The mechanics of tidal streams

Abstract

We present an analysis of the mechanics of thin streams, which are formed following the tidal disruption of cold, low-mass clusters in the potential of a massive host galaxy. The analysis makes extensive use of action-angle variables, in which the physics of stream formation and evolution is expressed in a particularly simple form. We demonstrate the formation of streams by considering examples in both spherical and flattened potentials, and we find that the action-space structures formed in each take on a consistent and characteristic shape. We demonstrate that tidal streams formed in realistic galaxy potentials are poorly represented by single orbits, contrary to what is often assumed. We further demonstrate that attempting to constrain the parameters of the Galactic potential by fitting orbits to such streams can lead to significant systematic error. However, we show that it is possible to predict accurately the track of streams from simple models of the action-space distribution of the disrupted cluster.

23 pages, 20 figures, to appear in MNRAS. Minor revisions in response to a referee; missing factor 2 added to eq (33) and following equations resulting in minor changes in results

References in corpus (29)

• The Sloan Digital Sky Survey: Technical Summary
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: I. Morphology of the Sagittarius Core and Tidal Arms
• The Field of Streams: Sagittarius and its Siblings
• Building up the Stellar Halo of the Galaxy
• A Low Latitude Halo Stream around the Milky Way
• Constraining the Milky Way potential with a 6-D phase-space map of the GD-1 stellar stream
• Detection of a 63 Degree Cold Stellar Stream in the Sloan Digital Sky Survey
• The extended tails of Palomar 5: A ten degree arc of globular cluster tidal debris
• Fossil Signatures of Ancient Accretion Events in the Halo
• An Orphan in the "Field of Streams"
• Four New Stellar Debris Streams in the Galactic Halo
• The Origin of the Bifurcation in the Sagittarius Stream
• Detection of a 60 Degree-Long Dwarf Galaxy Debris Stream
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: III. Constraints on the Flattening of the Galactic Halo
• Modeling the disruption of the globular cluster Pal5 by Galactic tides
• Detection of a 45 Degree Tidal Stream Associated with the Globular Cluster NGC 5466
• Discovery of a New, Polar-Orbiting Debris Stream in the Milky Way Stellar Halo
• Re-Assembling the Sagittarius Dwarf Galaxy
• The Orbit of the Orphan Stream
• The geometry of phase mixing
• Disassembling the Galaxy with angle-action coordinates
• The case for OH suppression at near-infrared wavelengths
• Tidal tails around globular clusters. Are they a good tracer of cluster orbits?
• An Orbit Fit for the Grillmair Dionatos Cold Stellar Stream
• GRB 060418 and 060607A: the medium surrounding the progenitor and the weak reverse shock emission
• The dynamics of tidal tails from massive satellites
• Locating the orbits delineated by tidal streams
• Fitting orbits to tidal streams with proper motions
• An application of Galactic parallax: the distance to the tidal stream GD-1

Cited by in corpus (82)

