Keep in mind that Yohkoh is the only spacecraft that can falsify or verify Lockheeds suggestion. If the "hot" areas were the surface as Lockheed claimed, that is where most of the photons would come from in Yohkoh images. Instead these images show a clear correlation between the arcs and the photon emissions.

I will try one last time: as the temperature increases we get iron sufficiently ionized to be seen as Fe IX but very little or no Fe XII. Further increasing the temperature the Fe IX decreases as some of it becomes Fe X. Continuing this process to even higher temperatures we eventually start seeing Fe XII while the Fe IX has become much less prevalent. The ratio of intensity of Fe XII to Fe IX is thus a temperature sensitive parameter. No continuum radiation is involved, just measures of two narrow wavelength regions centered on Fe emission lines.

This is very standard astrophysics. You seem unwilling to read and understand it and I will bow out now since I have answered the question posed three times with increasing details and varied language.

So far we are in agreement. We both seem to agree that iron plasma reaches millions of degrees in these bright areas and it begins to emit photons in very specific areas of the surface. That does not indicate that the entire surface has reached millions of degrees however.

Let's forget about the colored image for a moment. Let's first start with the original Trace image on the left. The bright areas of the surface as seen at 171A represent iron plasma at about 1 million degrees. I have no idea about the temperature of the dark regions of the surface however since they are not emitting any visible photons. If the entire surface was 1 million plus degrees, it too should be emitting FE/ IX photons plus a whole bunch of other kinds of photons as well. If that surface however was at least 1 million degrees, why isn't it causing the iron plasma to emit iron ion photons in these areas? At 1 million degrees, that surface should light up too. It is not lit up. I therefore cannot just "assume" it is 1 million+ degrees like the base of the arc.

Yohkoh represents a "cross check" of heat distribution. The reason I posted the Yohkoh/Trace overlay image is to demonstrate that Yohkoh sees no visible light in these dark regions of the surface. Again, if the dark areas are very hot, there is no evidence of it in either Trace or Yohkoh images. There is no light coming from these areas that can be seen by either spacecraft.

Before we go any further, I need to understand why you believe the dark areas of the surface on the left image have reached a million + degrees. I see no evidence of that analysis in the Trace image itself, and no evidence of that it is hot based on the Yohkoh images either. I believe we need to discuss the heat concentration patterns in the first image before we get into the various ionization states. Once we establish a heat concentration pattern relative to Yohkoh, then we can we move on and discuss the colorized image.

http://spaceflightnow.com/news/9912/17tracemoss/
Here Lockheed-Martin states that the temperatures soars from ten thousand to milliions of degrees. Lockheed even states that the surface itself is thousands of degrees, while the lit up parts are soaring to millions of degrees. The dark areas are measured in thousands of degrees, not millions of degrees. Lockheed publicly stated this for the record. Either this statement is wrong, or Lockheed's website is wrong.

Or your interpretation is wrong!

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T. Anderson

http://150.144.30.154/~gurman/images..._sxi_pthnb.gif

This link is to the latest x-ray images of the sun from Geos-12. You'll notice that the photons are always concentrated in the magnetic flux ropes, and the surface of the sun is relatively "cool" in comparison. Whether we use Geos-12, or Yohkoh as the cross check the heat signatures of the sun follow the ropes. The surface is relatively cool.

So why do Geos and Yohkoh show the heat concentrations in the magnetic flux rope/arc? Why is the surface dark in Geos and Yohkoh images? What do the light and dark areas of Geos and Yohkoh represent in relationship to heat signatures from the surface?

You are confusing "temperature" with "heat".

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T. Anderson

I'm not sure what you mean. It takes heat (about a million degrees) to release the iron ion photons that Trace observes in 171A. It takes even more heat to emit photons from these iron streams that Yohkoh can observe. In that composite overlay between Trace and Yohkoh, you'll notice that Yohkoh only sees the base of the arcs, and very little between the base and the upper atmosphere. When the magnetic flux ropes enter the corona, they pick up heat and glows in a wavelength that Yohkoh and Geos can observe.

