One Ring to Encompass them All: A giant stellar structure that surrounds the Galaxy

Abstract

We present evidence that the curious stellar population found by the Sloan Digital Sky Survey in the Galactic anticentre direction extends to other distant fields that skirt the plane of the Milky Way. New data, taken with the INT Wide Field Camera show a similar population, narrowly aligned along the line of sight, but with a Galactocentric distance that changes from ~15 kpc to \~20 kpc (over ~100 degrees on the sky). Despite being narrowly concentrated along the line of sight, the structure is fairly extended vertically out of the plane of the Disk, with a vertical scale height of 0.75+/-0.04 kpc. This finding suggests that the outer rim of the Galaxy ends in a low-surface brightness stellar ring. Presently available data do not allow us to ascertain the origin of the structure. One possibility is that it is the wraith of a satellite galaxy devoured long-ago by the Milky Way, though our favoured interpretation is that it is a perturbation of the disk, possibly the result of ancient warps. Assuming that the Ring is smooth and axisymmetric, the total stellar mass in the structure may amount to 2x10^8 up to 10^9 Solar masses.

8 pages, 10 (compressed) figures, accepted by MNRAS

References in corpus (17)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Dwarf Galaxies of the Local Group
• GAIA: Composition, Formation and Evolution of the Galaxy
• Radial Mixing in Galactic Discs
• The Ghost of Sagittarius and Lumps in the Halo of the Milky Way
• A giant stream of metal-rich stars in the halo of the galaxy M31
• The Effects of a Photoionizing UV Background on the Formation of Disk Galaxies
• Evidence for Stellar Substructure in the Halo and Outer Disk of M31
• Sinking Satellites and the Heating of Galaxy Discs
• The Kinematics, Orbit, and Survival of the Sagittarius Dwarf Spheroidal Galaxy
• The Milky Way's satellite population in a LambdaCDM universe
• Dynamical friction and the evolution of satellites in virialized halos: the theory of linear response
• Substructure in Dark Halos: Orbital Eccentricities and Dynamical Friction
• Two measures of the shape of the Milky Way's dark halo
• Galactic Indigestion: Numerical Simulations of the Milky Way's Closest Neighbor
• Constraints on Galaxy Formation from Stars in the Far Outer Disk of M31
• Contribution of the Large Magellanic Cloud to the Galactic Warp

Cited by in corpus (200)

• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• The Milky Way Tomography with SDSS: I. Stellar Number Density Distribution
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: I. Morphology of the Sagittarius Core and Tidal Arms
• Tracing Galaxy Formation with Stellar Halos I: Methods
• Galactic stellar haloes in the CDM model
• The Sagittarius Dwarf Galaxy: a Model for Evolution in a Triaxial Milky Way Halo
• A New Milky Way Dwarf Galaxy in Ursa Major
• The Local Dark Matter Density
• The accretion origin of the Milky Way's stellar halo
• Tracing Galaxy Formation with Stellar Halos II: Relating Substructure in Phase- and Abundance-Space to Accretion Histories
• A dwarf galaxy remnant in Canis Major: the fossil of an in-plane accretion onto the Milky Way
• The VMC Survey - I. Strategy and First Data
• Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
• Cold Dark Matter Substructure and Galactic Disks I: Morphological Signatures of Hierarchical Satellite Accretion
• Outer structure of the Galactic warp and flare: explaining the Canis Major over-density
• An Orphan in the "Field of Streams"
• Thin, thick and dark discs in LCDM
• The Sagittarius impact as an architect of spirality and outer rings in the Milky Way
