Detection of High-Velocity Na$\;$I Absorption Toward the Stellar Remnant of SN 1181 AD

TL;DR

This paper reports the detection of weak high-velocity Na I absorption in the spectrum of the stellar remnant of SN 1181 AD, indicating complex kinematic features not matching the remnant's optical expansion velocity.

Contribution

First detection of high-velocity Na I absorption toward the remnant of SN 1181 AD, providing new insights into its kinematic structure.

Findings

Detected Na I absorption at -61 km/s in the remnant's spectrum.

Absorption velocity is similar to older supernova remnants but much less than the optical nebula.

Discussed possible origins and nature of the high-velocity absorption.

Abstract

We report the detection of weak high-velocity Na$\;$I absorption at V$_{\odot}$ = $-61.0\pm0.2$ km s$^{-1}$ in the spectrum of the stellar remnant at the center of the Galactic supernova remnant of 1181 AD. This velocity is not unlike that seen in old, more evolved SN remnants, but is much less than the remnant's $\simeq10^{3}$ km s$^{-1}$ expanding optical nebula. We briefly discuss its possible nature and origin.