Speaker
Description
Supernovae explosions (SNe) are among the most energetic events in
the Universe. They represent an instantaneous release of energy of about 10$^{51}$ erg, associated to the catastrophic collapse of a massive star or to a runaway nuclear burning on the surface of a white dwarf. Following the explosion, the ejected material expands into the interstellar medium (ISM), forming a Supernova Remnant (SNR).
Shocks generated by expanding SNRs are widely recognized as the main
sources of Galactic cosmic rays, which can reach energies up to the PeV
order. In these processes a key role is played by the magnetic field. The ISM
is turbulent, characterized by a magnetic field of about $\mu$G with
a uniform component and a fluctuating one. During its expansion the SNR
shock interacts with a turbulent environment and, as a consequence, the
surface of the shock can be distorted and the level of fluctuations
increase. Understanding these high-energy shocks is also important for studying the behavior of shocks within the heliosphere and the physics of particles at shocks.
We use the MHD PLUTO code in order to mimic the evolution of the blast
wave associated to the SNR into a (compressible) turbulent ISM. We perform a parametric study by varying the level of density and magnetic fluctuations, aiming to identify the best parameter values able to reproduce observations.
We introduce a novel analysis technique based on a two-dimensional
autocorrelation function C(ℓ) and on a second-order structure function S$_2$(ℓ),
which quantify the level of turbulent anisotropy and the correlation lengths.
By interpolating the autocorrelation function on a polar grid, we extract the
turbulent power spectra at the SNR shock. Finally, we present a preliminary
comparison with Chandra X-ray observations of SN 1006.
This work is supported by the Space It Up project funded by the Italian Space Agency, ASI, and the Ministry of University and Research, MUR, under Contract No. 2024-5-E.0 - CUP No. I53D24000060005.
