X-ray Polarization: a Probe of Magnetic Field Geometry in Pulsar Wind Nebulae

by Josephine Wong (Stanford University)

Thursday 5 Feb 2026, 21:40 → 22:00 Asia/Shanghai

Tsung-Dao Lee Institute

Host: Dong Lai
Location: Online
Join Tencent Meeting：https://meeting.tencent.com/dm/iMmsWlsVRwn1
Meeting ID: 613535699 (no password）

Abstract:

Pulsar wind nebulae (PWNe) are fascinating astrophysical sources, the playground of electrons/positrons that have escaped the pulsar magnetosphere along open magnetic fields and are accelerated to ultra-relativistic (up to PeV) energies. These particles emit synchrotron radiation, which is highly polarized, as they gyrate around magnetic fields. And due to their proximity, PWNe are bright and resolvable, making them ideal objects to study with spatially-sensitive X-ray polarization. The Imaging X-ray Polarimetry Explorer (IXPE), launched in December 2021, has to-date observed seven of the brightest PWNe. In this talk, I will present some of my work on using IXPE X-ray polarization to study PWNe, specifically the Crab and MSH 15-52.

Biography:

Josephine Wong is a 6th year astrophysics graduate student at Stanford University. For her dissertation, she has been studying pulsar wind nebulae (PWNe) using X-ray polarization data from the Imaging X-ray Polarimetry Explorer (IXPE), employing a sensitive technique she developed to map nebular field structures and to extract the pulsar polarization to constrain theoretical models. In 2024-25, she was a Pre-Doctoral Fellow at the Harvard-Smithsonian Center for Astrophysics, where she studied the high mass X-ray binary Cygnus X-3. Her research interests lie in Galactic compact objects, working at the intersection of observation and theory to understand the complex physics that govern phenomena such as jet formation, accretion, and relativistic shocks and particle acceleration.