Star 'bubbles' reveal galaxy formation
This young galaxy (NGC 1068) is causing astronomers to rethink how our own galaxy formed. Shown here is a close up composite image taken by the Hubble Space Telescope and the Chandra X-Ray Telescope of the galaxy's active center, thought to contain a massive black hole. Astronomer Robin Shelton of the University of Georgia told EarthSky, "What we're doing is looking for hot gas further out in the extended disc." That disc of hot gas reaches temperatures of 600,000 degrees Fahrenheit. For actual images studied by Dr. Shelton, click here.
NGC 1068 – also called M77 – lies 60 million light-years from Earth, in the direction of the constellation Cetus. It is considered an active galaxy, with a compact source of high-energy radiation at its core.
In 2006, astronomers a surprising lack of interstellar gas in the disk of a distant galaxy.
This discovery might offer clues to the formation of our own galaxy, the Milky Way. The distant galaxy is NGC 1068. It’s a spiral galaxy, thought to be younger than our galaxy, some 60 million light-years away.
Astronomers at University of Georgia examined ultraviolet light from this galaxy. They believe the light comes from hot gases between young stars in this young galaxy. The gases can reach temperatures 100 times that of our sun’s surface. Robin Shelton, who led the study, said this gas is a sign of active star formation in NGC 1068.
Robin Shelton: And when new stars are being made, some fraction of them are very massive stars that blow up pretty early on. And they blow big bubbles full of hot gas. So if you imagine stars exploding, here’s a metaphor for what it’s worth. It froths the galaxies up and makes these bubbles of hot gas.
But Shelton’s team found less gas in NGC 1068 than they expected to find in this younger version of our Milky Way.
Robin Shelton: Maybe we’re just bright by comparison, which would be kind of interesting. If we’re bright by comparison, maybe it means that something has happened to us recently that’s lit up our own sky.
Thanks today to Research Corporation, a foundation for the advancement of science.
Our thanks to:
Robin Shelton
University of Georgia
