Columbia Undergrads Gain Research Experience at Universidad Católica's Astrophysics Institute

Yasmeen Asali and John Staunton, two undergraduate students from Columbia University's Astronomy Department, spent two months in Chile at Universidad Católica’s Astrophysics Institute (UC) as part of an ongoing exchange program funded by the President's Global Innovation Fund (PGIF).

The collaborative program, directed by Marcel Agüeros at Columbia and Gaspar Galaz at UC, has previously benefited five graduate students from both institutions. This iteration marked the first time undergraduate students participated, thanks to the efforts of Frits Paerels, Director of Undergraduate Studies at the Astronomy Department, and the support of the Santiago Center. “Chile holds a place of primary importance in astronomy because it has superb locations for observation and access to the most advanced facilities,” said Paerels. “For our students to go there is a unique and career-changing opportunity that will attract the best students to Columbia,” he added.

Yasmeen, a second-year astrophysics major, worked under the supervision of Andreas Reisenegger and Germán Gómez-Vargas on indirect dark matter detection using the Cherenkov Telescope Array (CTA), a next-generation high-energy gamma-ray telescope projected for completion in 2025, with arrays located in the northern and southern hemispheres (La Palma, Spain, and Paranal, Chile, respectively). She analyzed simulated CTA data of the galactic center in search of gamma-ray signals produced by dark matter annihilation. “The galactic center is ideal for this search because the high dark matter density allows for a higher probability of annihilation, and thus a stronger signal,” she explained. “Emission from known sources in the galactic center is subtracted from the simulated data, leaving a residual image that is compared to models of the expected gamma-ray output from dark matter annihilation.” Yasmeen worked on methods of fitting projected signals to the data to determine an efficient analysis method that could quickly place constraints on dark matter models as soon as the telescopes become operational.

“Yasmeen demonstrated tremendous motivation on the project with a strong commitment to finishing it on time. She worked on setting up a tutorial on data analysis for dark matter searches with the CTA, which will be a starting point for future students in our team,” explained Gómez-Vargas. “She not only created the tutorial on a well-documented Jupyter Python notebook but was also deeply involved in the CTA observation strategies and the theory behind dark matter.”

Yasmeen actively participated in ANSWERS group meetings, providing regular reports and interacting with other group members working on various topics. “I foresee a bright future in science for Yasmeen; she is motivated, proactive, eager to learn, and possesses well-developed soft skills,” said Gómez-Vargas.

John, a physics major, worked under the guidance of Ezequiel Treister, an expert in Active Galactic Nuclei (AGNs), studying the properties of dual AGNs—galaxy mergers with two active black holes at the center of their respective galaxies—to understand the connection between X-ray emissions outside the nucleus and the merger stage. “For example,” said John, “we showed that shock-heated gas appears outside the nucleus during the intermediate stage.” The data used to study these properties came from the Chandra X-ray Observatory, an advanced telescope with high spatial resolution capable of detecting X-ray emissions from hot gas, allowing him to build on skills he gained throughout the year with Paerels. He also worked on a side project aimed at determining the X-ray luminosity of a newly discovered galaxy that has been deformed due to ram pressure in the galaxy cluster Abell 2670.

According to Treister, John not only successfully analyzed the Chandra archival data for nearby galaxies undergoing major mergers but also conducted a deep and careful study of the extended X-ray emission in these systems. “To the point that beyond his most remote expectations, Staunton produced a draft of a paper that was circulated among members of our research group, received very positive feedback, and will soon be submitted to the Astrophysical Journal,” he explained. “I’ve never seen an undergraduate student before who was able to produce a high-quality paper like this one in only a couple of months, starting the project from scratch.”

In addition to their research projects, John found time to expand his interest in physics and astrophysics by presenting two papers at weekly seminars held at UC. “This experience and the setting in which it occurred helped foster an irreplaceable love for physics and astrophysics,” he said upon completing his internship.