The Interaction of a Supernova Remnant with background interstellar turbulence

TL;DR

This study investigates how supernova remnants interact with turbulent interstellar magnetic fields using MHD simulations, analyzing turbulence characteristics and comparing results with X-ray observations of SN 1006.

Contribution

It introduces a novel analysis method for turbulence using autocorrelation and structure functions, and explores the impact of density and magnetic fluctuations on SNR evolution.

Findings

Identified turbulence correlation lengths in SNR environments.

Demonstrated the effect of magnetic field fluctuations on shock morphology.

Provided preliminary comparison with observational data of SN 1006.

Abstract

Supernova explosions (SNe) are among the most energetic events in the Universe. After the explosion, the material ejected by the Supernova expands throughout the interstellar medium (ISM) forming what is called Supernova Remnant (SNR). Shocks associated with the expanding SNR are sources of galactic cosmic rays, that can reach energy of the PeV order. In these processes, a key role is played by the magnetic field. It is known that the ISM is turbulent with an observed magnetic field of about a few $\mu$G, made by the superposition of a uniform and a fluctuating component. During the SNR expansion, the shock interacts with a turbulent environment, leading to a distortion of the shock front and a compression of the medium. In this work, we use the MagnetoHydroDynamics (MHD) PLUTO code to mimic the evolution of the blast wave associated with the SNR. We make a parametric study varying the level of density and magnetic field fluctuations in the interstellar medium, with the aim of understanding the best parameter values able to reproduce real observations. We introduce a novel analysis technique based on two-dimensional autocorrelation function $C({\ell})$ and the second order structure function $S_2(\ell)$, quantifying the level of anisotropy and the turbulence correlation lengths. By interpolating the autocorrelation function on a polar grid, we extract the power spectra of turbulence at the SNR. Finally, a preliminary comparison with Chandra observations of SN 1006 is also presented.