Galaxies reached their busiest star-making pace about 11 billion years ago, then slowed down. Scientists have puzzled for years over the question of what happened. Now researchers have found evidence supporting the argument that the answer was energy feedback from quasars within the galaxies where stars are born.
Fierce flashes of light ripple through delicate tendrils of gas in this new image, from ESA’s Herschel Space Observatory, which shows the dramatic heart of a large and dense cosmic cloud known as Mon R2 in the constellation Monoceros that lies eight degrees east of the Orion Nebula. Mon R2 lies some 2700 light-years away and is studded with hot, newly-formed stars.