Evidence of gradients of density and magnetic field in the remnant of Tycho's supernova

TL;DR

This study maps the density and magnetic field gradients in Tycho's supernova remnant using radio and X-ray data, revealing spatial variations that inform the understanding of particle acceleration and gamma-ray emission.

Contribution

It provides the first detailed spatial distribution of post-shock density and magnetic field strength in Tycho's SNR based on multi-wavelength surface brightness analysis.

Findings

Density gradient towards the north-west

Magnetic field aligned with the Galactic plane

Derived electron energy distribution parameters

Abstract

By using surface brightness maps of Tycho's supernova remnant (SNR) in radio and X-rays, along with the properties of thermal and synchrotron emission, we have derived the post-shock density and magnetic field strength distributions over the projection of this remnant. Our analysis reveals a density gradient oriented towards the north-west, while the magnetic field strength gradient aligns with the Galactic plane, pointing eastward. Additionally, utilizing this magnetic field map, we have derived the spatial distributions of the cut-off frequency and maximum energy of electrons in Tycho's SNR. We further comment on the implications of these findings for interpreting the gamma-ray emission from Tycho's SNR.