View Full Version : Colliding Spiral Galaxies Captured by Hubble

2006-Oct-18, 12:50 AM
This Hubble photograph shows two spiral galaxies colliding together. Known as the Antenna Galaxies, aka NGC 4038-4039, these two galaxies started interacting a few hundred million years ago. Thanks to the galactic interaction, perturbed gas clouds in both galaxies collapse into regions of furious star formation (these are the blue regions). Most of these regions will disperse their stars into galactic disks, but some will remain on as super star clusters - similar to the globular star clusters we see in our Milky Way.

Read the full blog entry (http://www.universetoday.com/2006/10/17/colliding-spiral-galaxies-captured-by-hubble/)

2006-Oct-18, 11:52 AM
This is an interesting image. One thing that caught my eye was that there is tremendous star-forming going on in certain regions, but in the centers of the two former galaxies, there is almost none. Has the gas there been unaffected? has it previously been depleted? I don't know why the star forming is going on in the isolated areas that it is in.

2006-Oct-18, 07:39 PM
My guess is that the two gas disks haven't completely collapsed yet. If the simulations are anything to go by, the bulk of the cold gas will be dumped on the new, merged bulge and a good fraction of it will form stars then. It will then probably become a LIRG/ULIRG. What's L_{FIR} of the Antennae?

2006-Oct-19, 01:44 AM
Could it have something to do with shockwaves? Maybe "newer", faster shockwaves are catching up with older, slower shock waves, and this creates denser regions where starforming is more abundant. I seem to recall reading about something like this happening in bubble nebulas.