Camille Avestruz is a 2019 LSA Collegiate Fellow and assistant professor in the college’s Department of Physics. Her research interests span astrophysics, cosmology, and computation, where she uses simulations to make predictions and interpretations of large-scale cosmic structures. Her primary focus is on understanding the evolution of galaxy clusters.
LSA: How would you describe your field of study? What kind of research are you conducting?
Camille Avestruz: I work in the physics department, which is the largest umbrella that my field of study would fall under. Physics seeks to understand physical systems, from the very big to the very small. If I could describe what I did in two words, it would be “computational cosmology,” which falls under the study of the “very big.” The goal of cosmologists is to better understand the history and contents of the Universe. The computational part means we use computers to analyze data, create models, and perform calculations. I primarily use data from numerical simulations. This means that we simulate what some volume of the Universe might look like; we generate a distribution of matter consistent with what is known about our Universe very early in its history, and we see how things evolve according to equations that describe physical processes like gravitational interactions. One type of astronomical object I am particularly interested in is the most massive gravitationally collapsed of the objects, called galaxy clusters. These are made of hundreds to thousands of galaxies and are 13 to 15 orders of magnitude more massive than our Sun. They are interesting structures because objects do not grow to this mass until relatively late in the history of our Universe, making them a particular tool to better understand cosmology.
LSA: What interested you in astrophysics and machine learning? Are these areas you always knew you wanted to explore?
CA: These were not areas I always thought I would explore. I got into astrophysics when I started graduate school. Before that, I thought I would study experimental particle physics, which is the “very small”—the other end of the size spectrum. I started research in this area during my undergraduate years, and something that was nagging at me was that you must be a Jill-of-all-trades in that field. You have to build circuits, machine materials, work with various pieces of hardware while also analyzing massive amounts of data coming out of these experiments, which requires an understanding of coding. I realized I wanted to buckle down and get good at a narrower set of things to feel like I was honing a skill set. I fell into computational work after meeting a professor, who would later become my advisor, at my graduate school’s visiting weekend. He was so excited about what he was working on, and computational astrophysics had a lot of cool visual aspects to it. I have often leaned towards visual learning to gain intuition, so this made a lot of sense to me. It was not until 2014, during the latter portion of my graduate studies, when machine learning sparked my interest. I attended a lecture in New York City by the winner of a Kaggle competition to classify galaxies. (Kaggle is a competition among data scientists to construct the best performing algorithms for different tasks). I was struck by how the winning submission largely boiled down to a clever use of “data augmentation” to improve performance. I realized there were things I could do with this in my field, too.
LSA: Why should your research matter to the average person? What’s the “big picture”?
CA: Studying cosmology is like uncovering one big origin and evolution story. I think we all have some kind of drive to understand why we are here and how all this came to be. There are still major mysteries and unknowns. For example, most of the matter in our Universe is matter we do not understand—dark matter. It is called that because it does not emit or reflect light the way everything else does. We have not been able to directly detect it in a lab setting to study its properties; we only know of its existence because we can infer its presence through gravitational interactions with luminous matter. Another major mystery is why our Universe appears to be expanding at an accelerating rate. It’s weird and has to be due to something that effectively pulls things apart, which we call dark energy. Late in the history of our universe, until now, we have been in a dark energy dominated era when the effects of dark energy strongly affect how structures, like galaxy clusters, have evolved. Galaxies that could collapse into objects like galaxy clusters get pulled apart because of this accelerating expansion, counteracting the gravitational pull. Dark energy suppresses the formation of galaxy clusters. Therefore, galaxy clusters are a direct imprint of both dark matter and dark energy—both of which we do not fully understand yet.
Besides discovering more about our origin and evolution, though, there are other reasons I think folks should care. If we can get kids and adults excited about science, the field of study offers an opportunity to strengthen critical-thinking skills. Critical thinking is an important skill, even if you don’t become a scientist. Also, cosmology might be considered basic science research, or a curiosity-driven field, but this kind of work pushes developments that have applications that directly benefit society. Basic science drives technologies we will use later to improve our lives.
LSA: You mention you’re passionate about making STEM accessible to those who have been historically excluded from the sciences and the academy. What does that mean, and why is that a cause you’ve undertaken?
CA: Growing up, my family treated education as a value and it was seen as a clear path towards financial stability. Unfortunately, though, access to quality education does not exist for everyone in the U.S., though it should. When I look at how I got to where I am now, I can recognize that I had privileged opportunities. This includes access to a private boarding school on a full scholarship. Here, I received focused attention and mentorship, and well-curated classes. I was offered opportunities to engage in areas I was interested in and to develop certain skills. Access is not just the school you go to; it is also knowing how to apply there in the first place and having the finances when scholarships are not available. Access is having already developed skills and self-confidence to identify ways to engage in conversation and to feel like you deserve to be there, and that your voice matters. So, I want to give back as much as possible, and especially in areas I occupy with some amount of power. What things are in my power to mitigate lack of access? Can I help shift dynamics in the room that I am in?
LSA: What do you hope students gain or take away from your research?
CA: Regarding undergraduate students, I hope they feel like what they are learning, in whatever kind of physics class they’re taking, connects to something cool. I also hope students who may participate in research, more generally, are refining their skills to ask and answer questions in every step of the scientific process.
*This interview has been edited for length and clarity. Camille Avestruz is a 2019 LSA Collegiate Fellow. This story is part of a series highlighting the research of LSA Collegiate Fellows, a program of the National Center for Institutional Diversity (NCID) at the University of Michigan. The LSA Collegiate Fellows is one of the most innovative programs in higher education, recruiting and retaining faculty who are experts in their fields and have demonstrated commitments to diversity, equity, and inclusion through their scholarship, teaching, and/or engagement.
