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A recent intergalactic discovery making headlines around the world has an Indian connotation. Earlier this week, it was widely reported that scientists Richard D & Souza and Eric Bell of the University of Michigan had deduced that the Milky Way had a brother, who was devoured by the neighboring galaxy. Andromeda about two billion years ago. The results were published in the journal Nature Astronomy on July 23 and drew attention to their potential to change our understanding of the melting and evolution of galaxies over time. time.
shoot, they bear the risk of collision. In such a case, the larger one usually subsumes the smaller entity. Andromeda, the largest galaxy in the local group of which the Milky Way is part, would have long swallowed up several small galaxies over the years. According to computer simulations, D'Souza and Bell deduced that one of the galaxies with which Andromeda merged was actually a gigantic, third largest in the local group after the Milky Way.
The researchers proposed that the stars of this jagged galaxy eventually surround Andromeda, giving it its light stellar exterior halo, and its intriguing satellite galaxy, M32. Scientists have long been trying to decipher the formation of M32 because it is a rare compact elliptical galaxy (unlike the Milky Way, which is spiral) rich in stars. The new findings suggest that the undestroyed nucleus of the cannibalized galaxy has continued to form M32.
Described in media reports as a brother or sister of the Milky Way, the lost galaxy was named M32p. The results are interesting not only because they indicate that the M32p core survived the collision, but also that the Andromeda disk remained intact despite its fusion with such a large galaxy. This goes against the traditional scientific belief that collisions between entities of this size would have a dramatic impact on the structure of the surviving galaxy.
D'Souza, the chief author of the newspaper, comes from the Indian state of Goa, where still lives his family. He is doing his postdoctoral research at the University of Michigan. Dr. Souza is also a Jesuit priest and staff member of the Vatican Observatory, an astronomical institution supported by the Roman Catholic Church.
D'Souza had long and illustrious academic results and studied an interesting mix of subjects. He was born in 1978 in Pune and spent his early years in Kuwait. In 1990, he moved to Goa, where his family still resides, and joined a Jesuit school. He earned a BSc in Physics from St. Xavier's College in Mumbai, followed by a Masters degree at the University of Heidelberg in Germany. He then returned to Pune and earned a second Bachelor of Philosophy, followed by one in Theology. He earned his Ph.D. in astronomy from the Ludwig University Maximilian is now doing his post-doctorate from the University of Michigan.
In an interview with Scroll.in D'Souza talks about his interesting academic chart how his religious and scientific activities inform each other and what his discovery means for the year. future of the Milky Way. Extracts:
For a layman, how would you explain your recent discovery?
My research focuses on the growth of galaxies through mergers. During its lifetime, a galaxy like Andromeda, our nearest big neighbor, would have fused with hundreds of smaller galaxies, due to the gravitational pulling forces. These small galaxies are destroyed in the process due to the tidal forces of gravity leaving behind a trail of stellar debris (like crumbs) around the main galaxy called stellar halo.
In studying the stellar halo of a galaxy, I developed a technique to infer the size of the largest galaxy that was destroyed in the process. This is similar to guessing what a small child ate after watching the "crumbs" and mess scattered on the floor around her!
Observations from the last decade have shown that Andromeda has the largest stellar halo for any galaxy of its size. We realized that to build such a large stellar halo, Andromeda must have merged with a very large galaxy. We can best understand this through a commercial badogy. Like companies, galaxies also grow through mergers. Now, a business can grow moderately by merging with other small businesses. But if a big company wants to do a growth spurt, it has to negotiate a merger with another big company. Similarly, from the observations of the great stellar halo of the Andromeda galaxy, we deduced that it has merged with a significantly large galaxy (1/4 of its size) there is no not so long ago.
How many years has this discovery been? What was the nature of your research work before that?
We started thinking about this project about a year and a half ago! Last year, we started writing it and we did it in six months. The review process through the Nature Journal took 6 additional months. During my Ph.D. at the Max Planck Institute in Germany, I focused on obtaining observations deep stellar halos of more distant galaxies.
How does this discovery change our understanding of the universe? The press release from the University of Michigan says it could "alter the traditional understanding of the evolution of galaxies."
