Comments on: AAS #5: Tortured Veil http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/ I am an astronomer, writer, and skeptic. I likes reality the way it is, and I aims to keep it that way. My real name is Phil Plait, and I run the Bad Astronomy blog. Sun, 05 Jul 2009 03:27:10 +0000 http://wordpress.org/?v=2.3.1 By: occam's comic http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62934 occam's comic Tue, 15 Jan 2008 20:42:12 +0000 http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62934 Hey Irishman take a look at this picture of plasma filaments and you can see the similarities. http://en.wikipedia.org/wiki/Image:Plasma-filaments.jpg Hey Irishman
take a look at this picture of plasma filaments and you can see the similarities.

http://en.wikipedia.org/wiki/Image:Plasma-filaments.jpg

]]> By: Irishman http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62933 Irishman Mon, 14 Jan 2008 21:01:26 +0000 http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62933 Thanks. I emailed the press release contact, got a response that wasn't very detailed. He did comment the image was visible light, composite image of several filters, and color coded for different gases. Thanks. I emailed the press release contact, got a response that wasn’t very detailed. He did comment the image was visible light, composite image of several filters, and color coded for different gases.

]]> By: Rosa W. http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62932 Rosa W. Sat, 12 Jan 2008 01:50:18 +0000 http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62932 Actually, the light from these filaments is in fact emission from the gas - that is, the gas itself is giving off light. (These are for that reason called "emission-line" images.) The atoms in the gas are "excited" - that is, they gain energy, and electrons move up to higher energy-levels. In this case, since the Veil Nebula is part of a supernova remnant (the result of a very very large explosion of a star), the shock of the explosion is what did the original exciting of the atoms. The atoms then spontaneously de-excite; the electrons go to lower energy levels, and the atom emits energy - in the form of light - at precise wavelengths corresponding to the type of atom and the former energy level of the electron. Short version: the excited atoms give off light, which we then detect. The press release doesn't say what specific wavelengths made up this picture, but a common scheme used by supernova-remnant folks at NOAO is to use lines of hydrogen, sulfur, and oxygen as red, green, and blue. This image looks like what I'd expect from that sort of color-coding. Actually, the light from these filaments is in fact emission from the gas - that is, the gas itself is giving off light. (These are for that reason called “emission-line” images.) The atoms in the gas are “excited” - that is, they gain energy, and electrons move up to higher energy-levels. In this case, since the Veil Nebula is part of a supernova remnant (the result of a very very large explosion of a star), the shock of the explosion is what did the original exciting of the atoms.

The atoms then spontaneously de-excite; the electrons go to lower energy levels, and the atom emits energy - in the form of light - at precise wavelengths corresponding to the type of atom and the former energy level of the electron. Short version: the excited atoms give off light, which we then detect.

The press release doesn’t say what specific wavelengths made up this picture, but a common scheme used by supernova-remnant folks at NOAO is to use lines of hydrogen, sulfur, and oxygen as red, green, and blue. This image looks like what I’d expect from that sort of color-coding.

]]> By: Irishman http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62931 Irishman Fri, 11 Jan 2008 18:49:26 +0000 http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62931 I see a lot of texture in the image. I see some zones where the texture could be interpreted as spirals. However, I think they could alternately be interpreted as areas where the surface reflections and transluscencies interact, kind of like a shiny silk scarf piled up in a wrinkly clump. So I guess my question is how do you differentiate spirals from wrinkles? I see a lot of texture in the image. I see some zones where the texture could be interpreted as spirals. However, I think they could alternately be interpreted as areas where the surface reflections and transluscencies interact, kind of like a shiny silk scarf piled up in a wrinkly clump. So I guess my question is how do you differentiate spirals from wrinkles?

]]> By: occam's comic http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62930 occam's comic Thu, 10 Jan 2008 05:06:59 +0000 http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62930 Hi Irishman, If you click the link and download the largest picture and look closely at the filaments, you will see that many of them come in pairs that twist around each other. (this is a common behavior of plasma.) Responding to point 1. It is my understanding the picture was taken using visible light, I may be under the wrong impression and it may be a composite IR/ Vis, the information was not given. But that got me thinking how can we tell the difference between reflected light from nearby stars and emitted light from a plasma. If this is a plasma structure it should be glowing more strongly with UV light, I don't think that would be the case for light reflected off gas clouds. Has anybody looked at the "Veil" in UV? Hi Irishman,

If you click the link and download the largest picture and look closely at the filaments, you will see that many of them come in pairs that twist around each other. (this is a common behavior of plasma.)

Responding to point 1.
It is my understanding the picture was taken using visible light, I may be under the wrong impression and it may be a composite IR/ Vis, the information was not given.

But that got me thinking how can we tell the difference between reflected light from nearby stars and emitted light from a plasma. If this is a plasma structure it should be glowing more strongly with UV light, I don’t think that would be the case for light reflected off gas clouds. Has anybody looked at the “Veil” in UV?

]]> By: Irishman http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62929 Irishman Thu, 10 Jan 2008 01:27:42 +0000 http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62929 occam's comic said: > Show me an experiment in which gas is injected into a vacuum chamber and it forms glowing sheets, ribbons or filaments. (Or even a computer simulation of that happening) 1. The glowing is not the gas emitting visible light, but reflected light and different spectra of infrared shifted to visible colors. 2. No vacuum chamber will demonstrate this because the scale is immense - galaxy sized interactions. 3. I don't have any computer simulations, but the appearance is remisniscent of turbulence visible in water. > Why are there pairs of helical twisting filaments? What pairs of helical twisting filaments? > I think that it is pretty clear that these are charged plasma structures not a structure made of neutral gas. I think you are misinterpreting what you are seeing. occam’s comic said:
> Show me an experiment in which gas is injected into a vacuum chamber and it forms glowing sheets, ribbons or filaments. (Or even a computer simulation of that happening)

1. The glowing is not the gas emitting visible light, but reflected light and different spectra of infrared shifted to visible colors.

2. No vacuum chamber will demonstrate this because the scale is immense - galaxy sized interactions.

3. I don’t have any computer simulations, but the appearance is remisniscent of turbulence visible in water.

> Why are there pairs of helical twisting filaments?

What pairs of helical twisting filaments?

> I think that it is pretty clear that these are charged plasma structures not a structure made of neutral gas.

I think you are misinterpreting what you are seeing.

]]> By: DenverAstro http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62928 DenverAstro Thu, 10 Jan 2008 00:52:27 +0000 http://blogs.discovermagazine.com/badastronomy/2008/01/08/aas-5-tortured-veil/#comment-62928 I wish I had been keeping a better log of my observation nights so I had some idea of how many hours I have spent at my 10" Dob looking thru an Oxy3 filter at this object. In a really dark location where you have a really transparent dark sky, there are few objects prettier. Of course, I have never seen the kind of detail seen in this photo, but I have seen a lot of structure and the more you look, the more you see. What a wonderful hobby, pasttime, passion, astronomy is. Thanks for the reminder Phil :o) I wish I had been keeping a better log of my observation nights so I had some idea of how many hours I have spent at my 10″ Dob looking thru an Oxy3 filter at this object. In a really dark location where you have a really transparent dark sky, there are few objects prettier. Of course, I have never seen the kind of detail seen in this photo, but I have seen a lot of structure and the more you look, the more you see. What a wonderful hobby, pasttime, passion, astronomy is. Thanks for the reminder Phil :o)

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