Magnetars as QED Laboratories

Magnetars are the strongest magnets in the universe. Their fields exceed the quantum critical field, where photons split and turn into electron-positron pairs. No laboratory on Earth can reach this regime. Magnetars show a rich phenomenology, from fast radio bursts (e.g., SGR 1935+2154) to persistent X-ray emission that hardens at high energies (e.g., 1E 2259+586) and radio emission after outbursts (e.g., XTE J1810−197). We bring strong-field QED into first-principles plasma simulations to explain these signals. Our simulations show that ions pulled from the stellar surface carry a significant share of the magnetar current. We ask a fundamental question of high-energy astrophysics: How do magnetars shine?

Fast radio bursts and pulsars carry a message from the plasma where they are born. Their polarization and spectra record how radio waves form and escape from extreme magnetospheres. We want to read this message. Fundamental plasma processes are our key tool. Our recent work includes radio wave activation at relativistic magnetized shocks (arXiv), magnetized Kelvin-Helmholtz modes in interacting neutron star magnetospheres (arXiv), radiation drag in photon-rich shocks around cosmic explosions (arXiv), and kink-unstable magnetic columns in magnetized coronae (arXiv). We love sharpening our plasma intuition, because it guides every model we build.

Radio Transients as Plasma Probes

Computational Innovation

First-principles simulations are the backbone of our work. We co-develop the open-source GPU particle-in-cell code Entity, which runs at scale on leadership computing facilities such as Frontier and Perlmutter. Particle-in-cell methods resolve plasma processes on the kinetic scale. High-order force-free and magnetohydrodynamic methods capture the global dynamics of magnetospheres. Together, they let us follow magnetic energy from global eruptions down to the particles that radiate. All our codes are open source, and we turn our results into animations for students and the public.

The Journey

I am an Assistant Professor at the Department of Physics and Astronomy at Dartmouth College. I am also a Visiting Professor and Fellow at the Observatoire de Paris and Université PSL, hosted by LUX at Sorbonne Université. Before that, I was a THEA fellow with Andrei Beloborodov and Lorenzo Sironi at Columbia University, and a postdoc co-supervised by Anatoly Spitkovsky at Princeton University and Alexander Philippov at the Center for Computational Astrophysics (Flatiron Institute). I received a PhD in Physics from the University of Valencia (Spain) under the supervision of Miguel Angel Aloy Toras, and Pablo Cerdá-Durán, and a B.Sc. and M.Sc. in Physics from the Leibniz Universität Hannover (Germany). I received scholarships from the Konrad-Adenauer-Stiftung and the Studienstiftung des Deutschen Volkes, two public foundations that supported my undergraduate and graduate studies in Germany and Spain.

The Extreme Plasmas around Compact Objects EPaCO group at Dartmouth College is always happy to hear from prospective postdocs and graduate students. We love meeting people who are passionate about modeling magnetized plasmas to answer pressing questions in high-energy astrophysics. You can find information about graduate studies at the Department of Physics and Astronomy of Dartmouth College. Also check out our Grad Student Handbook and resources by fellow students.

If you’re interested in joining the group, please email us a description of your research interests, program goals and a CV with contact information for references to start a conversation.

Our group believes in fostering an inclusive space where we can chase our research curiosities and passions. We hope your interests resonate with one or more of the following: plasma astrophysics, compact object magnetospheres, strong-field QED, radio transients, high-energy radiative feedback, numerical method development, big data analysis, and innovative tools for next generation plasma modeling.

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