• The stellar halo of the Galaxy
• On the accretion origin of a vast extended stellar disk around the Andromeda galaxy
• Rings and Radial Waves in the Disk of the Milky Way
• The Influence of Sagittarius and the Large Magellanic Cloud on the Milky Way Galaxy
• Mapping the stellar structure of the Milky Way thick disk and halo using SEGUE photometry
• Elemental Abundance Ratios in Stars of the Outer Galactic Disk. I. Open Clusters
• A comprehensive model for the Monoceros tidal stream
• Structure Finding in Cosmological Simulations: The State of Affairs
• Exploring Halo Substructure with Giant Stars XI: The Tidal Tails of the Carina Dwarf Spheroidal and the Discovery of Magellanic Cloud Stars in the Carina Foreground
• Dark matter in the Milky Way, II. the HI gas distribution as a tracer of the gravitational potential
• The QUEST RR Lyrae Survey II: The Halo Overdensities in the First Catalog
• A Two Micron All-Sky Survey View of the Sagittarius Dwarf Galaxy: II. Swope Telescope Spectroscopy of M Giant Stars in the Dynamically Cold Sagittarius Tidal Stream
• Spectroscopy of QUEST RR Lyrae Variables: the new Virgo Stellar Stream
• Exploring Halo Substructure with Giant Stars: Spectroscopy of Stars in the Galactic Anticenter Stellar Structure
• Luminosity functions for galaxies and quasars in the Spitzer Wide-Area Infrared Extra-galactic (SWIRE) Legacy survey
• Accretion relicts in the solar neighbourhood: debris from omegaCen's parent galaxy
• Substructure in Tidal Streams; Tributaries in the Anticenter Ring
• Response of the Milky Way's disc to the Large Magellanic Cloud in a first infall scenario
• Old open clusters in the outer Galactic disk
• Galactic Stellar Populations in the Era of SDSS and Other Large Surveys
• Antitruncated Stellar Disks via Minor Mergers
• The Overdensity in Virgo, Sagittarius Debris, and the Asymmetric Spheroid
• Halos around edge-on disk galaxies in the SDSS
• Reconstructing Galaxy Histories from Globular Clusters
• Mapping the Galactic Halo VIII: Quantifying substructure
• Elemental Abundance Ratios in Stars of the Outer Galactic Disk. III. Cepheids
• Stellar Streams and Clouds in the Galactic Halo
• Detection of the Main Sequence Turn-off of a Newly Discovered Milky Way Halo Structure in the Triangulum-Andromeda Region
• Galactic Archaeology. The dwarfs that survived and perished
• Tombaugh 2: The First Open Cluster with a Significant Abundance Spread or Embedded in a Cold Stellar Stream?
• A re-interpretation of the Triangulum-Andromeda stellar clouds: a population of halo stars kicked out of the Galactic disk
• The Canada-France Imaging Survey: First results from the u-band component
• Detection of the Keplerian decline in the Milky Way rotation curve
• The Observed and Predicted Spatial Distribution of Milky Way Satellite Galaxies
• On the identification of merger debris in the {\it Gaia} Era
• Gaia Early Data Release 3: The Galactic anticentre
• EGRET Excess of Diffuse Galactic Gamma Rays as Tracer of Dark Matter
• The PAndAS Field of Streams: stellar structures in the Milky Way halo toward Andromeda and Triangulum
• An updated survey of globular clusters in M31. II Newly discovered bright and remote clusters
• Discovery of an anomalous Sub Giant Branch in the Color Magnitude Diagram of omega Centauri
• On the nature of the ring-like structure in the outer Galactic disk
• A panoramic view of the Milky Way analogue NGC 891
• The Caustic Ring Model of the Milky Way Halo
• De-contamination of cosmological 21-cm maps
• Revealing Substructure in the Galactic Halo - The SEKBO RR Lyrae Survey
• Star Clusters in the Galactic Anticenter Stellar Structure and the Origin of Outer Old Open Clusters
