Part II of Just Breathe: A Star's Death Exhales Oxygen Into Space

Dr. Patrick Slane from the Chandra X-ray Center recently shared some information on the G292.0+1.8 supernova remnant with NASA's museum alliance. Part II of this conversation talks more on what we're seeing in the Chandra image....

-------------------
So now back to picture. We've got this big explosion. This explosion flings out all of this synthesized material, these-- we refer to them as metals, but the point is that there's nuclei that are heavier than hydrogen and helium -and it flings them out into space. This explosion blast expands out into space; it starts sweeping up the material in the interstellar medium around it. By that I mean, the material between stars-- there's not a lot of material but there is material.

There's a particle per cubic centimeter or something like that. These supernova remnants are really, really big and they sweep up huge amounts of materials.

So when you look out in X-rays, what you find out is the explosion has swept up material around it to temperatures of millions of degrees. And it has heated up this material that it ejected from the center of the star. We call this the stellar ejecta -the oxygen, the neon and magnesium and all of that.

And this picture that we're looking at shows all of that. You see as you go around the picture -north is to the top; west is to the right because in astronomy images that's the way-- West is always on the right it’s not on the left as you're used to thinking of a terrestrial map.

So as you go around the remnant you see this thin, fuzzy, little hazy halo kind of around this whole thing -it's sort of reddish colored. You see a thin filamentary circle that goes most of the way around the entire supernova remnant.

And the colors in this particular image have been chosen such that red is material that's mostly dominated by oxygen and neon material. The emission from oxygen and neon -some orange is mixed in too; that corresponds to a different component of neon. Green is emission that's mostly from magnesium. And blue is emission that's mostly from silicon and sulfur.

You look around the edges, you see this sort of reddish colored stuff. And that material we know from our work, from looking at spectroscopy, that that material has the same composition as the average material in the interstellar medium.

That's where the explosion has started sweeping up the outer envelope that used to be part of the star and all of the interstellar medium that it's kind of expanding out into.

There's a bar across the center of this thing. It's kind of a white colored wavy bar that runs sort of left to right, it curves a little bit to the lower right after it gets to the center.

And that bar also curiously is made up of material that's characterized by the interstellar medium or the outer portions of the star. Not this real enriched oxygen and neon and stuff.

And we think that that material is actually indicating that this star had an equatorial sort of ring around it that when the explosion occurred it's found that higher density ring and it lit it up to be brighter.

And then all of this other really great stuff, the really colorful complex filamentary stuff in its picture, that's all ejecta, that's all oxygen, neon, some magnesium and silicon. And it's just a really beautiful graphic example of how we get these elements -or how nature gets these elements -out into space.

This particular region is in the Centaurus constellation. It's in the southern sky. It's about 59 degrees below the equator.

If you were at an optical observatory looking for this, you would be in the southern hemisphere looking some time probably in April or May, which is when it would be up.

And there's not a lot going on in the optical here (See http://chandra.harvard.edu/photo/2007/g292/g292_dssonly.jpg) The truth is it's a little unfair because if you use special filters, there are some features from this that you can see in the optical.

But basically, you can think of, this is what the sky might look like before there was an explosion. And then if you look at it in X-rays suddenly you see where the supernova remnant lies in that sky.

--------------------------------

More information at http://chandra.harvard.edu/photo/2007/g292/