Thursday, March 13, 2008

Double Galaxy

I discovered a double galaxy a few weeks ago, and it's turning out to be a rather interesting object. Have a look at the Sloan Digital Sky Survey image below. Keep in mind that this object is almost two billion light-years away

It appears to be a giant elliptical galaxy, and quite red. The redness means this galaxy is comprised of old stars and is no longer forming new ones. If you squint your eyes a bit, you can see the double nucleus. The separation is about 9,000 light-years, which makes it one of the closest doubles of this type ever observed. On the sky, however, the separation is a little more than an arcsecond (there are 3,600 arcseconds in one degree). It's amazing what telescopes can do.

Notice that the object is in a crowded field, which looks to be a galaxy cluster. What likely happened is that two large galaxies in the cluster collided and are in the final stages of merging to form a supergalaxy. Here's a pretty picture of a relatively nearby galaxy merger

NGC 2207 and IC 2163 in the constellation Canis Major (STSci)

Mergers are fairly common (we're currently on a collision course with the Andromeda Galaxy), but what makes my object interesting is the activity coming from the double nucleus. From the spectrum it appears that the two supermassive black holes (one in each nucleus) are actively feeding on gas and stars, and the energy produced by this is exciting gas several light-years from the black holes. This is a type of active galaxy. It's also an x-ray source, so I'm submitting a proposal to observe it with the Chandra X-Ray Observatory. At the same time I'm asking for time on the Hobby-Eberly Telescope to get a detailed spectrum for each nucleus.

Any details I can get about this object could help constrain galaxy merger models. Mergers appear to be the primary mechanism for growing giant galaxies and the biggest black holes in the universe, so the more data we can gather the better we can understand how the biggest structures in the universe formed and evolved.

Meanwhile, I usually come up with names for my objects, so any suggestions?


Blogger carnaby said...

Bevis and Butthead?

Ren and Stimpy?

3/13/2008 3:38 PM  
Blogger Stickwick Stapers said...

Hmm... I didn't think of giving it two names.

Kirk and Spock is more my speed. :-)

3/13/2008 7:49 PM  
Blogger Gringo_Malo said...

Big Red?

Sorry, creativity's in short supply on a Friday afternoon.

3/14/2008 11:24 AM  
Blogger Yuri Orlov said...

My kids favorite sandwich:


3/14/2008 11:28 AM  
Blogger Mr. Completely said...

Smith & Wesson?

If that's too obvious, how about John-Moses?

.... Mr. C.

3/17/2008 9:29 PM  
Blogger Stickwick Stapers said...

All good suggestions. (Esp. Smith & Wesson.) But I went with "Bert & Ernie."

3/20/2008 9:06 AM  

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