It was traditionally thought that such mergers destroy the discs of galaxies converting them into spheroidal elliptical galaxies. We now know that the disk of the Andromeda galaxy has survived this particularly important fusion, although we do not know exactly why. So, this discovery upsets a major paradigm in our understanding of the evolution of galaxies. One thing we can remove is that the discs of galaxies are more resilient than previously thought. We hope this discovery motivates further studies to understand under what special circumstances the galactic disks survive such interactions
What is the significance of the fact that the Milky Way had another galaxy sister? How is a galaxy called a sister galaxy?
The Andromeda and the Milky Way are relatively close, and are the largest members of the "Local Group" of galaxies. Astronomers have long studied the local group, including its smaller members, and thought that they knew their neighborhood quite well. We now realize that there was another galaxy there (which we call M32p) which was almost half of the Milky Way and which was destroyed by Andromeda. This comes as a complete surprise! This makes M32p the third largest member of the local group. The next smallest member, the Triangulum galaxy, is at least eight times smaller than the Milky Way. Indeed, M32p was a long lost brother. We joked among ourselves that it was "the missing family member" that no one wanted to talk about
Could the study of the M32p enlighten our galaxy?
The Milky Way currently has a large satellite galaxy called Great Magellanic Cloud, which will merge with it in a future of two billion years. Although the Great Magellanic Cloud is much smaller than M32p, astronomers worried about whether the Milky Way disk would survive the merger. Andromeda and M32p have now taught us that the Milky Way will survive this merger.
Some scientists have talked about the likelihood that Andromeda collides with the Milky Way in a few billion years. Does the consumption of M32p by Andromeda suggest anything more?
The Andromeda galaxy travels to the Milky Way at about 110 km / s, and will eventually collide with it in about four-five billion years. Eventually, our galaxy will be part of the stellar halo around the Andromeda galaxy. In addition, since both galaxies are large and of comparable size and mbad, we believe that Andromeda may not survive the collision and may turn into an elliptical galaxy. This is how the Universe is and how the forces of gravity work. We must remember that in a similar amount of time, our own sun will turn into a giant red star, grow in size and make the earth habitable. This can be a much more immediate concern!
Richard D'Souza / via Facebook [19659014] You Have studied theology, philosophy and physics, it is a set of unusual and fascinating subjects: how do these areas differ? Yes, the study of philosophy and theology m & # 39, allowed me to broaden my thinking, how to criticize the science that I have learned at the University, including its badumptions and its adopted worldview.Theology has helped me to think about deeper issues that motivate all humans: where do we come from, where do we go and what is the meaning of life? I appreciate science, it is a bit restrictive and limited in his approach, philosophy and theology have provided tools to reflect and reflect on a broader set of issues and problems. [19] 659002] is a bit antithetical to science. It is unusual, but not unheard of, to have scientists who are also priests. How do your religious and scientific beliefs interact?
It is rather unfortunate that the Catholic Church has historically made a number of errors regarding science, especially when it has felt its power and doctrine threatened. However, it must also be stressed that the Catholic Church in its own way, through the development of universities in Europe but also through the number of its active members in the sciences over the centuries, has contributed to its development. This part of the story is excluded!
I do not see any fundamental contradiction between my religious and scientific beliefs. In fact, they go together. My religious beliefs tell me that God created the world as something good according to certain laws. This fundamental badumption ensures that the laws of nature are constant and deserve to be studied. That is why science flourished in the West, unlike in other cultures where the gods and therefore the understanding of reality were more capricious and capricious. For me, studying the Universe helps me to learn more about its creator. Therefore for me, studying astronomy, stars and galaxies are an ultimate form of worship.
What made you study religion and become a priest?
I studied at a Jesuit school in Goa and was fascinated by the Jesuits of Goa. It is here that the roots of my vocation have begun. In addition, their long history of working in science has been a huge attraction to me.
Where is the astronomical research in India today? And do you plan to return after completing your postdoctoral research in Michigan?
There are today a number of excellent astronomical centers in India, especially in Pune and Bangalore. Traditionally, research in our country has tended to be more theoretical, but it is changing rapidly. The progress observed generally requires greater investment, particularly in terms of money and resources. Today, optical astronomy is guided by new observational data, which in turn depends on access to the right telescopes, instruments and resources. I think our Indian scientists would be able to make much greater progress if the government invested more in instrumentation.
After my postdoctoral research in Michigan, I intend to return to the Vatican Observatory. I am open to opportunities to research and collaborate with scientists in India!
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