The Indian Catholic priest and astrophysics researcher who found conclusive evidence of a long-lost galaxy called M32p,the third biggest after Andromeda and the Milky Way,M32p is considered as the sibling of our galaxy the Milky Way.
Fr. Richard D’Souza SJ is not a typical scientist that one would hear about.The Goa native who is currently pursuing his postdoctoral research at the University of Michigan.
According to scientists, the M32p was ‘swallowed’ by Andromeda, the largest galaxy in our celestial neighbourhood, around two billion years ago.This celestial cannibalization was discovered from the evidence it had left behind – a halo of stars larger than Andromeda.
The discovery was made by a team of researchers led by Fr Richard D’Souza SJ and Eric Bell of the University of Michigan using computer models and simulations.According to him Andromeda which is enormous has swallowed many small galaxies.In an interview with HT D’Souza said “People had given up on this and had moved to other problems. We kept plodding along, and finally we had a breakthrough. We realised that we had to unlearn and abandon so many things we thought we knew.”
Part of the problem lay in the fact that a galaxy like Andromeda was expected to have consumed hundreds of its smaller companions. The researchers thought this would make it difficult to learn about any single one of them.More importantly this discovery and its method will now pave the way for the discovery of other galaxies that have been cannibalized by other larger galaxies.
Using new computer simulations, the scientists were able to understand that even though many companion galaxies were consumed by Andromeda, most of the stars in the Andromeda’s outer faint halo were mostly contributed by shredding a single large galaxy.Discovering and studying this decimated galaxy will help astronomers understand how disk galaxies like the Milky Way evolve and survive large mergers.
Their discovery could alter the traditional understanding of how galaxies evolve. The duo realised that the Andromeda’s disk survived an impact with a massive galaxy, which would question the common wisdom that such large interactions would destroy disks and form an elliptical galaxy.
The timing of the merger may also explain the thickening of the disk of the Andromeda galaxy as well as a burst of star formation two billion years ago, a finding which was independently reached by French researchers earlier this year.