How to make a supermassive black hole

Apparently, the recipe is:
Step 1 - Crash two galaxies together
Step 2 - Wait for the two smaller black holes at the center of these galaxies to merge together, during which time lots of gas falls into them.
Step 3 - Go to Step 1.

Figuring this out was not as simple as it looks. Go here,
here, and here, and here to learn more.

Ancient star formation

Go here to read how galaxies in some of the earliest known galaxy clusters in the universe are producing stars at a much higher rate than now. Interesting...

One Ring to Surround Them All

GALEX, an ultraviolet satellite, recently discovered rings of ultraviolet light (only produced by young, massive stars) around the core of galaxies which show no sign of ongoing star formation. Go here and here and here to read what is going on!

How to mix up a galaxy

Collide it with another one, of course. Go here to learn what exactly I'm talking about.

Where have all the galaxies gone?

Maybe they were always there all along? Go here to read what I'm talking about. Very interesting to me, at least - hope you find it interesting too. Enjoy

Distant Star Formation

By using the magnification resulting from gravitational lensing caused by a massive galaxy cluster coincidentally sitting between us and distant galaxy SMM J2135-0102, astronomers were able to map out where stars are forming in this galaxy - which happens to be forming ~250 new stars every year! Go here for more details. Interesting.

Young Supermassive Black Holes?

Astronomers believed that at the center of essentially every galaxy is a supermassive black hole (supermassive = more material than a million Suns. Some are believed to have a mass more than a billion times that of the Sun). Where these black holes come from, no one really knows, but they gain mass by accreting (think swallowing) the surrounding gas. This gas forms a disk as it falls into the black hole, in which gas particles can stick together to form molecules - which astronomers call "dust." The older the disk, the more dust that should be there - or so goes the current thinking. By this logic, using Spitzer astronomers just found a couple supermassive black holes with very young disks. Go here to read more. Not necessarily the most convincing argument, but interesting nevertheless.

A modern day astronomical fossil

Astronomers currently believe that when the universe was a billion years old or so (as opposed to the 14 billion years old it is now), it was full of small galaxies which were merging together to form bigger ones - and it was by this process that all of the big galaxies we see today were formed. Wouldn't it be great if we could somehow observe the same thing nearby, so we can study it better? Well, Hubble and GALEX may have discovered such an example. Go here for the details. Enjoy!

Another really old star

Just like the ESO press release above, another group of astronomers have looked at a dwarf galaxy (this time, Sculptur) and found another star that dates back to around the time the first stars ever formed. Go here to read more about this discovery. Exciting!

The Oldest Stars in the Universe

Believe it or not, but I hope you do, the lifetime of stars with masses less than that of the Sun is similar to that of the current age of the universe. That means that such stars born at early times should still be around today. (This does NOT mean that all stars with mass less than the Sun's were born at these early times.) Do you we expect any such stars in the Milky Way? Yes. Astronomers currently believe that the Milky Way formed from the merger of several smaller galaxies which should have been full of such stars. Is there anyway of identifying them? Yes. Since elements heavier than Lithium or only produced by stars, old stars should have a smaller percentage of such metals than younger ones because the material they were formed out of had fewer such metals. Do we know of many such stars? No. Why am I rambling about this? Well, astronomers might have finally found many of these missing low-metal, low-mass stars. Go here to read more. Enjoy!

Picture Book of Galaxy Evolution

Go here to see the result of a deep, multi-wavelength survey of one patch of sky designed to study how galaxies evolve with time. It is more than just a very pretty picture, honest.

Merge Galaxies on your computer!

In my opinion ne of the best astronomer projects out there, Galaxy Zoo, has branched out to cover galaxy mergers. Go here for more information. Enjoy!

Investigating a Galaxy's "stomach"

As I've discussed on previous shows, astronomers believe that the major way galaxies grow is by merging with other galaxies. Read here how astronomers have detected the remnants of one of these mergers in a nearby galaxy, Centaurus A. Hope you enjoy!

January 28th Radio Show: Galaxy Formation and Evolution

Sorry for the delay, but here is the January 28th edition of this radio show, where I continue my discussion of galaxy formation and evolution. Thank you for listening, hope you enjoy, and, as always, please email me or leave below any questions, comments, or concerns you might have.