• On the identification of substructure in phase-space using orbital frequencies
• Identifying stellar streams in the 1st RAVE public data release
• Signatures of minor mergers in the Milky Way disc I: The SEGUE stellar sample
• Signatures of minor mergers in Milky Way-like disc kinematics: Ringing revisited
• Cepheid Variables in the Flared Outer Disk of our Galaxy
• Galactic halo stellar structures in the Triangulum-Andromeda region
• The Complex Structure of Stars in the Outer Galactic Disk as revealed by Pan-STARRS1
• Detection of the Canis Major galaxy at (l;b)=(244;-8) and in the background of Galactic open clusters
• Spectroscopic Survey of the Galaxy with Gaia II. The expected science yield from the Radial Velocity Spectrometer
• The Abundance Gradient in the Extremely Faint Outer Disk of NGC 300
• A Distant Extended Spiral Arm in the Fourth Quadrant of the Milky Way
• Common origin for Hercules-Aquila and Virgo Clouds in Gaia DR2
• The core of the Canis Major galaxy as traced by Red Clump stars
• Stellar Population Variations in the Milky Way's Stellar Halo
• Evidence of a dwarf galaxy stream populating the inner Milky Way Halo
• The Virgo stellar over-density: Mapping the infall of the Sagittarius tidal stream onto the Milky Way disk
• Kinematics and Chemistry of Stars Along the Sagittarius Trailing Tidal Tail and Constraints on the Milky Way Mass Distribution
• An HST/ACS investigation of the spatial and chemical structure and sub-structure of NGC 891, a Milky Way analogue
• On the Origin of Dynamically Cold Rings Around the Milky Way
• Exploring Halo Substructure with Giant Stars. VI. Extended Distributions of Giant Stars Around the Carina Dwarf Spheroidal Galaxy -- How Reliable Are They?
• The Century Survey Galactic Halo Project III: A Complete 4300 deg^2 Survey of Blue Horizontal Branch Stars in the Metal-Weak Thick Disk and Inner Halo
• On the recent star formation history of the Milky Way disk
• Spectroscopy of Bright QUEST RR Lyrae Stars: Velocity Substructures toward Virgo
• The Structure of the Sagittarius Stellar Stream as Traced by Blue Horizontal Branch Stars
• Why the Canis Major overdensity is not due to the Warp: analysis of its radial profile and velocities
• Streams in the Aquarius stellar haloes
• uvby-βphotometry of high-velocity and metal-poor stars XI. Ages of halo and old disk stars
• Evidence for the Third Stellar Population in the Milky Way's Disk
• TriAnd and its Siblings: Satellites of Satellites in the Milky Way Halo
• The AAT/WFI survey of the Monoceros Ring and Canis Major Dwarf galaxy: I. from l = (193 - 276)o
• Exploring Halo Substructure with Giant Stars: The Nature of the Triangulum-Andromeda Stellar Features
• Testing galaxy formation models with the GHOSTS survey: The color profile of M81's stellar halo
• Exploring the Virgo Stellar Stream with SEKBO Survey RR Lyrae Stars
• The Pristine survey -- XXIII. Data Release 1 and an all-sky metallicity catalogue based on Gaia DR3 BP/RP spectro-photometry
• A radial velocity survey of low Galactic latitude structures: I. Kinematics of the Canis Major dwarf galaxy
• On Rings and Streams in the Galactic Anti-Center
• Constraining the Milky Way Halo Shape Using Thin Streams
• Mapping the Monoceros Ring in 3D with Pan-STARRS1
• Metallicities and Radial Velocities of Five Open Clusters Including a New Candidate Member of the Monoceros Stream
• A panoramic VISTA of the stellar halo of NGC 253
• The fall of the Northern Unicorn: Tangential motions in the Galactic Anti-centre with SDSS and Gaia
• The Tidal Streams of Disrupting Subhaloes in Cosmological Dark Matter Haloes
• The INT/WFC survey of the Monoceros Ring: Accretion origin or Galactic Anomaly?
