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Related papers: Constraining the Milky Way potential using the dyn…

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The gravitational potential of the Milky Way encodes information about the distribution of all matter -- including dark matter -- throughout the Galaxy. Gaia data release 3 has revealed a complex structure that necessitates flexible models…

Astrophysics of Galaxies · Physics 2025-08-05 Taavet Kalda , Gregory M. Green

Selection effects, such as interstellar extinction and varying survey depth, complicate efforts to determine the gravitational potential - and thus the distribution of baryonic and dark matter - throughout the Milky Way galaxy using stellar…

Astrophysics of Galaxies · Physics 2025-12-03 Taavet Kalda , Gregory Green

We present a method to calculate gravitational potential gradients within regions containing few tens of thousands stars with known phase space coordinates. The central idea of the method is to calculate orbital arcs for each star within a…

Astrophysics of Galaxies · Physics 2018-10-10 Rain Kipper , Elmo Tempel , Peeter Tenjes

Bars and spirals are among the main drivers of the secular evolution of galactic disks, and it is, thus, of prime importance to better understand their exact nature and dynamics. In this respect, the Milky Way provides a unique laboratory…

Astrophysics of Galaxies · Physics 2019-08-13 Benoit Famaey , Arnaud Siebert , Ivan Minchev

$Gaia$ DR2 has provided an unprecedented wealth of information about the positions and motions of stars in our Galaxy, and has highlighted the degree of disequilibria in the disc. As we collect data over a wider area of the disc it becomes…

Astrophysics of Galaxies · Physics 2020-07-15 Jason A. S. Hunt , Kathryn V. Johnston , Alex R. Pettitt , Emily C. Cunningham , Daisuke Kawata , David W. Hogg

New constraints on the Milky Way's bar parameters are derived from the gaseous spiral structure within the Galactic bar, and in particular from the identification of the dustlanes leading the bar major axis.

Astrophysics · Physics 2007-05-23 R. Fux

Using numerical analysis of fundamental frequencies we study the orbital structure of a tidally induced bar formed in a simulated dwarf galaxy orbiting a Milky Way-like host. We find that only about 10% of stars have frequencies compatible…

Astrophysics of Galaxies · Physics 2015-11-16 Grzegorz Gajda , Ewa L. Lokas , E. Athanassoula

We present RoadMapping, a full-likelihood dynamical modelling machinery that aims to recover the Milky Way's (MW) gravitational potential from large samples of stars in the Galactic disk. RoadMapping models the observed positions and…

Astrophysics of Galaxies · Physics 2016-10-26 Wilma H. Trick , Jo Bovy , Hans-Walter Rix

The dark matter halo of the Milky Way is expected to be triaxial and filled with substructure. It is hoped that streams or shells of stars produced by tidal disruption of stellar systems will provide precise measures of the gravitational…

Astrophysics of Galaxies · Physics 2015-06-19 Adrian M. Price-Whelan , David W. Hogg , Kathryn V. Johnston , David Hendel

The circular speed curve of the Milky Way provides a key constraint on its mass distribution, reflecting the axisymmetric component of the gravitational potential. This is especially critical in the inner Galaxy ($R \lesssim 4$ kpc), where…

Astrophysics of Galaxies · Physics 2025-07-18 Junichi Baba

RoadMapping is a dynamical modeling machinery developed to constrain the Milky Way's (MW) gravitational potential by simultaneously fitting an axisymmetric parametrized potential and an action-based orbit distribution function (DF) to…

Astrophysics of Galaxies · Physics 2017-04-26 Wilma H. Trick , Jo Bovy , Elena D'Onghia , Hans-Walter Rix

Orbital properties of stars, computed from their six-dimensional phase space measurements and an assumed Galactic potential, are used to understand the structure and evolution of the Galaxy. Stellar actions, computed from orbits, have the…

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.…

Astrophysics of Galaxies · Physics 2020-08-25 Jeffrey M. La Fortune

The evolution of the Milky Way disk, which contains most of the stars in the Galaxy, is affected by several phenomena. For example, the bar and the spiral arms of the Milky Way induce radial migration of stars and can trap or scatter stars…

We develop a method for constraining the potential of the Milky Way using stellar streams with a known progenitor. The method expresses the stream in angle-action coordinates and integrates the orbits of the stars backwards in time to…

Astrophysics of Galaxies · Physics 2025-11-10 C. G. Palau , W. Wang , J. Han

Action-based dynamical modelling, using stars as dynamical tracers, is an excellent diagnostic to estimate the underlying axisymmetric matter distribution of the Milky Way. However, the Milky Way's bar causes non-axisymmetric resonance…

Astrophysics of Galaxies · Physics 2023-06-27 Soumavo Ghosh , Wilma H. Trick , Gregory M. Green

Galactic archaeologists often assume that integrals of motion (IoMs) such as $L_z$ and $E$ are conserved, so substructure remains frozen in IoM space over many Gyr. However, this is not true in the Milky Way due in part to its rotating bar.…

Astrophysics of Galaxies · Physics 2025-09-03 Adam M. Dillamore , Jason L. Sanders

We quantify how bar-driven non-circular motions bias Milky-Way gas maps inferred with the kinematic-distance (KD) method. KD reconstructions of H\,\textsc{i} and CO surveys assume circular rotation in an axisymmetric potential, an…

Astrophysics of Galaxies · Physics 2026-02-05 Junichi Baba

Obtaining reliable distance estimates to gas clouds within the Milky Way is challenging in the absence of certain tracers. The kinematic distance approach has been used as an alternative, derived from the assumption of circular trajectories…

A bar-like central feature is commonly observed in both nearby and distant spiral-type galaxies, including the Milky Way. While many methods exist to categorise this morphology, no one method has emerged as the field-wide standard. To…

Astrophysics of Galaxies · Physics 2026-04-22 Elizabeth J. Iles , Finn A. Pal , Joss Bland-Hawthorn , Ken Freeman