The stellar mass distribution of the Milky Way's bar: an analytic model

TL;DR

This paper introduces an analytic model of the Milky Way's bar stellar mass distribution, fitting a multi-component density to an N-body model to accurately replicate its 3D structure and gravitational potential.

Contribution

The paper provides a detailed analytic model of the Milky Way's bar based on fitting to an N-body simulation, enabling easier use in various dynamical studies.

Findings

Accurately reproduces the 3D density of the Milky Way's bar.

Includes the X-shape structure of the bar.

Provides the gravitational potential for further applications.

Abstract

We present an analytic model of the stellar mass distribution of the Milky Way bar. The model is obtained by fitting a multi-component parametric density distribution to a made-to-measure N-body model of Portail et al., constructed to match a variety of density and kinematics observational data. The analytic model reproduces in detail the 3D density distribution of the N-body bar including the X-shape. The model and the gravitational potential it generates are available as part of the software package AGAMA for galactic dynamics, and can be readily used for orbit integrations, hydrodynamical simulations or other applications.