Little time for oscillation: Fast disruption of the Radcliffe Wave by Galactic motions

TL;DR

This study uses data-driven 3D simulations to show that the Radcliffe wave is rapidly stretched and disrupted by Galactic shear and epicyclic motions within 45 million years, challenging previous simplified models.

Contribution

It introduces a comprehensive 3D simulation approach revealing the complex evolution of the Radcliffe wave, highlighting the limitations of earlier simplified models.

Findings

The Radcliffe wave is stretched to nearly twice its length within 45 Myr.

Galactic shear and epicyclic motions significantly influence the wave's evolution.

Formation of new filaments and mergers occurs during the wave's disruption.

Abstract

The Radcliffe wave \cite{2020Natur.578..237A} is a 2.7 kpc long, 100 pc wide-like structure in the Galactic disk with a wave-like velocity structure \cite{2022MNRAS.517L.102L,2024arXiv240212596K}. A referent Nature paper \cite{2024arXiv240212596K} treated the Wave as a solid body in the disk plane, modeled its oscillation along the vertical direction, and derived the local Galactic mass distribution from the oscillation pattern. In reality, Galactic shear can stretch gas through differential rotation, whereas gas clouds experience epicyclic motions. We simulate the 3D evolution of the local interstellar gas and find shear and encyclic motion stretches the Radcliffe wave to almost twice its current length at the timescale of 45 Myr, within which only half a cycle of the proposed vertical oscillation occurs. The simulation also reveals the formation of new filaments and filament-filament mergers. Treating the Radcliffe wave as a solid body in the Galactic disk and an oscillating structure in the vertical direction is thus an oversimplification. Our data-driven simulation reveals the 3D evolution of the local interstellar gas with several processes at play, strengthening the role of the Solar Neighborhood as a unique test ground for theories of interstellar gas evolution.