Two years of supernova remnants with IXPE

Launched December 9, 2021, The Imaging X-ray Polarimetry Explorer (IXPE) has already observed statistically significant polarization from 3 supernova remnants (SNR) in the 2-8 keV band. The older and already published sample of three young SNR namely Cas A, Tycho’s SNR and SN1006, all exhibited radial magnetic fields and a high degree of turbulence. While a high degree of turbulence is expected, the radial magnetic field, which was already puzzling for radio observations is even more surprising for X-ray data. Indeed, the synchrotron radiated photons seen in X-rays trace the status of freshly accelerated plasma which is not necessarily influenced in the same way by hydrodynamic instabilities as these are further downstream of the shock, where they radiate in radio waves. While generally the measured low degree of polarization is consistent with expectations, we also found a trend with other parameters such as ambient density, chronological age and Bohm factor. We will report on the results of these studies as well as on new observations of RX J1713.7-3946 and RCW 86.