Xianhuan Lei | Searcharxiv

arXiv2026

A Study Revealing Physical Attributes of Supernova Remnant in G321.3-3.9

We present a radio analysis of the recently identified supernova remnant G321.3-3.9 using archival multi-wavelength data spanning 88-2304 MHz. The source exhibits an elliptical shell-like morphology (1.3 deg x 1.7 deg) and a relatively flat non-thermal spectral index of alpha = -0.40 +/- 0.03. The distance is estimated using both the Sigma-D relation (1.6-2.9 kpc) and tentative associations with HI structures, the latter suggesting a near-side solution of 2.5-3.3 kpc, though the physical connection remains uncertain.

astro-ph.GA↗

arXiv2022

A Study of Radio Knots within Supernova Remnant Cassiopeia A

The study on the dynamic evolution of young supernova remnants (SNRs) is an important way to understand the density structure of the progenitor's circumstellar medium. We have reported the acceleration or deceleration, proper motion and brightness changes of 260 compact radio features in the second youngest known SNR Cas A at 5\,GHz based on the VLA data of five epochs from 1987 to 2004. The radio expansion center locates at $α(1950)=23^{\rm h}21^{\rm m}9^{\rm s}_{\cdot}7 \pm 0^{\rm s}_{\cdot}29, δ(1950)=+58^{\circ}32^{\prime}25^{\prime\prime}_{\cdot}2 \pm 2^{\prime\prime}_{\cdot}2$. Three-quarters of the compact knots are decelerating, this suggests that there are significant density fluctuations in the stellar winds of the remnant's progenitor. We have verified that the acceleration or deceleration of compact knots are not related with the distribution of brightness. The brightening, fading, disappearing or new appearing of compact radio features in Cas A suggests that the magnetic field in the remnant is changing rapidly.

astro-ph.GA↗