Supernova-remnant origin of the Galactic-Centre filaments

TL;DR

This paper proposes that the Galactic-Centre filaments are relics of supernova remnants driven by past supernovae in the central molecular zone, explaining their morphology, spectrum, and plasma heating.

Contribution

It introduces a supernova remnant model for the origin of the Galactic-Centre filaments, supported by MHD wave simulations and observational consistency.

Findings

GCFs are explained by relic supernova remnants from past SNe in the CMZ.

The model reproduces the morphology and non-thermal spectrum of GCFs.

The SNR model accounts for plasma heating and brightness distribution.

Abstract

The mechanism to produce the numerous Galactic-Centre filaments (GCF) that vertically penetrate the Galactic plane without clear evidence of connection to the disc remains a mystery . Here we show that the GCFs are explained by relics of supernova remnants (rSNR) driven by hundreds of supernovae (SNe) exploded in the star-forming ring of the central molecular zone (CMZ) at an SN rate of $\sim 2\times 10^{-4}$ y$^{-1}$ in the past $\sim 0.5$ My. The evolution of rSNRs is simulated by the propagation of fast-mode magneto-hydrodynamic (MHD) waves, which are shown to converge around the Galactic rotation axis by the focusing effect. Tangential projection of the cylindrical wave fronts on the sky constitutes the vertical filaments. The SNR model explains not only the morphology, but also the non-thermal radio spectrum, smoothed brightness over the distribution area consistent with the $\Sigma-D$ relation of SNR,and the heating mechanism of hot plasma in the GC. We also discuss the implication of the model on the study of the interstellar physics and star-formation activity in the Galactic Centre.