Zombie galaxies live again

Seemingly dead galaxies apparently burst back to life and form new stars

- Prof Chris Lintott

Finding out how star formation stops is one of the biggest problems in astrophysics. On average, as the Universe ages, galaxies shift from being rich in star formation, lit up by the brilliant blue light of massive new stars, to quiescent, quiet places.

The process is known as quenching, but a new study making use of data from the Hubble Space Telescope suggests that quenched galaxies might not be as dead and dull as previously thought.

Led by Michael Rutkowski in Minnesota, the authors have identified what we might call 'zombie galaxies', quenched but still undergoing sporadic and really quite significant bursts of star formation.