The tangled warp of the Milky Way
Viktor Hrannar J\'onsson, Paul J. McMillan

TL;DR
This study analyzes the Milky Way's warp using Gaia DR3 data, finding it precesses rapidly and is dynamically evolving, challenging existing models of warp formation.
Contribution
It introduces a kinematic model of a precessing warp fitted to Gaia data, revealing the warp's rapid precession and dynamic evolution.
Findings
Warp's line of nodes offset by 40 degrees from Sun
Warp precession speed around 13 km/s/kpc
Including radial velocities worsens model fit
Abstract
We determine the influence of the Milky Way's warp on the kinematics of stars across the disc, and therefore measure its precession rate and line of nodes under different assumptions. We do this by applying Jeans' first equation to a model of a rigidly precessing warp. The predictions of these models are fit to the average vertical velocities of stars with measured line-of-sight velocities in Gaia DR3 data. We test models in which the warp's line of nodes and precession speed are fixed, and models in which they are allowed to vary linearly with radius. We also test models in which the velocity of stars radially in the disc is included in Jeans' equation. The kinematic data is best fit by models with a line of nodes that is 40 degrees offset from the Sun's Galactic azimuth, significantly leading the line of nodes found from the positions of stars. These models have a warp precession…
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