• The Importance of Interactions for Mass Loss from Satellite Galaxies in Cold Dark Matter Haloes
• Exploring the pertubed Milky Way disk and the substructures of the outer disk
• Elemental Abundance Ratios in Stars of the Outer Galactic Disk. II. Field Red Giants
• The Chemical Evolution of the Monoceros Ring/Galactic Anticenter Stellar Structure
• Kinematic Discovery of a Stellar Stream located in Pisces
• Orbital evidences for dark-matter-free Milky Way dwarf spheroidal galaxies
• The Disk and Extraplanar Environment of NGC 247
• BVI photometry of the very old open cluster Berkeley 17
• The hunt for the Milky Way's accreted disc
• Absolute Proper Motion of the Canis Major Dwarf Galaxy Candidate
• The high-velocity clouds and the Magellanic Clouds
• Carbon Stars and other Luminous Stellar Populations in M33
• A self-consistent dynamical model of the Milky Way disc adjusted to Gaia data
• Constraining the Galactic structure parameters with the XSTPS-GAC and SDSS photometric surveys
• The stellar population content of the thick disk and halo of the Milky Way analogue NGC 891
• Photometry and Spectroscopy of Old, Outer Disk Star Clusters: vdB-Hagen 176, Berkeley 29 and Saurer 1
• The population in the background of open clusters: Tracer of the Norma-Cygnus arm
• The Dog on the Ship: The "Canis Major Dwarf Galaxy" as an Outlying Part of the Argo Star System
• Abundances and kinematics for ten anticentre open clusters
• Stellar disc streams as probes of the Galactic potential and satellite impacts
• Halo Velocity Groups in the Pisces Overdensity
• Surveying the Inner Halo of the Galaxy with 2MASS-Selected Horizontal Branch Candidates
• A deep view of the Monoceros ring in the Anticenter direction: clues of its extra-Galactic origin
• Identifying Galactic Halo Substructure in 6D Phase-space Using $\sim$13,000 LAMOST K Giants
• VVVX-Gaia Discovery of a Low Luminosity Globular Cluster in the Milky Way Disk
• Does the Second Caustic Ring of Dark Matter Cause the Monoceros Ring of Stars ?
• Evidence for Dark Matter Annihilation from Galactic Gamma Rays?
• Slicing The Monoceros Overdensity with Suprime-Cam
• On the relevance of chaos for halo stars in the Solar Neighbourhood
• On the absence of dark matter in dwarf galaxies surrounding the Milky Way
• Very Luminous Carbon Stars in the Outer Disk of the Triangulum Spiral Galaxy
• Quantifying the Smoothness of the Stellar Halo: A Link to Accretion History
• A Canis Major over-density imaging survey. I. Stellar content and star-count maps : A distinctly elongated body of main sequence stars
• The stellar content of the Hamburg/ESO survey. III. Field horizontal-branch stars in the Galaxy
• A Deep Proper-Motion Survey in Kapteyn Selected Areas: I. Survey Description and First Results for Stars in the Tidal Tail of Sagittarius and in the Monoceros Ring
• Update on the Cetus Polar Stream and its Progenitor
• Excess of EGRET Galactic Gamma Ray Data interpreted as Dark Matter Annihilation
• Cresting the wave: Proper motions of the Eastern Banded Structure
• A radial velocity survey of low Galactic latitude structures: III. The Monoceros Ring in front of the Carina and Andromeda galaxies
• New Signatures of the Milky Way Formation in the Local Halo and Inner Halo Streamers in the Era of Gaia
• First Chemical Analysis of Stars in The Triangulum-Andromeda Star Cloud
• Unearthing Foundations of a Cosmic Cathedral: Searching the Stars for M33's Halo
• Exploring the Dust Content of Galactic Halos with Herschel III. NGC 891
• The outer disc in shambles: blind detection of Monoceros and ACS with Gaia's astrometric sample
• The Dark Matter Density in the Solar Neighborhood reconsidered
• The thickness of HI in galactic discs under MOND: theory and application to the Galaxy
• UVES observations of the Canis Major overdensity
• The old anticentre open cluster Berkeley 32: membership and fundamental parameters
• Signatures of star streams in the phase space distribution of nearby halo stars
• Fluorine Abundances in the Galactic Disk
• The Millennium Galaxy Catalogue: Star counts and the Structure of the Galactic Stellar Halo
• The hot stars in orbit around the M31 central supermassive black hole: are they young or old?
