Scientific News

ESA: Herschel paints new story of galaxy evolution

January 2012 - The rate of star formation peaked in the early Universe, about 10 billion years ago. Back then, some galaxies were forming stars ten or even a hundred times more frequently than our galaxy does today. Such high birth rates are very rare in the nearby, present-day Universe, and always seem to be triggered by galaxies colliding with each other. So astronomers assumed that this had been true throughout history.

Using the European Space Agency (ESA)’s Herschel infrared space observatory, however, astronomers have recently looked at galaxies that are very far away, and have thus seen them as they were billions of years ago. This peek into the past revealed that galaxies do not need to collide with each other to drive vigorous star birth. The finding overturns this long-held assumption and paints a clearer picture of how stars form – and galaxies evolve.

For more information, see the research publication:
Elbaz D et al. (2011) GOODS–Herschel: an infrared main sequence for star-forming galaxies. Astronomy & Astrophysics 533: A119. doi: 10.1051/0004-6361/201117239