar medium.
Let’s think a bit about this. The solar wind blows all the time, so material from the Sun after passage through the termination shock must be continuously removed by processes in the heliosheath. That there is a ribbon there must mean that the removal process is less efficient in the region where the ribbon is, allowing solar material to pile up. Eventually, the material must be removed anyway, perhaps after the gas has expanded and/or moved elsewhere by the flow. One can see that many possibilities exist. At the upcoming AGU meeting in San Francisco, a second map will have been made, and we can see if there has been a time evolution of the ribbon.
Latest from dr. Svalgaard:
Leif Svalgaard (08:34:28) :
“One of the five IBEX papers appearing in Science this week, LANL’s lead contribution is “Structures and Spectral Variations of the Outer Heliosphere in IBEX Energetic Neutral Atom Maps.” In the paper, author Herbert Funsten notes “We have discovered an arc-shaped ribbon of high-pressure material that looks to be piled-up material from the Sun.”
Let us not forget that the ‘ribbon’ probably comes from the Sun and not from the galaxy of the interstellar medium.
Hurray!
vukcevic (04:22:21) :
“Two ‘field aligned currents’ flowing in the same direction (in this case skirting along boundary of heliosphere, solar from within, galactic from without) will attract each other. This would allow mixing and neutralising of particles, as well as the abundance of leftover (non-neutralised) particles, but only in the areas where remaining parts of solar wind skirt the boundary, hence ribbon appearance.
This would explain :” the ribbon seems to be full of charged particles, which seem to have been concentrated along its length – but how they got there is a mystery…”
I also said: “I am inclined to believe that interaction is from the HCS, since it is a ‘ribbon shaped’, rather than due to faster polar solar wind, in which case it would be a much wider spread.”
Leif Svalgaard (08:34:21) responded:
“The current [in the HCS] is perpendicular to the magnetic field. So all the rest is moot. Perhaps clean up the sentence as it is ungrammatical to the point of not being comprehensible.”
No need to clean up anything, it is clear, ribbon’s particles come from the Sun, as I pointed out in my post quoted above. It is only particles associated with the HCS that can create ribbon shape, and further more its strength appears to vary with time (see Carla’s post [Carla (05:27:05)]
vukcevic (09:47:31) :
“Two ‘field aligned currents’ flowing in the same direction (in this case skirting along boundary of heliosphere, solar from within, galactic from without) will attract each other.
The currents are perpendicular to the magnetic field, so everything you surmise is not happening [as so much of the other stuff you peddle]. Drift currents do not attract each other. Please, can we return to science a bit.
vukcevic (09:47:31) :
It is only particles associated with the HCS that can create ribbon shape
The ribbon is aligned with the galactic field, not the HCS.
vukcevic (09:47:31) :
It is only particles associated with the HCS that can create ribbon shape
The ribbon is aligned with the galactic field, not the HCS.
“The ribbon follows a circular arc of high pressure that we believe is centered on the direction of the magnetic field of the interstellar cloud through which we are moving,” Funsten said. “This magnetic field seems to fundamentally organize the interaction region.”
—-
In the outer heliosphere, the HCS is not a thin ‘plane’, but a sequence of ‘walls’ of highly compressed solar wind, extending up to perhaps 20 degrees on either side of the equatorial plane. When hitting the shock all these walls merge. As I speculated, the ribbon might have to do with the removal process of shocked solar wind, something that very likely is ordered in the interstellar magnetic field system [tilted 45 degrees wrt to the sun’s equator], and not in the solar-equator system.
Leif Svalgaard (10:03:41) :
[vukcevic (09:47:31) :It is only particles associated with the HCS that can create ribbon shape]
“The ribbon is aligned with the galactic field, not the HCS.”
