Three-dimensional velocity fields in the silicon- and sulfur-reach ejecta in the remnant of Tycho supernova

TL;DR

This study reconstructs the three-dimensional velocity structure of silicon- and sulfur-rich ejecta in the Tycho supernova remnant using X-ray and radio observations, revealing asymmetries and velocity differences that inform supernova explosion models.

Contribution

It provides the first detailed 3D velocity map of ejecta in Tycho's remnant, combining spectral and proper motion data to analyze asymmetries and internal structure.

Findings

Velocity differences of thousands of km/s across the remnant

20-30% variation in ejecta speeds on opposite sides

Higher isotropy in silicon ejecta compared to sulfur

Abstract

The three-dimensional velocity structure of the shock-heated Si-reach and S-reach ejecta were reconstructed in Tycho supernova remnant from Doppler-shifted lines. The vector components along the line of sight were restored from the spatially resolved spectral analysis of the Doppler shifts of Si XIII and S XV lines. The components in the plane of the sky were derived from analysis of the proper motion of the remnant's edge at different azimuths. This has been done by using the data of X-ray observations from Chandra observatory as well as the radio data from the Very Large Array. Differences in Doppler velocities over the Tycho's SNR are of the order of thousands of km/s. The speed of the ejecta on the opposite sides of the remnant as a three-dimensional object differs on 20-30%. There are asymmetries and differences in the spatial distributions between the Si-reach and S-reach ejecta components. Namely, the level of isotropy is higher in Si while the vector components directed outward of the observer are larger in S. This puts limitations on the level of deviation of the internal structure of the progenitor star from the ideal layered structure as well as on the level of asymmetries in supernova explosion.