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• The Local Dark Matter Density
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• The shape of the inner Milky Way halo from observations of the Pal 5 and GD-1 stellar streams
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• Inferring the Andromeda Galaxy's mass from its giant southern stream with Bayesian simulation sampling
• A sharper view of Pal 5's tails: Discovery of stream perturbations with a novel non-parametric technique
• Linear perturbation theory for tidal streams and the small-scale CDM power spectrum
• Constraining the Milky Way Halo Potential with the GD-1 stellar stream
• Novel constraints on the particle nature of dark matter from stellar streams
• STREAMFINDER I: A New Algorithm for detecting Stellar Streams
• Dynamical modeling of tidal streams
• A review of action estimation methods for galactic dynamics
• Generation of mock tidal streams
• Stream-orbit misalignment I: The dangers of orbit-fitting
• Galactic Archaeology. The dwarfs that survived and perished
• The Pal 5 Star Stream Gaps
• Milky Way Mass and Potential Recovery Using Tidal Streams in a Realistic Halo
• Dipping Our Toes in the Water: First Models of GD-1 as a Stream
• Discovery of a cold stellar stream in the ATLAS DR1 data
• Stream-orbit misalignment II: A new algorithm to constrain the Galactic potential
• Evidence of a population of dark subhalos from Gaia and Pan-STARRS observations of the GD-1 stream
• Gaps in the GD-1 Star Stream
• Kinematics and simulations of the stellar stream in the halo of the Umbrella Galaxy
• The effect of the LMC on the Milky Way system
• Dynamics of stream-subhalo interactions
• Constraining the distribution of dark matter in dwarf spheroidal galaxies with stellar tidal streams
• Probing the nature of dark matter particles with stellar streams
• Stray, swing and scatter: angular momentum evolution of orbits and streams in aspherical potentials
• Shepherding Tidal Debris with the Galactic Bar: The Ophiuchus Stream
• Using gaps in N-body tidal streams to probe missing satellites
• Inferring the gravitational potential of the Milky Way with a few precisely measured stars
• The Dynamics of Star Stream Gaps
• Angle-action estimation in a general axisymmetric potential
• Searching for the GD-1 Stream Progenitor in Gaia DR2 with Direct N-body Simulations
• Probabilistic model for constraining the Galactic potential using tidal streams
• Constraining the Milky Way Halo Shape Using Thin Streams
• Energy wrinkles and phase-space folds of the last major merger
• The Tidal Tails of 47 Tucanae
• Don't cross the streams: caustics from Fuzzy Dark Matter
• Detection of a 50 degree-long Trailing Tidal Tail for the Globular Cluster M5
• A fast algorithm for estimating actions in triaxial potentials
• Another Look at the EBS: A Stellar Debris Stream and a Possible Progenitor
• Dynamics for Galactic Archaeology
• An extended Pal 5 stream in Gaia DR2
• The discovery of tidal tails around the globular cluster NGC 7492 with Pan-STARRS1
• A statistical method for measuring the Galactic potential and testing gravity with cold tidal streams
• Analysing surveys of our Galaxy I: basic astrometric data
• Orbital Torus Imaging: Using Element Abundances to Map Orbits and Mass in the Milky Way
• Two New Halo Debris Streams in the Sloan Digital Sky Survey
• The evolution of streams in a time-dependent potential
• At a Crossroads: Stellar Streams in the South Galactic Cap
• The oblateness of the Milky Way dark matter halo from the stellar streams of NGC 3201, M68, and Palomar 5
• The course of the Orphan Stream in the Northern Galactic Hemisphere traced with Gaia DR2
• Self-gravity, resonances and orbital diffusion in stellar discs
• SMHASH: Anatomy of the Orphan Stream using RR Lyrae stars
• The structure of accreted stellar streams
• A Spatial Characterization of the Sagittarius Dwarf Galaxy Tidal Tails
• Dynamical invariants and diffusion of merger substructures in time-dependent gravitational potentials
• Charting Galactic Accelerations with Stellar Streams and Machine Learning
• Star Streams and the Assembly History of the Galaxy
• The ACTIONFINDER: An unsupervised deep learning algorithm for calculating actions and the acceleration field from a set of orbit segments
• On the Stability of Tidal Streams
• Tails from the Orphanage
• Star Streams in Triaxial Isochrone Potentials with Sub-Halos
• Extracting science from surveys of our Galaxy
• Stellar streams and dark substructure: the diffusion regime
• Tidal ribbons
• Tidal Debris as a Dark Matter Probe
• What a Tangled Web We Weave: Hermus as the Northern Extension of the Phoenix Stream
• Origins and Interpretation of Tidal Debris
• A Ghost in Boötes: The Least Luminous Disrupted Dwarf Galaxy
• Dynamical Properties of Collisionless Star Streams
• The influence of dark matter halo on the stellar stream asymmetry via dynamical friction
• On the behaviour of streams in angle and frequency spaces in different potentials
• Segue 2 Recently Collided with the Cetus-Palca Stream: New Opportunities to Constrain Dark Matter in an Ultra-Faint Dwarf
• Constraining the population of dark matter halo shapes using hierarchical inference with extragalactic stellar streams
• No Stream Left Unscathed: The imprint of a host galaxy
• Bar Properties and Star-by-Star Bar Membership via Action Conservation
• Understanding the Galaxy