Not always. There is such thing as a field aligned current in plasma
http://upload.wikimedia.org/wikipedia/en/thumb/7/79/Magnetic_rope.png/300px-Magnetic_rope.png.
e.g. Birkeland current
http://en.wikipedia.org/wiki/Birkeland_current
“Peratt (1992) notes that “Regardless of scale, the motion of charged particles produces a self-magnetic field that can act on other collections of charged particles, internally or externally. Plasmas in relative motion are coupled via currents that they drive through each other”.
Hannes Alfvén promoted Birkeland’s ideas in a paper published on the generation of the current from the Solar Wind. One of Alfvén’s colleagues, Rolf Boström, also used field-aligned currents in a new model of auroral electrojets (1964).”
Field aligned currents are integral part of a magnetosphere, if so why not heliosphere, since there are many analogies between two. Field aligned currents are are common in solar flares.
Two such field aligned currents attract each other, allowing mixing of the particles. At heliopause solar magnetic field and galactic MF are in balance. Once particles are puled into realm of the galactic MF it is obvious they would be aligned with it. It would not be unexpected to find that two fields solar and galactic are aligned along the heliopause anyway, as two ‘common garden fridge magnets’ would.
Correction:
Leif Svalgaard (10:03:41) :………..
“The currents are perpendicular to the magnetic field…………
The ribbon is aligned with the galactic field, not the HCS.”
vukcevic (10:36:57) :
Not always. There is such thing as a field aligned current in plasma
No. Only when the plasma is under conditions where the free movement of the plasma is hindered by conditions external to the plasma that results in finite resistivity.
At heliopause solar magnetic field and galactic MF are in balance.
No, they are not. The gas pressure and the directed dynamic pressure are in balance, not the magnetic fields.
it would not be unexpected to find that two fields solar and galactic are aligned along the heliopause anyway, as two ‘common garden fridge magnets’ would.
Your standard problem with how cosmic plasmas and magnetic field interact. Their speeds exceed the local Alfven speeds so are supersonic. And observations show that the fields are at an angle of some 45 degrees. The HCS has nothing to do with the IBEX data or their interpretation.
“The Z-pinch model offers a simple explanation for the “giant ribbon” found wrapped around the heliosphere. The Z-pinch is naturally aligned with the interstellar magnetic field. Solar “wind” ions are scattered and neutralized by electrons from the Birkeland current filaments to form ENA’s coming from the Z-pinch ring, a giant ring about the solar system and orthogonal to the interstellar magnetic field.
…
Given the detail in this model we should expect, as more data comes in, that researchers may find in the ENA “ribbon,” bright spots, filamentary structures, and movement of the bright spots consistent with rotation of Birkeland current filament pairs and their possible coalescence.”
“Electric Sun Verified”
http://www.holoscience.com/news.php?article=74fgmwne
In example, Tim Thompson, an astrophysicist recently retired from the JPL, and an objector of some note to the ‘Plasma Universe’ hypothesis had this to say about ‘Electric Currents in Space’:
Tim Thompson, astrophysicist, was challenged by an interlocutor:”…somehow you’ve managed to convince yourself that electricity does not play a vital role in events in space.”
And Tim Thompson, astrophysicist, responded:”Wrong. I believe no such thing and neither does anyone else I know. Electric currents certainly do play a vital role in events in space, on every spatial scale from the smallest to the largest. They are incorporated into standard physical models of the solar system and cosmology. There are whole books and reams of papers on the topic. Electric currents do play a vital role in events in space without question.”
So, even someone who has serious disagreements with aspects of Plasma Universe ideas, acknowledges the significance of electric currents in space, not just in the solar system, but beyond into deep-space large structures.
I like Thompson’s comment: “:”Wrong. I believe no such thing and neither does anyone else I know. Electric currents certainly do play a vital role in events in space, on every spatial scale from the smallest to the largest.”
To highlight: “…and neither does anyone else I know.”
And: “Electric currents do play a vital role in events in space without question.”
It’s getting lonely for you and Eugene Parker…maybe you need a space heater…