The temperature of the photosphere is thousands of degrees, not millions. The reason the surface is dark, is because most of the surface is measured in thousands of degrees. Only the ropes, and the base of the ropes see temperatures in the millions of degrees. We see million degree temps both by Trace and by Yohkoh, but not in the dark regions that represent thousand degree temperatures.

yes.. i see what you are saying.. these images are taken at xray wavelenghts, and so.. only spots which are emitting these xrays apear on the photo.. just like at light frequencies...

and clearly the sources of xrays are the spots and arcs..

as the xrays, being representative of the energy level of that gas, and so a measure of its tempurture...

and clearly. as these atoms leave the sun, and rise into the corona and field line area.. they seem to get hotter..

which to me suggests a reactive process with the cloud of positrons in the corona.. yielding the y and xrays that we see so clearly..
-MT

EXACTLY my dear Watson!

Well, it could just be picking up heat from the outer plasma layers. Once the loops hit the chromosphere, they pick up heat. Once they hit the corona, they REALLY pick up heat. That x-ray glow is seen higher up the rope, furthest into the higher atmospheres. The further out you go, the hotter the temperature. The photosphere surface is 6000K, the chromosphere about 6000-20000K. The corona is the likely source of heat for those xray emissions. Once the iron plasma hits the corona, it picks up huge amounts of heat.

exactly.. and why? and why y and x-rays... i say its positrons.. which serve to set up the outer field generated from the core.
and the core has a Positive charge... thus pulling all electrons in, and pushing all positrons out.

giving the whole sun a positive charge equal to the energy of a positron which is 500,000 eV and corisponds to y-rays..

but thats just my wacko theory..

The idea found in the images seems clear enough to me.. as matter floats or is projected up into these magnetic arc fields, they light up with very high energy levels..

i Don't see what there is to argue about on that matter...??
-MT

Try explaining that to Lockheed. As for your explanation for the heat and emmisions, anything seems possible at the moment. There certainly is a huge uptick in heat and photons once the iron hits the corona, that much is obvious. There is also evidence that the sun kicks out about every particle and subatomic particle "under the sun". Don't ever stop thinking "creatively" Mosheh. I love that about you.

Hummm.... if the suns outer layers are that hot, and consistantly that hot..
x- and Y ray hot... something must be sustaining it..
a Y rays can only be derived from few processes.. fewer of which could be happening in a diffuse outer corona cloud..
one method stands out.. positron/ electron fusion.. yileding 2 y-rays.

these positrons then would clearly be found where?? but tied up in the magnetic loops and coils of the suns force field...

it fits, and if nothing else, positrons i think are our best candidate.
-MT

It is not my job to teach you elementary thermodynamics. I suggest that you go study the subject (Hint: Google is your friend.). Or, maybe someone with more time and patience will come in and make the attempt.

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T. Anderson

I suggest that you spend some time reviewing thermodynamics (and come to an understanding of the difference between heat and temperature) and astrophysics (and pay special attention to the terms "optically thick" and "optically thin").

Mosheh,

This is the Questions and Answers section of BAUT, where you can post a question about astronomy, space exploration, or related fields, and folk will answer that question, within the framework of mainstream science.

This is not a place to continue discussion of ATM ideas; if you wish to have such discussions, please pick a thread where the ATM idea is already being discussed; if there is no such appropriate thread, please start a new one.

Please stick to mainstream science, and to answering questions from the perspective of mainstream science.

Nereid, please see this thread.

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I'm becoming confused by the confusion on this thread.
Can I just check my own understanding with some of the knowledgeable mainstream posters here?
Here's how it goes in my head:

1) The coronal gas imaged isn't behaving like a black body radiator, so reasoning from black body physics is useless.

2) In the OP, the 171Å (left) image is effectively tuned to a specific ion emission (Fe IX), which is a marker for temperatures around 1,000,000K. Dark areas in this image may therefore be either hotter or cooler than 1,000,000K - all we know is that they're at the wrong temperature to support a significant population of Fe IX.

3) The coloured (right) image introduces a second wavelength at 191Å, marking a more ionized state of iron (Fe XII) which requires higher temperatures to sustain. This is responsible for the blue colour that now covers the areas that were dark in the 171Å image. It tells us that there is hotter gas in these regions (3 to 5 million K, according to the text), which was invisible at the 171Å wavelength alone.

