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Related papers: Dynamical streams in the local stellar halo

200 papers

Dark matter sub-halos that pass near or through a thin tidal star stream locally increase its velocity dispersion. Subsequent orbital evolution further increases the velocity dispersion and stream width, lowering the surface density of a…

Astrophysics of Galaxies · Physics 2023-07-06 Raymond G. Carlberg , Hayley Agler

We explore the vicinity of the Milky Way through the use of spectro-photometric data from the Sloan Digital Sky Survey and high-quality proper motions derived from multi-epoch positions extracted from the Guide Star Catalogue II database.…

Astrophysics of Galaxies · Physics 2015-10-07 Paola Re Fiorentin , Mario G. Lattanzi , Alessandro Spagna , Anna Curir

Recent observations have revealed a trove of unexpected morphological features in many of the Milky Way's stellar streams. Explanations for such features include time-dependent deformations of the Galactic gravitational potential, local…

Astrophysics of Galaxies · Physics 2022-12-22 Tomer D. Yavetz , Kathryn V. Johnston , Sarah Pearson , Adrian M. Price-Whelan , Chris Hamilton

The length and pattern speed of the Milky Way bar are still controversial. Photometric and spectroscopic surveys of the inner Galaxy, as well as gas kinematics, favour a long and slowly rotating bar, with corotation around a Galactocentric…

Astrophysics of Galaxies · Physics 2017-01-18 Giacomo Monari , Daisuke Kawata , Jason A. S. Hunt , Benoit Famaey

Stellar streams retain a memory of their gravitational interactions with small-scale perturbations. While perturbative models for streams have been formulated in action-angle coordinates, a direct transformation to these coordinates is only…

Several long, dynamically cold stellar streams have been observed around the Milky Way Galaxy, presumably formed from the tidal disruption of globular clusters. In integrable potentials---where all orbits are regular---tidal debris…

Stellar streams result from the tidal disruption of satellites and star clusters as they orbit a host galaxy, and can be very sensitive probes of the gravitational potential of the host system. We select and study narrow stellar streams…

Astrophysics of Galaxies · Physics 2017-03-08 Robyn E. Sanderson , Johanna Hartke , Amina Helmi

To place the highly substructured stellar halos of the Milky Way and M31 in a larger context of hierarchical galaxy formation, it is necessary to understand the prevalence and properties of tidal substructure around external galaxies. This…

Astrophysics of Galaxies · Physics 2016-03-23 Jeffrey L. Carlin , Rachael L. Beaton , David Martinez-Delgado , R. Jay Gabany

Stellar streams from disrupted globular clusters are excellent probes of dark matter (DM) subhalos. Observed Milky Way streams display a remarkable diversity of features: spurs, gaps, kinks, cocoons, and density variations, many attributed…

We studied 12 disk streams found in a 250$^3$ pc$^3$ volume in the solar neighborhood, which we define as coeval and comoving stellar structures with aspect ratios greater than 3:1. Using Gaia Data Release 3 data and the advanced clustering…

Astrophysics of Galaxies · Physics 2025-09-11 Sebastian Ratzenböck , João Alves , Emily L. Hunt , Núria Miret-Roig , Stefan Meingast , Torsten Möller

We study the formation of the Milky Way's halo in a $\Lambda$CDM cosmology by scaling down a high resolution simulation of the formation of a cluster of galaxies. We determine how much phase-space substructure is left over from the objects…

Astrophysics · Physics 2009-09-25 Amina Helmi , Simon D. M. White , Volker Springel

Local stellar motions are expected, and have been shown, to include signatures of the Galaxy's past dynamical evolution. These are typically divided into the disc, which shows the dynamical effects of spiral arms and the bar, and the…

Astrophysics of Galaxies · Physics 2022-12-26 Daniel Mikkola , Paul J. McMillan , David Hobbs

Identifying the structure of our Galaxy has always been fraught with difficulties, and while modern surveys continue to make progress building a map of the Milky Way, there is still much to understand. The arm and bar features are important…

Astrophysics of Galaxies · Physics 2020-01-08 Alex R. Pettitt , Sarah E. Ragan , Martin C. Smith

We analyse the dynamical properties of substructures in a high-resolution dark matter simulation of the formation of a Milky Way-like halo in a $\Lambda$CDM cosmology. Our goal is to shed light on the dynamical peculiarities of the Milky…

Astrophysics · Physics 2008-03-11 Yang-Shyang Li , Amina Helmi

We describe a technique that finds orbits through the Galaxy that are consistent with measurements of a tidal stream, taking into account the extent that tidal streams do not precisely delineate orbits. We show that if accurate…

Astrophysics of Galaxies · Physics 2010-03-01 Andy Eyre , James Binney

We present a model for the interaction of the GD-1 stellar stream with a massive perturber that naturally explains many of the observed stream features, including a gap and an off-stream spur of stars. The model involves an impulse by a…

Astrophysics of Galaxies · Physics 2019-07-31 Ana Bonaca , David W. Hogg , Adrian M. Price-Whelan , Charlie Conroy

Both the three-dimensional density of red clump giants and the gas kinematics in the inner Galaxy indicate that the pattern speed of the Galactic bar could be much lower than previously estimated. Here, we show that such slow bar models are…

Astrophysics of Galaxies · Physics 2016-12-21 Giacomo Monari , Benoit Famaey , Arnaud Siebert , Aurore Duchateau , Thibault Lorscheider , Olivier Bienaymé

We run N-body smoothed particle hydrodynamics (SPH) simulations of a Milky Way sized galaxy. The code takes into account hydrodynamics, self-gravity, star formation, supernova and stellar wind feedback, radiative cooling and metal…

Astrophysics of Galaxies · Physics 2015-06-04 Robert J. J. Grand , Daisuke Kawata , Mark Cropper

The halo of the Milky Way galaxy hosts multiple dynamically coherent substructures known as stellar streams that are remnants of tidally disrupted systems such as globular clusters (GCs) and dwarf galaxies (DGs). A particular case is that…

Tidal streams of disrupted clusters are routinely detected in the halo of the Milky Way. It was recently shown that tidal streams of open clusters can now also be detected within the disc. In this work, we highlight the fact that tidal…