Scientists theory about the method by which galaxies expand was confirmed when the Messier 87 galaxy was observed essentially consuming another galaxy. It is a first for astronomers to be able to observe a galaxy growing in size by absorbing the stars from other galaxies.
The observations were made by Alessia Longobardi, a PhD student at the Max Planck Institute, led the team of researchers, who used the European Southern Observatory’s.Astrophysical Research Letters journal published the result of their study.
The telescope was used to monitor the movement of the planetary nebulae surrounding aging stars, leading researchers to believe that an impact that has occurred within the last billion years suggesting that a medium-sized galaxy had been sucked into the center of the Messier 87 galaxy.
A galaxy that is now 100 times larger than the original one, has stars scattered throughout the area.
The giant elliptical galaxy Messier 87, also called Virgo A, is one of the most remarkable objects in the sky. It is perhaps the dominant galaxy in the closest big cluster to us, the famous Virgo Cluster of galaxies, and lies at the distance of this cluster (about 60 million light-years). M87 lies well in the heart of the Virgo cluster (together with a lot of galaxies including M84 and M86).
“This result shows directly that large, luminous structures in the Universe are still growing in a substantial way – galaxies are not finished yet!” Longobardi stated in a press release.
Because of the impact with another galaxy, the outer halo of Messier 87 is twice as bright.
“It’s exciting to be able to identify stars that have been scattered around hundreds of thousands of light years in the halo of this galaxy – but still to be able to see from their velocities that they belong to a common structure.” Another co-author of the study, Magda Arnaboldi, stated.