APOD: SN 1006 Supernova Remnant (2008 Jul 04)

[iampete]

I have the same opinion on this as Case.

Even if we're wrong, what's the worst that can happen? You will have to return, or sign over to Chandra/Harvard, the millions you will make for posting your results on the APOD forum.

[henk21cm]

"And I would put you and this forum in the {non-commercial} category."
resp.
"I have the same opinion on this as Case"

Thanks for you point of view. When legal issues are on my path, i feel unpleasantly itchy.

The Chandra page said the stars were added from AAO2. You might be able to use the same data to get rid of them.
Also, there is a two color xray image on the Chandra page that might provide more insight to the xray data.

These new data have led to a new set of images.


Images: Credit to NASA/CXC/SAO

On the Chandra webpage a visual image is presented. That image shows the filament as a bright yellow line, just in the red and green colour plane. By labeling the objects in the green and red colour plane, and looking for the object containing the largest number of pixels, the filament is identified. There are over 15000 objects in the image, so it requires some number crunching power (roughly an hour) to find the object we are looking for. In this way i extracted the filament and added it to the composite image, left, bottom. The object finding algoritm is not perfect, a few stars are not removed. They are optically very close to the filament, just by coincidence, there is probably no physical interaction.

In the radio image, top right, there are some red specs visible outside the shock front. When you look in detail to these specs at the same location in the visual image, some of them are linked to objects which are larger and fluffier (more fluffy, fuzzy) than the stars. They look like distant galaxies. It is not an artefact of the processing i did on the images.

The shape of the filament is not visible in the radio image. In the X-ray image (top left) the shape of the filament can be seen. It is less sharp as the filament in visible light.

What the structure might be, well, Art Neufer suggested a smoke ring, when part of the atmosphere of the second star is blown away in the explosion. When i look in more detail to the Chandra website images, this idea might be a reasonable suggestion. What it might look like, X-ray and visible data combined and slightly rotated:



In the NASA visible image the yellow circle is seen almost 'edge on'.

I'm still working on the degree of symmetry in the radio image. That will take considerable more time, since i have to write a general function which mirrors the lower part of the image with respect to the symmetry line. The rotation part (forward and backward) is finished.

[apodman]

Neufer suggested a smoke ring ... the yellow circle is seen almost 'edge on'.

I see it and I believe.

[apodman]

i have a legal question

IA also NAL, but here's some US law from http://en.wikipedia.org/wiki/Fair_use (my italics) ...

"The fair use of a copyrighted work ... for purposes such as criticism, comment, news reporting, teaching ..., scholarship, or research ... is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include:

1. the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
2. the nature of the copyrighted work;
3. the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
4. the effect of the use upon the potential market for or value of the copyrighted work."

See also http://en.wikipedia.org/wiki/Fair_use#F ... e_Internet (a subsection of the same article).

TINLA, but I believe everything we usually do in this forum falls under the definition of fair use regardless of any conditions set by the copyright owner. Even when using material under the fair use doctrine, giving proper credit and complying with a copyright owner's policies and requests (within the bounds of common sense) is a courtesy and a good practice. Don't expect the copyright police at your door just for not dotting your i's or crossing your t's, though - if I were to see someone using my copyrighted work in a way I don't approve, I would tap them on the shoulder and ask them to "cease and desist" - http://en.wikipedia.org/wiki/Cease_and_desist - before I filed suit.

[Case]

Neufer suggested a smoke ring ... the yellow circle is seen almost 'edge on'.

I see it and I believe.

I see the close-up by Hubble, and I'm not convinced yet; nothing that looks like a loop.

[apodman]

I'm not convinced yet

Well, believing is still a little short of being convinced (the way I'm using the language today, anyway).

But I wouldn't expect to see a loop in the Hubble picture, which I interpret to be a close-up of a small section of the ribbon or loop.

And as far as a loop goes, I picture holding a floppy rubber band edge-on in front of my eyes: I see the near part of the loop as a continuous band in focus, but the far part appears here and there and obscured. I admit that "seeing" the far part of the yellow "smoke ring" requires a bit of imagination.

