“Cosmic joust”: astronomers observe pair of galaxies in deep-space battle – ESO Press Release

Astronomers have witnessed for the first time a violent cosmic collision in which one galaxy pierces another with intense radiation. Their results, published today in Nature, show that this radiation dampens the wounded galaxy’s ability to form new stars. This new study combined observations from both the European Southern Observatory’s Very Large Telescope (ESO’s VLT) and the Atacama Large Millimeter/submillimeter Array (ALMA), revealing all the gory details of this galactic battle – Read the full story on ESO Press Release

This image, taken with the Atacama Large Millimeter/submillimeter Array (ALMA), shows the molecular gas content of two galaxies involved in a cosmic collision. The one on the right hosts a quasar –– a supermassive black hole that is accreting material from its surroundings and releasing intense radiation directly into the other galaxy - Credit: ALMA (ESO/NAOJ/NRAO)/S. Balashev and P. Noterdaeme et al.
This image, taken with the Atacama Large Millimeter/submillimeter Array (ALMA), shows the molecular gas content of two galaxies involved in a cosmic collision. The one on the right hosts a quasar –– a supermassive black hole that is accreting material from its surroundings and releasing intense radiation directly into the other galaxy. 
Astronomers used the X-shooter instrument at ESO’s Very Large Telescope (VLT) to detect the quasar’s light as it passes through an invisible halo of gas surrounding the galaxy on the left. In doing so, they could observe the damage that this radiation causes to the victim, disrupting its clouds of gas and hampering its ability to form new stars.

Credit:ALMA (ESO/NAOJ/NRAO)/S. Balashev and P. Noterdaeme et al.