Sasha Philippov Investigates Plasma Around Black Holes and Neutron Stars

Curiosity about the cosmos has attracted many young astrophysicists to their careers, but that was not the case for Alexander “Sasha” Philippov. While growing up in Russia, he was a natural at science and even competed in the national Physics Olympiad for high school students. However, his interests at the time were more down-to-earth.Sasha PhilippovSasha Philippov

“I was not into astrophysics whatsoever,” said Philippov, who joined the University of Maryland’s Department of Physics as an assistant professor in May 2022. “When I went to college, I was hoping to do theoretical particle physics, but my advisor and mentor, Professor Vasily Beskin, showed me that you can do very interesting, detailed modeling in astrophysics. It looked like real physics to me—not just looking into a telescope and watching the stars.”
Philippov has been starstruck ever since, using a combination of theory and computer modeling to tackle big questions in high-energy astrophysics and publish over 60 papers. 

After completing his undergraduate studies at the Moscow Institute of Physics and Technology, he earned a Ph.D. in astrophysical sciences from Princeton University in 2017. It was during his graduate studies that he started specializing in the physics of plasmas—a state of matter comprising hot, ionized gas that surrounds “some of the most mysterious and exotic objects in the universe,” including black holes and neutron stars, Philippov said. 

He was then named a NASA Einstein and Theoretical Astrophysics Center Fellow and completed his postdoc at UC Berkeley, where he co-developed computer code to model the behavior of charged particles around rotating black holes.

“This sort of thing had never been modeled before, because you need to take into account the effects of general relativity, how the electromagnetic fields are modified by the spinning black hole and how they react to the dynamics of charged particles,” Philippov explained. “Ours was the first code that could do it.” 

His code enabled a flurry of studies—including five publications in the journal Physical Review Letters—which offered new insights into the extraction of energy from rotating black holes, the production of electron-positron plasmas and electromagnetic flares near the event horizons of black holes, and the accretion of collisionless plasma.

After his postdoc, Philippov worked as an associate research scientist at the Simons Foundation’s Flatiron Institute in New York City, where he continued to study the emission mechanisms of pulsars—magnetized neutron stars that rapidly rotate. During this time, he constructed the first models capable of explaining the mysterious coherent emission of pulsars, which were found to produce relativistic lightning strong enough to shoot beams of radio waves out into space. Although this cosmic phenomenon was discovered more than 50 years ago, its cause was not fully understood until Philippov’s study.

Recently, he was named deputy director of a multi-institutional Simons Foundation project called the Simons Collaboration on Extreme Electrodynamics of Compact Sources (SCEECS). The team will model electrodynamic processes related to neutron stars and black holes, which have magnetic fields that are 10 billion times stronger than those associated with the Large Hadron Collider in Switzerland.

The group will use kinetic plasma simulations and large-scale fluid-type modeling to study the underlying emission mechanisms of magnetars—neutron stars with the strongest magnetic fields—and spinning black holes. Advances in high-performance computing and telescope technologies help make this work possible.

“It’s a big investment for research that is completely theoretical,” Philippov said of the grant. “We will be looking at a collection of both completely new and very old problems—the latter having been revitalized by the power of computer simulations and new observations. It’s a great time to do this.”

Philippov also recently received a $600,000 grant from the National Science Foundation to support the modeling of phenomena in extreme plasmas around black holes and neutron stars. In addition, he continues to study the radiation of neutron stars (including enigmatic fast radio bursts), flares from accreting supermassive black holes and merging neutron stars, and particle acceleration in jets produced by black holes. 

As a Fellow in the Joint Space-Science Institute (JSI), a collaboration between the NASA’s Goddard Space Flight Center and UMD’s astronomy and physics departments, Philippov is helping to organize a workshop in October 2023 that will share the latest expertise on “winds throughout the universe,” including everything from the sun’s powerful wind to the gusts produced by merging neutron stars.

In his day-to-day work, Philippov works closely with students and postdoctoral fellows and said he “tremendously enjoys mentoring and interacting with early career researchers.” 

Though he was not instantly smitten with astrophysics as a high school student, he is happy he pursued this career path. For him, having the chance to ponder big questions in astrophysics—and better yet, to answer them—is what continues to drive his research.

