A Physical Interpretation of Milky Way Galaxy Dynamics from Precision Astrometrics

TL;DR

This paper uses high-precision stellar data to analyze the Milky Way's dynamics, revealing a compact structure with features challenging the traditional dark matter halo model and providing insights into galaxy mass discrepancies.

Contribution

It offers a new physical interpretation of Milky Way dynamics based on precise kinematic data, challenging existing dark matter halo assumptions.

Findings

Milky Way is a highly compact, thermalized object.

Significant velocity-spatial substructure observed.

Keplerian signatures contradict extended dark matter halo models.

Abstract

The dynamical and virial mass of the Milky Way galaxy is estimated using latest high precision stellar halo and dwarf galaxy satellite kinematics. The new data suggest the Galaxy is a highly compact, classically thermalized object. Kinematics exhibit significant velocity-spatial substructure, distinctive dynamic partitions, and strong Keplerian signatures that run counter to popular notions of featureless and massively extended dark matter halos. The effective local escape velocity profile of the Galaxy is quantified in terms of distribution and kinematics to reveal the physics responsible for the Mass Discrepancy-Acceleration (MDAR) and Radial Acceleration (RAR) relations.