More than just a wrinkle: A wave-like pattern in radial velocity vs. angular momentum from Gaia Data

Understand

We present a newly found wave--like pattern in mean Galactocentric radial velocity U_g vs.

• guiding centre radius R_g or angular momentum L_z of stars in the RV subsample of Gaia DR2.
• The short-wave pattern has a wavelength of order 1.2 kpc in R_g or 285 kpc km/s in L_z.
• The pattern shows only weak changes with Galactocentric radius R and little change in strength in particular with the vertical energy E_z of the stars or respectively the distance to the Galactic plane |z|.