November 13, 2014: Hubble has uncovered young, massive, compact galaxies whose raucous star-making parties are ending early. The firestorm of star birth has blasted out most of the remaining gaseous fuel needed to make future generations of stars. Now the party's over for these gas-starved galaxies, and they are on track to possibly becoming so-called "red and dead galaxies," composed only of aging stars. An analysis of 12 merging galaxies is suggesting that energy from the star-birthing frenzy created powerful winds that are blowing out the gas, squelching future generations of stars. This activity occurred when the universe was half its current age of 13.7 billion years.
The graphic illustrates how a vibrant, star-forming galaxy quickly transforms into a sedate galaxy composed of old stars. The scenario begins when two galaxies merge (Panel 1), funneling a large amount of gas into the central region. The gas compresses, sparking a firestorm of star birth, which blows out most of the remaining star-forming gas (Panel 2). Devoid of its fuel, the galaxy settles into a quiet existence, composed of aging stars (Panel 3).See the rest: