TY - JOUR AU - Angela Collier AU - Ann-Marie Madigan AB - Resonant torques couple stellar bars to dark matter halos. Here we use high-resolution numerical simulations to demonstrate long-term angular momentum transfer between stellar bars and dark matter orbits of varying orientation. We show that bar-driven reversals of dark matter orbit orientations can play a surprisingly large role in the evolution of the bar pattern speed. In predominantly prograde (corotating) halos, dark matter orbits become trapped in the stellar bar, forming a parallel dark matter bar. This dark matter bar reaches more than double the vertical height of the stellar bar. In halos dominated by retrograde orbits, a dark matter wake forms oriented perpendicular to the stellar bar. These dark matter overdensities provide a novel space to look for dark matter annihilation or decay signals. We predict that the Milky Way hosts a dark matter bar aligned with the stellar bar as well as a dark matter wake, the near side of which should extend from the Galactic center to a galactic longitude of l ≈ 323°. BT - The Astrophysical Journal DA - 2021-06 DO - 10.3847/1538-4357/ac004d IS - 1 N2 - Resonant torques couple stellar bars to dark matter halos. Here we use high-resolution numerical simulations to demonstrate long-term angular momentum transfer between stellar bars and dark matter orbits of varying orientation. We show that bar-driven reversals of dark matter orbit orientations can play a surprisingly large role in the evolution of the bar pattern speed. In predominantly prograde (corotating) halos, dark matter orbits become trapped in the stellar bar, forming a parallel dark matter bar. This dark matter bar reaches more than double the vertical height of the stellar bar. In halos dominated by retrograde orbits, a dark matter wake forms oriented perpendicular to the stellar bar. These dark matter overdensities provide a novel space to look for dark matter annihilation or decay signals. We predict that the Milky Way hosts a dark matter bar aligned with the stellar bar as well as a dark matter wake, the near side of which should extend from the Galactic center to a galactic longitude of l ≈ 323°. PY - 2021 EP - 23 T2 - The Astrophysical Journal TI - The Coupling of Galactic Dark Matter Halos with Stellar Bars UR - https://doi.org/10.3847/1538-4357/ac004d VL - 915 ER -