4) Neither wavelength involved in these images has any relevance to emissions from the much cooler underlying chromosphere and photosphere, which remain invisible in both images.

Is this an accurate summary?

Grant Hutchison

Very nicely summarized. The only change I would make is to say in item 2 "... significantly hotter or cooler ..."

Looks good to me.

__________________
Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

Several folk have already answered it, but somewhat in piece parts. I shall attempt to provide an answer, including the necessary background.

We start with the photosphere, which is opaque, is in thermal equilibrium, and has a blackbody temperature of ~6,000 K.

For simplicity, let's consider only the corona and TRACE images in the three EUV narrow wavebands.

The first thing to keep in mind is that the corona is pretty much transparent. This is partly because it's so doggone tenuous - the electron densities are no greater than ~10^9 cm^-3 (OOM only).

Second, the three 'iron' filters serve to produce images which trace temperatures within the corona.

So, we have atoms of iron, in a thin, hot plasma; what do we see as the temperature is raised (assume LTE - local thermodynamic equilibrium - for now)?

The neutral iron atom has 26 electrons. Heat a gas containing iron atoms and they will ionise - lose first one, then two, then three, ... electrons. The relative populations of each species (unionised, singly-ionised, doubly-ionised, etc) at any given temperature is determined by that temperature (there is also a small pressure factor; for our purposes we can ignore it - the corona very tenuous). This result comes straight from standard, textbook physics, and has been confirmed in thousands of lab experiments. (Perhaps another reader could supply some links?)

An ion, or atom, can become excited (its outer electron jumps to a higher energy state), by collision with electrons, with other ions, or by absorption of photons. Most excited states of most ions are highly unstable, the electron will jump back to the 'ground' state very quickly, either directly, or via a cascade, emitting photon(s) in the process. These photons have distinct wavelengths; if you take the spectrum of a hot plasma containing iron, you will see lots of emission lines, corresponding to the electronic transitions.

The TRACE iron filters were chosen so as to 'measure' the temperature of the corona; in particular, three iron ion transitions were chosen (per this TRACE webpage). The higher the ionisation of the iron, the higher the temperature must be for such an ion to exist in a thin plasma; if you don't see Fe XV lines in a plasma, for example, then the temperature of that plasma cannot be ~1.2 millionK (or higher); if you see Fe IX lines, then the temperature will be ~160k to 2000k K.

Why iron? Because the spectra of iron ions is rich, and contains many strong lines (as in, for a given abundance, the emission line is particularly intense, cet par).

Would another element do just as well? Yes, though the sensitivity with which temperature could be measured would be lower. In fact, much of the early work on determining the density and temperature profiles in the corona were done using Si lines, as observed on the ground (so EUV lines could even have been detected). However, H (and to some extent He) cannot be used. Why? Stay tuned!

Okay, yes, that's better, since there's clearly a range of temperatures over which a significant population of any given ion would exist.

Sigh. I was beginning to wonder if I was missing something ...

Grant Hutchison

First correction: it's a plasma containing iron; it's most certainly not an 'iron plasma'! How do we know? Well, SERTS gives a list of EUV emission lines detected in the corona, and from solar wind studies we know bits of the corona leave the Sun, as solar wind, and when we taste that wind, we finds it's mostly H.

You are correct, if there is no observed iron ion emission, the temperature of the plasma is not within the range (~160-4000k K) in which such ions would exist (in any appreciable number).

Finally, 'surface': we see the Sun in projection - every sightline passes through hundreds of thousands of km of corona and starts (ends?) with the photosphere (we can't see 'beneath' the photosphere, with photons, because it's opaque). This makes it complicated to determine where - in terms of height above the photosphere - any particular feature is. Finally, there's resolution - at the Sun's distance, 1 arcsec corresponds to some 700 km (approx; I'm using ~0 to 0.5 level OOMs in my posts today in this, and other 'iron Sun' threads; this means ~+/-10% to ~+/-40%), which is ~2 pixels in the full TRACE images (but only ~0.8 pixels in the web versions).[nitpick]We have no idea what they are emitting in the 'visible' part of the EM spectrum (~3800-7000Å); there is no corresponding image![/nitpick]

As above, given the fact that we're observing in projection, if there are no 171Å photons detected, all you can say is that along the sightline there are no Fe IX ions (or, rather, there are fewer than {some calculated number, determined from the CCD's sensitivity, the integration time, etc}).Yes, with the caveats noted above.Another nitpick which most definitely isn't: the images trace gas (plasma) at various temperatures (and they do so only approximately, of course); the do not trace 'heat'. If you are interested in learning about mainstream solar physics, please try to use the standard terminology.Actually, you can't say anything much about the temperature of the 'dark areas', from the Trace images alone.

