Galaxies are often found in clusters, with many ‘red and dead’ neighbors that stopped forming stars in the distant past. Now an international team of astronomers, led by Andra Stroe of Leiden Observatory and David Sobral of Leiden and the University of Lisbon, have discovered that these comatose galaxies can sometimes come back to life. If clusters of galaxies merge, a huge shock wave can drive the birth of a new generation of stars – the sleeping galaxies get a new lease of life. The scientists publish their work in the journal Monthly Notices of the Royal Astronomical Society.
A radio image highlighting the shock wave (seen here as the bright arc running from bottom left to top right) in the ‘Sausage’ merging cluster, made using the Giant Metrewave Radio Telescope. The shock wave was generated 1 billion years ago, when the two original clusters collided, and is moving at a very high speed of 9 million kilometers per hour.
More http://bit.ly/1GRoWMh
'via Blog this'
No comments:
Post a Comment