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Related papers: Delayed phase mixing in the self-gravitating Galac…

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Using Gaia DR3 data, we examine the kinematics of the central core of the Sagittarius (Sgr) dwarf spheroidal galaxy using data which includes proper motions and line-of-sight velocities for member stars in addition to their projected…

Astrophysics of Galaxies · Physics 2025-08-28 Isabelle S. Goldstein , Louis E. Strigari

Stars born on near-circular orbits in spiral galaxies can subsequently migrate to different orbits due to interactions with non-axisymmetric disturbances within the disc such as bars or spiral arms. This paper extends the study of migration…

Astrophysics of Galaxies · Physics 2022-10-05 Christopher Carr , Kathryn V. Johnston , Chervin F. P. Laporte , Melissa K. Ness

We present a new N-body model for the tidal disruption of the Sagittarius (Sgr) dwarf that is capable of simultaneously satisfying the majority of angular position, distance, and radial velocity constraints imposed by current wide-field…

Astrophysics of Galaxies · Physics 2015-05-18 David R. Law , Steven R. Majewski

The Sagittarius dwarf spheroidal (Sgr) is a dissolving galaxy being tidally disrupted by the Milky Way (MW). Its stellar stream still poses serious modelling challenges, which hinders our ability to use it effectively as a probe of the MW…

Astrophysics of Galaxies · Physics 2022-10-12 P. Ramos , T. Antoja , Z. Yuan , A. Arentsen , P. -A. Oria , B. Famaey , R. Ibata , C. Mateu , J. A. Carballo-Bello

What is conducted in the present work is the study of self-gravity effects on vertical structure of magnetized neutrino-dominated accretion disc (termed NDAF and considered as a central engine for Gamma-ray bursts (GRBs)). Some of the disc…

High Energy Astrophysical Phenomena · Physics 2022-01-05 Narjes Shahamat , Shahram Abbassi

The phase spiral is a perturbation to the vertical phase-space distribution of stars in the Milky Way disk. We study the phase spiral's properties and how they vary with spatial position, in order to constrain its origin and evolution, as…

Astrophysics of Galaxies · Physics 2025-07-29 Axel Widmark , Kiyan Tavangar , Josh Kalish , Kathryn V. Johnston , Jason A. S. Hunt

This work explores how assumptions regarding the particle-physics nature of dark matter can alter the evolution of the Sagittarius (Sgr) dwarf spheroidal galaxy and its expansive stellar stream. We run a large suite of $N$-body simulations…

Astrophysics of Galaxies · Physics 2025-03-21 Connor Hainje , Oren Slone , Mariangela Lisanti , Denis Erkal

We present a new method for inferring the gravitational potential of the Galactic disk, using the time-varying structure of a phase-space spiral in the $(z,w)$-plane (where $z$ and $w$ represent vertical position and vertical velocity). Our…

Astrophysics of Galaxies · Physics 2021-11-30 Axel Widmark , Chervin F. P. Laporte , Pablo F. de Salas

We utilize a novel numerical technique to model star formation in cosmological simulations of galaxy formation - called Superstars - to simulate a Milky Way-like galaxy with $\gtrsim10^8$ star particles to study the formation and evolution…

Recent studies using the Gaia DR3 data have revealed a two-armed phase spiral in the $Z-V_Z$ phase space in the inner disk. In this study, we present new features of the two-armed phase spiral revealed by the Gaia Data and a new mechanism…

Astrophysics of Galaxies · Physics 2025-07-03 Junxian Lin , Zhao-Yu Li , Rui Guo , Jason A. S. Hunt , Teresa Antoja , Chengye Cao

We use Gaia DR2 astrometric and line-of-sight velocity information combined with two sets of distances obtained with a Bayesian inference method to study the 3D velocity distribution in the Milky Way disc. We search for variations in all…

The origin of galactic spiral arms is one of fundamental problems in astrophysics. Based on the local analysis Toomre (1981) proposed the swing amplification mechanism in which the self-gravity forms spiral arms as leading waves of stars…

Astrophysics of Galaxies · Physics 2018-09-05 Shugo Michikoshi , Eiichiro Kokubo

A conclusive model for the formation of dwarf spheroidal (dSph) galaxies still remains elusive. Owing to their proximity to the massive spirals Milky Way (MW) and M31, various environmental processes have been invoked to explain their…

Astrophysics of Galaxies · Physics 2017-03-29 Stelios Kazantzidis , Lucio Mayer , Simone Callegari , Massimo Dotti , Leonidas A. Moustakas

The distribution of stars in the Milky Way disc shows a spiral structure--the Snail--in the space of velocity and position normal to the Galactic mid-plane. The Snail appears as straight lines in the vertical frequency--vertical phase plane…

Astrophysics of Galaxies · Physics 2023-04-05 Neige Frankel , Jo Bovy , Scott Tremaine , David W. Hogg

Flow nonnormality induced linear transient phenomena in thin self-gravitating astrophysical discs are studied in the shearing sheet approximation. The considered system includes two modes of perturbations: vortex and (spiral density) wave.…

Astrophysics · Physics 2009-11-13 G. R. Mamatsashvili , G. D. Chagelishvili

We discuss a modification of a recently developed numerical scheme for evolving spherically symmetric self-gravitating systems to include the effects of self-interacting dark matter. The approach is far more efficient than traditional…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-06 Marc Kamionkowski , Kris Sigurdson , Oren Slone

{\it Gaia} Data Release 2 (DR2) revealed that the Milky Way contains significant indications of departures from equilibrium in the form of asymmetric features in the phase space density of stars in the Solar neighborhood. One such feature…

Astrophysics of Galaxies · Physics 2022-07-28 Jason A. S. Hunt , Adrian M. Price-Whelan , Kathryn V. Johnston , Elise Darragh-Ford

Modern studies of the early solar system routinely invoke the possibility of an orbital instability among the giant planets triggered by gravitational interactions between the planets and a massive exterior disk of planetesimals. Previous…

Earth and Planetary Astrophysics · Physics 2019-01-30 Billy Quarles , Nathan Kaib

The Gaia satellite revealed a remarkable spiral pattern ('phase spiral', PS) in the z-Vz phase-plane throughout the solar neighbourhood, where z and Vz are the displacement and velocity of a star perpendicular to the Galactic plane. As…

Astrophysics of Galaxies · Physics 2025-08-21 Thor Tepper-García , Joss Bland-Hawthorn , Timothy R. Bedding , Christoph Federrath , Oscar Agertz

Using observational data, we build numerical N-body, hydrodynamical and combined equilibrium models for the spiral galaxy NGC 5247. The models turn out to be unstable towards spiral structure formation. We simulate scenarios of spiral…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 S. A. Khoperskov , A. V. Khoperskov , I. S. Khrykin , V. I. Korchagin , D. I. Casetti-Dinescu , T. Girard , W. van Altena , D. Maitra