Comments on: Galactic tentacles of DOOM http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/ 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. Wed, 25 Nov 2009 00:28:19 -0600 http://wordpress.org/?v=2.8.4 hourly 1 By: anon http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/comment-page-1/#comment-132080 anon Wed, 05 Nov 2008 23:18:04 +0000 http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/#comment-132080 I don’t see galaxies colliding, just the FSM and his noodly appendage… I don’t see galaxies colliding, just the FSM and his noodly appendage…

]]> By: Greg http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/comment-page-1/#comment-125088 Greg Sun, 12 Oct 2008 20:21:31 +0000 http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/#comment-125088 looks like sunglasses or / either a celestial bra ..virgo's bra ! lol looks like sunglasses or / either a celestial bra ..virgo’s bra ! lol

]]> By: Nigel Depledge http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/comment-page-1/#comment-124735 Nigel Depledge Fri, 10 Oct 2008 11:32:09 +0000 http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/#comment-124735 Invader Xan - The green colour probably occurs for one of two reasons: EITHER the gas is moving rapidly towards us and its emission is very, very blue-shifted, OR the entire image is false-coloured (as so many astrophotos are), and this material was coloured green to distinguish it from other components of the image. I think the latter is more likely. Invader Xan -

The green colour probably occurs for one of two reasons:

EITHER the gas is moving rapidly towards us and its emission is very, very blue-shifted,

OR the entire image is false-coloured (as so many astrophotos are), and this material was coloured green to distinguish it from other components of the image.

I think the latter is more likely.

]]> By: Information Security http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/comment-page-1/#comment-124209 Information Security Wed, 08 Oct 2008 22:33:05 +0000 http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/#comment-124209 I don't see galaxies colliding, just the FSM and his noodly appendage... I don’t see galaxies colliding, just the FSM and his noodly appendage…

]]> By: Clair http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/comment-page-1/#comment-123973 Clair Wed, 08 Oct 2008 13:47:46 +0000 http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/#comment-123973 "Now, that line sounds pretty mundane, but think about it: entire galaxies collide! They slam into each other at hundreds of kilometers per second! Billions of stars interact gravitationally! Gas clouds impact creating cosmic fireworks on an epic scale! AIIIIEEEE!!!!!! Phew. OK. That’s outta my system now." Phil, I love your enthusiasm! :-) “Now, that line sounds pretty mundane, but think about it: entire galaxies collide! They slam into each other at hundreds of kilometers per second! Billions of stars interact gravitationally! Gas clouds impact creating cosmic fireworks on an epic scale! AIIIIEEEE!!!!!!

Phew. OK. That’s outta my system now.”

Phil, I love your enthusiasm! :-)

]]> By: Johnny Vector http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/comment-page-1/#comment-123971 Johnny Vector Wed, 08 Oct 2008 13:27:32 +0000 http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/#comment-123971 @Invader Xan: According to the caption at the NOAO site, "The green filaments seen near the edge-on spiral galaxy in the lower right (NGC 4388) show H-alpha emission with much higher velocities, suggesting that this galaxy might not be related to M86." I assume from context that they mean "higher average radial velocity", not "larger spread of velocity". @Invader Xan:

According to the caption at the NOAO site, “The green filaments seen near the edge-on spiral galaxy in the lower right (NGC 4388) show H-alpha emission with much higher velocities, suggesting that this galaxy might not be related to M86.”

I assume from context that they mean “higher average radial velocity”, not “larger spread of velocity”.

]]> By: Invader Xan http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/comment-page-1/#comment-123968 Invader Xan Wed, 08 Oct 2008 13:13:52 +0000 http://blogs.discovermagazine.com/badastronomy/2008/10/07/galactic-tentacles-of-doom/#comment-123968 Wow. Do you mind if I ask... Those tendrils emanating from NGC 4388 -- they're green. What exactly is being detected there? I'm guessing the warm hydrogen in those red tentacles is giving off H-alpha (hence, red). Are the green ones emitting H-beta? Or is it something else? (Sorry to go all technical there! :) ) Wow.

Do you mind if I ask…

Those tendrils emanating from NGC 4388 — they’re green. What exactly is being detected there?

I’m guessing the warm hydrogen in those red tentacles is giving off H-alpha (hence, red). Are the green ones emitting H-beta? Or is it something else?

(Sorry to go all technical there! :) )

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