New Views From Galactoseismology: Rethinking the Galactic Disk-Halo Connection

We present preliminary results from a study exploring the origin of Milky Way substructures, and show initial evidence of a common ``kicked- out'' formation mechanism for two low-latitude substructures. In this scenario, stars in these substructures formed in the disk and were subsequently ``kicked-out'' by an external perturbation, such as the merger of an accreted satellite, which created an oscillation in the Galactic disk. To test this origin scenario, we found the fraction of different stellar populations - M giants and RR Lyrae stars - in the Monoceros Ring (also known as GASS) and A13, supplementing a study of stellar populations in the Triangulum-Andromeda cloud. This work provides: (1) the first analysis of the GASS and A13 features based upon their stellar populations; and (2) preliminary evidence of disk stars in the Milky Way that have been relocated to the disk-halo interface due to vertical oscillations of the Milky Way's disk