[Case]

but the far part appears here and there and obscured.

Exactly, so some parts of the far side should be visible. Lacking that, there may not be a far side.

[henk21cm]

Exactly, so some parts of the far side should be visible. Lacking that, there may not be a far side.

Correct. In an earlier comment i pointed out that -although not impossible- it is rather unlikely that the alignment is exactly edge on. Since this type of explosions is not uncommon, at least there must a dozen of similar structures visible, in which we can see the entire smoke ring. I have never seen such images (which is no proof that they do not exist).

Even if we 'think away' the yellow ellips in the drawing, the missing top part of the sphere is striking. At least the partial blocking of the explosion by the binary is a good working hypothesis. No scrutize it. Suppose there is no blocking. What other phenomenon may cause the disappearence of the top of the sphere?

1. A suggestion is that the explosion hits a denser area in the interstellar dust or gas. That would have led to a decelleration of the gas, and thus Bremstrahlung. That phenomenon, located at the top of the sphere, is strikingly absent in the radio image.
2. The explosion might have hit a local magnetic field. Usually interstellar magnetic fields are not local, unless there is an object in the direct vicinity. An objection to this argument is that a local magnetic field would not have blocked the path of the explosion, where the magnetic field is not as apparent as in the filament. In other words, in the composite image (bottom left) we would have seen a blue circular background with a yellow filament superimposed.

So the blocking hypothesis is still standing.

Apodman, i read some of the legal issue on the wiki pages. "Itchy". As far as i understand it, "profit making" and "profit lost by the copyright owner" is the key. Profit may be abstract, like name branding or reputation.

In the scientific and educational world it is sufficient to refer to the intellectual owner of an idea -Einsteins General Relativity- or physical owner of data -Spitzers images- and use the data for your analysis of a theory, explain a theory or build a new one. As far as i understand it, the purpose of this forum and its (APOD) accompanying website is (semi-)scientific and educational. Issue solved. Thanks for the assistance.

[starnut]

There may well be nothing left but an insignificant (and hard to find) brown dwarf
(; perhaps the Spitzer IR telescope could be used to look for such things).

I don't think so. During the red giant phase, the companion's core would be fusing helium at very high temperature, so when it lost its outer layer due to the blast wave, the exposed core should be shining very brightly and should remain that way even in the last thousand years. We need to find a bow shock somewhere inside the supernova remnant that would show the location of the speeding core plowing through the inside.

With regards to the "smoke ring", after reading the discussions here on whether the bright line is the edge-on view of the "smoke ring" or something else caused by the blast going through the red giant companion, I have given it some thought. I believe that it is more of a disk than a ring. Consider what happened when the blast front and the red giant's outer layer were blown past the red giant's core. The core's gravity would have caused the matter to curve inwards behind the core, the amount of deflection depending on the distance from the core. Even at the very high speed of the blast front, there would still be deflection of matter, and over the period of a thousand years, the deflected matter would have filled in the inside of the disk as it expanded away from the center. I noticed a slight darkening between the edges of the "ribbon" in the Hubble image, which I interpreted to be the interior of the disk. I would like to see closeups of the both ends of the bright line in the APOD image, to see if they are brighter due to the curvature of the edge of the disk.

Gary

[iampete]

. . . The core's gravity would have caused the matter to curve inwards behind the core, the amount of deflection depending on the distance from the core. Even at the very high speed of the blast front, there would still be deflection of matter, and over the period of a thousand years, the deflected matter would have filled in the inside of the disk as it expanded away from the center. . .

I'm not convinced of the permanence of the "fill in" of the inside of the disk. It seems to me that the deflected material would continue to move outwards, but at varying (but still very small) angles from radially outward (dependent on the amount of deflection). Any material that changed its radially outward path to "fill in" the inside of the disk would continue in a straight line to exit that "fill in" area as well with the passage of time. In other words, any "filling in" would be only a temporary phenomenon. I'm certain someone with a little more expertise than I could calculate the duration that the "fill in" material would take to exit.