Transient spiral structure and the disc velocity substructure in Gaia DR2

Abstract

The second data release from ESA's Gaia mission has revealed many ridge-like structures in the velocity distribution of the Milky Way. We show that these can arise naturally from winding transient spiral structure that is commonly seen in N-body simulations of disk galaxies. We construct test particle models of the winding spiral structure, and compare the resulting distribution of orbits with the observed two-dimensional velocity distribution in the extended solar neighbourhood and with the distribution of rotational velocities over 8 kpc along the Sun--Galactic-centre--Galactic anti-centre line. We show that the ridges in these observations are well reproduced by the winding spiral model. Additionally, we demonstrate that the transient winding spiral potential can create a Hercules-like feature in the kinematics of the solar neighbourhood, either alone, or in combination with a long-slow bar potential.

11 pages, 7 figures, accepted for publication in MNRAS

References in corpus (26)

• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• The Gaia mission
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• galpy: A Python Library for Galactic Dynamics
• The Milky Way's circular velocity curve between 4 and 14 kpc from APOGEE data
• The Structure of the Milky Way's Bar Outside the Bulge
• Dawes Review 4: Spiral Structures in Disc Galaxies
• The Tycho-Gaia astrometric solution. How to get 2.5 million parallaxes with less than one year of Gaia data
• Is the Milky Way ringing? The hunt for high velocity streams
• Transient spirals as superposed instabilities
• Radial Distribution of Stellar Motions in Gaia DR2
• The Blueshifting and Baldwin effects for the [OIII] 5007 Emission Line in Type 1 Active Galactic Nuclei
• Stellar Kinematic Constraints on Galactic Structure Models Revisited: Bar and Spiral Arm Resonances
• The power spectrum of the Milky Way: Velocity fluctuations in the Galactic disk
• Tracing the Hercules stream with Gaia and LAMOST: new evidence for a fast bar in the Milky Way
• The 4:1 Outer Lindblad Resonance of a long slow bar as a potential explanation for the Hercules stream
• Phase Space Structure in the Solar Neighbourhood
• Gas and Stellar Motions and Observational Signatures of Co-Rotating Spiral Arms
• Spiral arm crossings inferred from ridges in Gaia stellar velocity distributions
• Gaia DR1 evidence of disrupting Perseus Arm
• The Hercules stream as seen by APOGEE-2 South
• The stellar kinematics of co-rotating spiral arms in Gaia mock observations
• Tracing the Hercules stream around the Galaxy
• Modelling resonances and orbital chaos in disk galaxies. Application to a Milky Way spiral model
• Stars with fast Galactic rotation observed in Gaia TGAS: a signature driven by the Perseus arm?
• Detection of a dearth of stars with zero angular momentum in the solar neighbourhood

Cited by in corpus (76)

