Once there were three galaxies in the local group – Andromeda (M31), the Milky Way and its sister, the M32p galaxy. About two billion years ago, Andromeda was able to explode and destroy M32p, leaving a trail of cosmic debris as evidence.
It was the perfect crime, until now.
Scientist Fr Richard D & # 39; s Souza SJ and Eric Bell at the University of Michigan used computer models and simulations to show Andromeda's dark past. Their research suggests that Andromeda's compact M32 satellite galaxy is indeed the cored core of the destroyed M32p. Their results were published last week in Nature Astronomy .
D & # 39; Souza, the main author of the newspaper, was born in Mapusa (Goa), graduated from St. Xavier's College in Mumbai and made most of his priesthood in India. In an e-mail interview, the Jesuit and the scientist tell us about his work and the interface between science and faith in his life.
Tell Us About Your New Findings and Their Importance
My research focuses on how galaxies grow through mergers , It is believed that a galaxy like Andromeda, our next big neighbor, is fused with hundreds of smaller galaxies. These smaller galaxies are destroyed by the tidal forces of gravity, leaving a trail of stellar debris (such as "crumbling") around the main galaxy called their stellar halo.
By studying the stellar halo of a galaxy, I have developed a technique to deduce the size of the largest galaxy that has been destroyed. This is akin to guessing what a little kid ate after seeing the crumbs and mess on the floor. Observations over the past decade have shown that Andromeda has the largest stellar halo for any galaxy of its size. We realized that not so long ago, Andromeda must have merged with a really big galaxy (a quarter of its size) to build such a large stellar halo.
How will the discovery of this decimated galaxy help the future? Research and Study
Traditionally, it has been suggested that such large fusions destroy galaxy slices and turn them into elliptical spheroidal galaxies. We now know that the slice of the Andromeda galaxy has survived this particularly large fusion, though we do not know exactly why. This realization leads to a fundamental paradigm in our understanding of galaxy evolution. One thing we can remove is that the disks of galaxies are more resistant than previously thought. We hope that this finding will motivate further investigation to understand the circumstances that will cause the disks of galaxies to survive such large interactions.
The next part of my research involves studying the stellar haloes and the fusion histories of other distant galaxies to understand which of the galaxy's properties are caused by the fusion.
Will this help help solve the mystery of Andromeda's M32 satellite galaxy?
We think so. We have only suggested one model and it needs to be tested and verified. While everyone agrees that Andromeda had a big collision two billion years ago, some scientists doubt whether this collision has led to M32. Such a disagreement is good. Science is a conversation, a back and forth, and we will come to the iterative truth.
Speaking of Controversy: How Do Faith and Science Intersect for You?
For me these are two very basic ways to know the same reality. Humanity needs both, to know that way, to understand reality, and to move forward in life. Science is based on assumptions and beliefs. Especially in astronomy, where it is very difficult to prove something exactly, it surprises me how much is really based on assumptions and beliefs.
According to philosophy, meaning can not be found within a system, but only externally. Science can not offer us meaning in life, only something that is completely transcendent, like the divine. Without meaning, we will not go forward, we will have no hope, we will not strive to do the things we do, and without hope, people will have nothing to look forward to. Religion and faith make sense to us, and that often gives us a good reason to do good science, for it becomes an expression of reaching that transcendent, that is, God.
Is that attracting you to science? ?
I've always been interested in science. As a kid I loved to build things and computers. At school I got to know physics. My Jesuit superiors encouraged me to learn astronomy because there was a rich tradition of Jesuits studying and researching astronomy. After my ordination and my time in Goa, I returned to the natural sciences and graduated in astronomy.
My major subject is galaxy formation and evolution. This field seeks to understand the rich variety of galaxies that we see in the universe. Where and how did it all start? Which path did the universe take to get here?
How did you start working for the Vatican Observatory?
The Jesuits lead and direct the Vatican Observatory. As soon as I started my Master in Physics in Heidelberg, they reached me. After my PhD in 2016, I officially came to the staff of the Vatican Observatory. Although I'm connected to them, I went to the University of Michigan for a post-doc, and occasional short visits back to the observatory in Rome or their offices in Tucson.
Most astronomers at the Vatican Observatory are Jesuits if not Catholic priests and brothers. The place has the right combination of science and belief. In addition, the members have such good connections and friends around the world; It opened a lot of doors for me.
Does your work and research enhance your spiritual life?
I usually try to keep the two apart, but it does not really work. I often preach about the harsh research process and the spiritual teachings that can be learned from it. When I am depressed and disappointed in my research, I pray for inspiration and God's help. My spiritual life and my research work intertwine seamlessly.
In an interview you mentioned that most people misunderstand the attitude of the Catholic Church towards science and creation. How are you?
Most people misunderstand the current doctrine of creation of the Catholic Church. It teaches us that God created the world but does not insist. The Church agrees with modern biblical scholarship that the first chapters contain many key theological truths about the human person and the relationship to the world and to God, but not literally or historically.
The idea of the Church of creation is not in complete contrast to science and history. Father George Lemaitre, a Belgian Catholic priest, was the originator of the idea of the Big Bang in the 1930s after applying Einstein's Theory of Relativity to the universe. The big bang is a very catholic idea!
The knowledge of belief in the average Christian is quite limited. We were taught some things as children and then our religious education stopped after the 13th or 14th year. Our religious knowledge remains at the level of children. On the other hand, we spend a lot of time and energy training us professionally. I only wish that Catholics do the same and stay up to date with their faith education.