Discovery of a coherent, wave-like velocity pattern for the Radcliffe wave

ABSTRACT Recent studies discovered that part of the Gould Belt belongs to a 2.7 kpc-long coherent, thin wave consisting chain clouds, where damped undulation pattern has been identified from spatial arrangement clouds. We use proper motions young stellar objects anchored inside clouds study kinematic structure Radcliffe in terms vz, and identify damped, wave-like vz space, which we call ‘velocity undulation’. propose new formalism based on ensemble empirical mode decomposition determine amplitude, period, phase pattern, find velocity share an almost identical frequency about 1.5 kpc, both are when measured one side other. Measured for first cycle, they exhibit difference around 2π/3. The is oscillating mid-plane Milky Way disc with amplitude ${\sim}130\, \pm \, 20\, \rm pc$. vertical extent exceeds thickness molecular disc, suggesting signature might originate perturbation, e.g. passage dwarf galaxy.