• The Milky Way total mass profile as inferred from Gaia DR2
• Gaia Early Data Release 3: The Gaia Catalogue of Nearby Stars
• Footprints of the Sagittarius dwarf galaxy in the $Gaia$ data set
• Dark matter local density determination: recent observations and future prospects
• The Galactic Disc in Action Space as seen by Gaia DR2
• Resonance sweeping by a decelerating Galactic bar
• The Gravitational Force Field of the Galaxy Measured From the Kinematics of RR Lyrae in Gaia
• The GALAH survey and Gaia DR2: Linking ridges, arches and vertical waves in the kinematics of the Milky Way
• On the Milky Way spiral arms from open clusters in Gaia EDR3
• Spirals in galaxies
• Signatures of resonance and phase mixing in the Galactic disc
• Tree-ring structure of Galactic bar resonance
• On the ridges, undulations & streams in Gaia DR2: Linking the topography of phase-space to the orbital structure of an N-body bar
• Identifying resonances of the Galactic bar in Gaia DR2: I. Clues from action space
• The GALAH Survey: Chemodynamics of the Solar Neighbourhood
• Hic sunt dracones: Cartography of the Milky Way spiral arms and bar resonances with Gaia Data Release 2
• Spiral instabilities: Mechanism for recurrence
• Kinematics with Gaia DR2: The Force of a Dwarf
• Discriminating among theories of spiral structure using Gaia DR2
• Galaxy Zoo: Unwinding the Winding Problem - Observations of Spiral Bulge Prominence and Arm Pitch Angles Suggest Local Spiral Galaxies are Winding
• Modeling the Milky Way as a Dry Galaxy
• Stellar halo substructure generated by bar resonances
• Chemo-kinematics of the Milky Way spiral arms and bar resonances: connection to ridges and moving groups in the Solar vicinity
• Trojans in the Solar Neighborhood
• Trimodal structure of Hercules stream explained by originating from bar resonances
• Strong chemical tagging with APOGEE: 21 candidate star clusters that have dissolved across the Milky Way disc
• Galactic Bar Resonances Inferred from Kinematically Hot Stars in Gaia EDR3
• Gaia-DR2 extended kinematical maps. Part II: Dynamics in the Galactic disk explaining radial and vertical velocities
• Secularly powered outflows from AGN: the dominance of non-merger driven supermassive black hole growth
• Tidally induced spiral arm wraps encoded in phase space
• Did Sgr cause the vertical waves in the solar neighbourhood?
• Exploring the origin of moving groups and diagonal ridges by simulations of stellar orbits and birthplaces
• From a Different Star: 3I/ATLAS in the context of the Ōtautahi-Oxford interstellar object population model
• Kiloparsec-scale AGN Outflows and Feedback in Merger-Free Galaxies
• How do different spiral arm models impact the ISM and GMC population?
• Orbital Torus Imaging: Using Element Abundances to Map Orbits and Mass in the Milky Way
• Using Commensurabilities and Orbit Structure to Understand Barred Galaxy Evolution
• The bar resonances and low angular momentum moving groups in the Galaxy revealed by stellar ages
• Weighing the Galactic disk using phase-space spirals I. Tests on one-dimensional simulations
• Moving groups across Galactocentric radius with Gaia DR3
• Diagonal Ridge pattern of different age populations found in Gaia DR2 with LAMOST Main-Sequence-Turn-Off and OB type Stars
• From ridges in the velocity distribution to wiggles in the rotation curve
• From ridges to manifolds: 3D characterization of the moving groups in the Milky Way disc
• The power of co-ordinate transformations in dynamical interpretations of Galactic structure
• Kinetic Tomography. II. A second method for mapping the velocity field of the Milky Way Interstellar Medium and a comparison with spiral structure models
• Metallicity dependence of the Hercules stream in Gaia/RAVE data -- explanation by non-closed orbits
• Chemodynamical signatures of bar resonances in the Galactic disk: current data and future prospects
• Kinematic footprint of the Milky Way spiral arms in Gaia EDR3
• The Milky Way Bar Pattern Speed using Hercules and Gaia DR3
• Distribution and kinematics of 26Al in the Galactic disc
• Disentangling the Arcturus stream
• Estimating the local dark matter density in a non-axisymmetric wobbling disc
• The most luminous, merger-free AGN show only marginal correlation with bar presence
• Remarkable migration of the solar system from the innermost Galactic disk; a wander, a wobble, and a climate catastrophe on the Earth
• Predicting Interstellar Object Chemodynamics with Gaia
• Stellar migration in the Auriga simulations
• Radial velocities in the outermost disk toward the anticenter
• Spatial and Kinematic Clustering of Stars in the Galactic Disk
• Radial Wave in the Galactic Disk: New Clues to Discriminate Different Perturbations
• Impact of bar resonances in the velocity-space distribution of the solar neighbourhood stars in a self-consistent $N$-body Galactic disc simulation
• Solar System Migration Points to a Renewed Concept: Galactic Habitable Orbits
• Constraints on the history of Galactic spiral arms revealed by Gaia GSP-Spec alpha-elements
• A non-axisymmetric potential for the Milky Way disk
• Radial and azimuthal gradients of the moving groups in Gaia DR3: The slow/fast bar degeneracy problem
• On the Migration Origin of the Hercules Moving Group with GAIA, LAMOST, APOGEE, and GALAH Surveys
• Dynamically Produced Moving Groups in Interacting Simulations
• Measuring the Matter Density of the Galactic Disk Using Stellar Streams
• Dynamical streams in the local stellar halo
• The emptiness inside: Finding gaps, valleys, and lacunae with geometric data analysis
• Kinematic-Chemical analysis and Time tagging for the Diagonal Ridge Structure of the Galactic Outer Disk with LAMOST Red Giant Branch Stars
• Weighing the Darkness II: Astrometric Measurement of Partial Orbits with Gaia
• On the origin of the Hercules group: I. chemical signatures indicating the outer bar origin
• Resonant Effects of a Bar on the Galactic Disk Kinematics Perpendicular to Its Plane
• Moving Groups in the Solar Neighborhood with Gaia, APOGEE, GALAH, and LAMOST: Dynamical Effects Gather Gas and the Ensuing Star Formation Plays an Important Role in Shaping the Stellar Velocity Distributions
• Features of the Residual Velocity Ellipsoid of Hot Subdwarfs from the Gaia DR2 Catalog
• Wrinkles in Time. II. Stellar Age Trends in Kinematic Signatures from Transient Spiral Structure