“The time that you get to study something completely new is why we are in this business,” Philippov said. “The joy of getting to finally understand something after a long time is remarkable.”


Written by Emily Nunez.

In Memoriam

It is with much sadness that the Department of Physics announces the passing of several members of our community.

  • Donald Robert Benton (Ph.D., '85) died on May 5, 2023.
  • Larry Lambert Burton (Ph.D., '77) died on March 23, 2023.
  • Richard Durkin (M.S., '72) died on April 22, 2023. 
  • Lewis Fulcher, a former postdoctoral associate, died on May 9, 2023.
  • Professor Emeritus Charles William Misner died on July 24, 2023. A memorial service is planned for November 10 & 11More
  • Sherman Poultney, a faculty member who worked on the Lunar Laser Ranging Reflector for Apollo 11, died on February 9, 2023.
  • Bruce Rowley, a talented machinist in the Department of Physics from 2004 until his retirement in 2022,, died on July 19.
  • Arthur W. Ruff (Ph.D., '64), died on April 24, 2023.
  • Philip DiLavore III, a who served as an Assistant Professsor before moving to Indiana State University in 1971, on died July 16, 2023.
  • Jonathan San Miguel (B.S., '17), died on April 16, 2023, in Stanford, CA.

Faculty, Staff, Student and Alumni Awards & Notes

We proudly recognize members of our community who recently garnered major honors, began new positions and more.

Faculty and Staff 
Department News

The department was ranked highly by US News.

The JQI released a new podcast.

Buonanno Elected to Italian National Academy of Sciences

Alessandra Buonanno has been elected a member of the Accademia Nazionale dei Lincei, the Italian National Academy of Sciences

Buonanno is the director of the Astrophysical and Cosmological Relativity Department at the Max Planck Institute for Gravitational Physics  (Albert Einstein Institute) in Potsdam and a Research Professor at the University of Maryland.

Buonanno's research has spanned several topics in gravitational wave theory, data analysis and cosmology. She is a Principal Investigator of the LIGO Scientific Collaboration, and her waveform modeling of cosmological events has been crucial in the experiment’s many successes. Her work has merited election to the U.S. National Academy of Sciences and Leopoldina, the German National Academy of Sciences.

In 2018, Buonanno received the Leibniz Prize, Germany's prestigious research award. Other accolades include the Galileo Galilei Medal of the National Institute for Nuclear Physics (INFN), the Tomalla Prize, the Dirac Medal (with Thibault Damour, Frans Pretorius, and Saul Teukolsky) and the Balzan Prize (with Damour).

Alessandra Buonanno © A. Klaer Alessandra Buonanno © A. Klaer

She is a Fellow of the American Physical Society and the International Society of General Relativity and Gravitation and a recipient of the Alfred P. Sloan Foundation Fellowship and the Richard A. Ferrell Distinguished Faculty Fellowship.

Buonanno, Charlie Misner, Peter Shawhan and others detailed UMD's contributions to gravitational studies in a 2016 forum, A Celebration of Gravitational Waves


UMD Lab to Become Major Laser Research Center

Led by Professor Howard Milchberg, the Lab for Intense Laser-Matter Interactions has been chosen as one of ten LaserNetUS nodes.  The lab will receive an annual award for three years to fund laser lab research staff, postdocs and graduate students.

LaserNetUS was established in 2018 by the US Department of Energy (DOE) and is funded through the DOE’s Office of Fusion Energy Sciences (FES).  The purpose of the network is to allow US and international researchers without access to high powered and unique lasers the ability to  do experiments in cooperation with the network’s facilities.  In return, this leads to the advancement of research and  stimulates collaboration between various research groups.Professor Milchberg's Laser Matter Interactions GroupProfessor Milchberg's Laser Matter Interactions Group

This year, UMD is one of three new nodes.  As a collaborative node, Milchberg’s lab will accept proposals from other research groups and will have the opportunity to collaborate with those that best fit its scientific agenda.

Milchberg notes that ”this award recognizes our lab’s broad array of laser sources and techniques and its commitment to fundamental physics understanding and student education. This has been the recipe for many well-known Maryland innovations and discoveries” 

Read here for more information on LaserNetUS. 


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