Lead authors (IMAGE) Stockholm University Caption Erik Kool (center) and Joel Johansson (left) are post-docs at the Oskar Klein Centre at Stockholm University and lead authors of this paper together with professor Jesper Sollerman (right) from the Department of Astronomy. Photo: Magnus Näslund Credit Photo: Magnus Näslund Usage Restrictions Free for media/editorial use. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.