Warped Disk Galaxies. II. From the Cosmic Web to the Galactic Warp

Abstract

Galactic warps are common in disk galaxies. While often attributed to galaxy--galaxy tides, a non-spherical dark matter (DM) halo has also been proposed as a driver of disk warping. We investigate links among warp morphology, satellite distribution, and large-scale structure using the Sloan Digital Sky Survey catalog of warped disks compiled by Zee et al.\ (2022). Warps are classified into 244 S and 127 U types, hosting 1,373 and 740 satellites, respectively, and are compared to an unwarped control matched in stellar mass, redshift, and local density. As an indirect, population-level proxy for the host halo's shape and orientation, we analyze the stacked spatial distribution of satellites. Warped hosts show a significant anisotropy: an excess at $45^{\circ}<\phi<90^{\circ}$ (measured from the host major axis), peaking at $P(\phi)\simeq 0.003$, versus nearly isotropic controls. Satellites of S-type warps preferentially align with the nearest cosmic filament, whereas those of U-type warps are more often perpendicular. The incidence of warps increases toward filaments ($r_{\rm fil}<4,{\rm Mpc},h^{-1}$), while the number of satellites around warped hosts remains approximately constant with filament distance, indicating a direct influence of the large-scale environment. We discuss possible links between galactic warps and the cosmic web, including anisotropic tidal fields and differences in evolutionary stage.