But now you seem to be moving beyond the scope of your initial question - at the very least, please provide the Yohkoh image(s)! Without this, it is impossible to know - by reading this thread alone - what you are talking about.I will ask you, Michael, to try to re-phrase your question(s), in terms that do not require someone wishing to answer them to walk you through a great deal of textbook physics.

What is your question Michael?

I meant by my comment that the photons we see come directly from iron plasma. You are correct, there are many other elements in the rope and in the plasma. I would like to specifically focus on the relative abundances of elements in the ropes next, since that seems like an area we may find agreement.Well, heliosciesmology does suggest that something changes related "temperature" and or density at about 4800km below the photosphere. We also see these photons and it is at least "possible" these ropes begin below the visible photosphere.http://www.solarviews.com/browse/sun/moss8.jpg

Your nitpick is noted. This image is a TRACE/Yohkoh overlay of the dark and light areas of the surface. In both satellite images the dark areas of the surface remain dark, indicating the dark areas are cooler than the light areas.We can however overlay Yohkoh and Trace images to get an idea of relative temperatures.I'm simply trying to find some agreement here with temperatures of the magnetic flux ropes in relationship to the surface. Both the TRACE and Yohkoh images, particlarly that composite overlay show that the photons emmissions are concentrated in the ropes in each image, indicating the rope is much hotter than the surface. Do you agree with this assessment?

My question is how can Lockheed suggest that the temperature rises from thousands to millions of degrees and not acknowledge that the surface is cooler than the ropes? There is a problem here. Either the surface is thousands of degrees and ropes are millions of degrees as this article suggests, or the the color scheme on Lockheed's website is incorrect. Both cannot be true. These seem like mutually exclusive idea. I can easily understand the logic in the article I cited since the dark areas could indeed be measured in thousands of degrees, and the bright areas could indeed be a million degrees. The article makes perfect sense, but it suggest the opposite of what the website claims about the background temperature of the surface in relationship to the lit areas of iron plasma (amongst other heated plasma) in the rope.

Hmmm. Well.... The trace temperatures in the plasma, but it need not exist only in the corona if there is current involved in ionizing the iron plasma.

I think I will discuss the relative abundances of iron in relationship to other elements in the rope/arc thread.

Keep in mind that even conventional explanations of magnetic flux ropes involve the flow of current. If electricity flows through iron plasma ropes, the source of the heat may be the current flow, not the corona. Can we at least agree on that much?

Thanks.

First, the article is a popular account; to get the real skinny, you need to read the papers that Berger and De Pontieu wrote about their findings.

[nitpick]Second, it's LMSAL - Lockheed Martin Solar and Astrophysics Lab - not 'Lockheed'[/nitpick]. I expect that some will find my all-too-frequent nitpicking irritating, but in my experience, if you can't take the trouble to get these sorts of details right, chances are you'll have giant holes in your 'real' work.

Third, I couldn't find any mention of 'ropes' in that article - where did they talk about 'ropes'?

Fourth, why do they need to 'acknowledge' that there is a pretty interesting temperature gradient from photosphere, through transition region (chromosphere) to (lower) corona - it's well observed, and has been known for over a century?

Fifth, I can't see the apparent contradiction - does it involve more images? Yohkoh images??

I have no idea what this is Michael!

What is the image scale? When was it taken? Where (on the Sun) was it taken? What do the colours represent? How do the pixel brightness values relate to (detected) photons - linearly, log, something else??

Without this kind of information, all there is is a pretty picture.By 'magnetic flux ropes' do you mean 'coronal arches'?