Where do new stars form in galaxies?
Spiral galaxies like our own Milky Way are studded with cold clouds of hydrogen gas and dust, like chocolate chips in a loaded Toll House cookie.
Astronomers have long focused on these so-called molecular clouds, suspecting that they are hotspots for star formation. But are they?
After a thorough analysis of the molecular clouds in a nearby spiral galaxy, an international team of astronomers has found that, while star formation starts up rapidly in these clouds, the newly formed stars quickly disperse the cloud – in as little as a few million years – stopping further star formation. So while star formation in cold molecular clouds is fast, it’s highly inefficient.
The findings by a collaboration led by Diederik Kruijssen from Heidelberg University will help astronomers understand where and when stars form in galaxies, which in turn determines how galaxies change over their lifetimes.