Discovery and Implications of Vertical Waves in the Galactic Disk



Abstract:

I report on the observation of a Galactic North-South asymmetry in the spatial

distribution of main-sequence stars in the local solar neighborhood, determined

using stars from the Eighth Data Release of the Sloan Digital Sky Survey.

The asymmetry has the appearance of a wave-like perturbation intrinsic to the disk.

I offer evidence in support of the interpretation of the asymmetry as a departure

from gravitational equilibrium in the local solar neighborhood and speculate as to

its possible origins. I outline how future observations can refine the tomography

of local perturbations and consider the implications of such studies for dark-matter

direct detection experiments.