Speaker
Description
Young supernova remnants (SNRs) are natural laboratories where collision-less shock physics, magnetic-field amplification, and particle acceleration operate under plasma conditions inaccessible on Earth.
Thanks to imaging X-ray polarimetry, IXPE provides, for the first time, a direct probe of the magnetic-field geometry and turbulence level within the narrow synchrotron rims that trace the highest-energy electrons, thereby sampling the plasma conditions at the particle-acceleration sites.
IXPE observations of Cas A, Tycho, SN 1006, RX J1713.7−3946, and Vela Jr. reveal systematically measurable X-ray polarization degrees and orientations, varying with shock speed, ambient density, and magnetic-field strength.
These results establish a tight link between observables—polarization degree and angle, as well as spatial scales—and plasma processes behind particle acceleration such as Bell instability growth, turbulent cascades, and magnetic-field re-orientation across the shock.
We summarize the empirical IXPE constraints and discuss how polarimetric diagnostics is fundamental in the context of particle acceleration (turbulence spectrum, coherence length, Bohm factor, and post-shock magnetic-field amplification) that is becoming most complex, most data we collect.
