M82 starburst

[MarkH]

I have just been reading up on and looking at composite images of M82. There is description about a tidal intervention from M81 causing the starburst. But to my mind the compostite looks like a supernova remnant overlayed on the galaxy image, as if it is a long way closer to us than the galaxy. Does anyone else see it like this? Or maybe it's just the way my mind works.

[Mike]

I don't see anything.

[MarkH]

Mike have a look at the composite image on wikipedia the stuff I'm talking about is all the orange coloured squigley stuff extending outwards.

[Rick]

Is this the page you're talking about: http://en.wikipedia.org/wiki/Messier_82 ?

[MarkH]

Yup that's the one Rick.

[Carole]

Had never thought of it this way before, but now you come to mention it in some ways it does make more sense than weird projections emanating in 90 degree directions from the cigar shape. 

I wonder if any-one has been able to measure this - would there be some degree of parallax if this were the case, though I guess that would depend on how far apart they actually were.  Or maybe even a previous supernova on M82 itself.

Carole

[The Thing]

I read that the dust that runs across the 'cigar' is actually in our galaxy, it is a foreground object.

[MarkS]

All the explanations I've read (including the Wiki article below) say the the (almost) symmetrical set of red H-alpha filaments spewing from the centre are due to the violent star creation region (starburst) near the centre.  If the red filaments came from within our own galaxy, it would have been pretty obvious that it was so much closer than M82.  Also an incredible coincidence that it is directly along the same line of sight.

[Rick]

The composite IR/visible/X-ray images are pretty, but it really helps to see the individual components not in composite, too. Incredible coincidences happen often enough. However, M82 has been well enough studied that if it were one of those it would be fairly easily detected (red-shifts, etc.), and it'd be a very well-known example by now.

[MarkH]

Thanks y'all seems prettey well explained.