UMD Astrophysicist Sasha Philippov Awarded 2024 Sloan Research Fellowship
He will use the award to continue studying plasmas surrounding black holes and neutron stars.
Sasha Philippov, an assistant professor in the University of Maryland’s Department of Physics, is one of 126 scientists in the United States and Canada to receive a 2024 Sloan Research Fellowship.
Granted by the Alfred P. Sloan Foundation, the $75,000 award recognizes scientists who have made important research contributions and have demonstrated “the potential to revolutionize their fields of study.” The fellowship, introduced in 1955, is considered one of the most competitive and prestigious awards that an early-career scientist can receive. To date, 71 UMD faculty members have earned this distinction, including 14 from UMD’s College of Computer, Mathematical, and Natural Sciences since 2015.
Fellows are nominated by other scientists and selected by independent panels of senior scholars. Philippov was nominated by Eliot Quataert, a theoretical astrophysicist at Princeton University who said that Philippov’s research “stands out” from his peers covering similar topics.
“Sasha has a combination of physical intuition, physics depth, code development skills and computational acumen that is characteristic of the very best computational astrophysicists I have interacted with in my career,” Quataert said.
Philippov, who holds a Ph.D. in astrophysical sciences from Princeton, was previously named a NASA Einstein and Theoretical Astrophysics Center Fellow at UC Berkeley, where he completed a postdoctoral fellowship from 2017 to 2018.
After his postdoc, Philippov worked as an associate research scientist at the Simons Foundation’s Flatiron Institute, where he constructed the first models capable of explaining the mysterious coherent emission of pulsars—magnetized neutron stars that rapidly rotate.
Since joining UMD in 2022, Philippov has been busy with several research projects. He used simulations to show the production of gamma-ray flares from the black hole in galaxy M87, which was the first black hole to be pictured. He also demonstrated how kinetic effects change the flow of plasma and produced proof-of-concept simulations of radiative plasma turbulence.
Philippov also serves as deputy director of a Simons Foundation project called the Simons Collaboration on Extreme Electrodynamics of Compact Sources that models electrodynamic processes related to neutron stars and black holes.
Looking ahead, the two-year Sloan Research Fellowship will enable Philippov to delve deeper into the study of plasmas—hot, ionized gas that surrounds neutron stars and black holes, which he describes as “some of the most mysterious and exotic objects in the universe.”
Part of Philippov’s research will involve the study of magnetars, which are neutron stars with the strongest magnetic fields in the universe. He plans to use advanced 3D simulations to better understand the powerful magnetic flares that occur when pulsars release magnetic energy, enabling scientists to connect the dots between what is observed through telescopes and what is actually occurring at a magnetar’s surface.
He will also investigate black holes that accrete plasma “very efficiently,” meaning more plasma falls into those black holes than ones that accrete low-density plasma, such as the one in M87.
“Depending on how much falls in, the properties of the plasma are quite different because their temperatures and density are different,” Philippov explained.
For Philippov, more plasma means more opportunities to study neutrinos, which are weakly interacting particles that can be generated in the environment surrounding black holes. Philippov’s ultimate goal is to create models that explain how protons accelerate and end up producing neutrinos.
The timing is ideal, considering that the IceCube Neutrino Observatory at the South Pole recently detected neutrinos from a spiral galaxy called NGC 1068.
“There will be more observations with IceCube and future detectors, so it’s a good time to work on theoretical models,” Philippov said.
Ultimately, Philippov is excited to study the phenomena that help illuminate objects like black holes, which do not emit light on their own. In pictures of black holes, what we sometimes see are accretion disks, or rotating rings of plasma that create a glow.
“We haven’t learned much about black holes themselves yet, but we are able to learn a lot about how they shine,” Philippov said of the study of plasmas surrounding black holes. “Our goal is to understand how all the emission that we see is produced. We can see it, but we cannot really explain why and how, so that’s the underlying question.”
