Space Sciences/Astrophysics Seminar with Riccardo Ferrazzoli on IXPE Observations of Tycho’s Supernova Remnants
Riccardo Ferrazzoli (Hosted by Krawczynski) from National Institute of Astrophysics (INAF), Institute for Space Astrophysics and Planetology (IAPS), will be presenting the seminar "First Results of the IXPE Observations of Tycho’s Supernova Remnants"
Young supernova remnants (SNRs) are among the most important sources of non-thermal X-rays in the sky and are commonly considered to produce most of the Galactic cosmic rays via diffusive shock acceleration. However, there are still many open questions on the physical conditions at their shock fronts, such as the magnetic field orientation and turbulence level. The X-ray synchrotron emission from their shock fronts has been expected to be polarized for some time, with the polarization degree and direction providing unique insights on the turbulence level and morphology of the magnetic field. The NASA/ASI Imaging X-ray Polarimetry Explorer (IXPE), that launched in December 2021, is the first mission entirely dedicated to spatially-resolved X-ray polarimetry. I will present the results of the IXPE observation of Tycho’s SNR, which allowed us to determine its magnetic field topology on sub-parsec scales.
The measured X-ray polarization degree in Tycho is higher than for Cassiopeia A, and higher than what is observed in the radio band, suggesting a more ordered magnetic-field or a larger maximum turbulence scale. The measured tangential polarization direction corresponds to a radial magnetic field, and is consistent with that observed in the radio band. These results are compatible with the expectation of turbulence produced by an anisotropic cascade of a radial magnetic-field near the shock.
Sponsored by the McDonnell Center for the Space Sciences.