The MUSE ( Multi Unit Spectroscopic Explorer ) instrument of ESO’s VLT ( Very Large Telescope ) has managed to capture a very striking snapshot for astronomy and not easy to see: that of a spectacular cosmic accident. In the image, the movement of the gas can be observed for the first time as it is ripped from the galaxy ESO 137-001 to be quickly swallowed up by a huge cluster of galaxies .
The researchers, led by Michele Fumagalli, from the Extragalactic Astronomy Group and the Institute of Computational Cosmology at the University of Durham (UK), were studying a spiral galaxy that is 200 million light-years away from Earth . in the southern constellation of Triangulum Australe (the southern triangle).
What they have been able to achieve thanks to MUSE is not just a mere image of the event, but a spectrum -or band of colors- for each pixel of the image, finally obtaining the most detailed map of what has happened to this galaxy. as it plunged into the Norma Cluster (a cluster of galaxies located at the center of the Great Attractor, a gravitational anomaly of intergalactic space located at the center of the Virgo supercluster, dragging galaxies across a region of millions of years light).
Thanks to MUSE, astronomers have been able to determine why star formation is deactivated in galaxy clusters , an ancient puzzle so far unsolved. Thus, the galaxy is stripped of most of its gas, the energy or material necessary to make the next generation of young blue stars, but the responsible for stripping the galaxy is not gravity, but the gas of the cluster .
“Finding out how and why galaxies in clusters evolve from blue to red over a very short period of time is one of the main tasks of modern astronomy . Observing a galaxy, just when it changes from blue to red, allows us to investigate how it happens ”, explains Michele Fumagalli, the study leader.
“With the details revealed by MUSE we are getting closer to a full understanding of the processes that take place in such collisions . We can see in detail the movements of the galaxy and the gas, something that would not be possible without this new and unique instrument. These, and future observations, will help us develop a clearer idea of what is driving the evolution of galaxies ”, says Matteo Fossati, co-author of the work.