• On the relevance of chaos for halo stars in the solar neighbourhood II
• Radial Velocity and Metallicity of the Globular Cluster IC4499 Obtained with AAOmega
• Kinematics of Stars in Kapteyn Selected Area 71: Sampling the Monoceros and Sagittarius Tidal Streams
• Gravitational potential of a homogeneous circular torus: new approach
• Fluorine Abundances in the Galactic Nuclear Star Cluster
• A Map of the Local Velocity Substructure in the Milky Way Disk
• Kinematics in Kapteyn's Selected Area 76: Orbital Motions Within the Highly Substructured Anticenter Stream
• Red Supergiants in the Disk of M81: Tracing the Spatial Distribution of Star Formation 25 Million Years in the Past
• The Implications of Local Fluctuations in the Galactic Midplane for Dynamical Analysis in the Gaia Era
• Exploring the Galactic Anticenter substructure with LAMOST & Gaia DR2
• Deep Astrometric Standards (DAS) and Galactic Structure
• A Sagittarius-Induced Origin for the Monoceros Ring
• On the Origin of the Monoceros Ring - I: Kinematics, proper motions, and the nature of the progenitor
• Old open clusters and the Galactic metallicity gradient: Berkeley 20, Berkeley 66, and Tombaugh 2
• A radial velocity survey of low Galactic latitude structures: II. The Monoceros Ring behind the Canis Major dwarf galaxy
• Stellar substructures in the solar neighbourhood. I. Kinematic group 3 in the Geneva-Copenhagen survey
• Mapping the Asymmetric Thick Disk: II Distance, Size and Mass of the Hercules Thick Disk Cloud
• The Void in the Sculptor Group Spiral Galaxy NGC 247
• GCN: a gaseous Galactic halo stream?
• Stellar substructures in the solar neighbourhood IV. Kinematic Group 1 in the Geneva-Copenhagen survey
• Effects of a caustic ring of dark matter on the distribution of stars and interstellar gas
• The global structure of the Milky Way's stellar halo based on the orbits of local metal-poor stars
• Disc-Halo Interactions in ΛCDM
• Detection of a Stellar Stream Behind Open Cluster NGC 188: Another Part of the Monoceros Stream
• Mapping the Asymmetric Thick Disk I. A Search for Triaxiality
• STRRINGS: STReams in Residual Images of Nearby GalaxieS
• Discovery of the Polar Ring Galaxies with deep learning
• Introduction to Tidal Streams
• The dark connection between the Canis Major dwarf, the Monoceros ring, the gas flaring, the rotation curve and the EGRET excess of diffuse Galactic Gamma Rays
• Indirect Evidence for WIMP Annihilation from Diffuse Galactic Gamma Rays
• Tomography of stellar halos: what does anisotropy in a stellar halo tell us?
• Constraints on Galaxy Structure and Evolution from the Light of Nearby Systems
• The Canis Major Dwarf Galaxy
• Searching for the lost Unicorn: a prominent feature in the radial velocity distribution of stars in Vela from Gaia DR2 data
• The dark connection between the EGRET excess of diffuse Galactic gamma rays, the Canis Major dwarf, the Monoceros ring, the INTEGRAL 511 keV annihilation line, the gas flaring and the Galactic rotation curve
• Probing the spatial and velocity anisotropies in stellar halos from the Aquarius simulations
• Using two point correlation functions to understand the assembly histories of Milky Way-like galaxies
• The mass and redshift dependence of halo star clustering
• Finding RR Lyrae Stars with SkyMapper: an Observational Test
• Mapping low-latitude stellar substructure with SEGUE photometry
• Modell zur Entstehung eines Rings aus Dunkler Materie in der Milchstraßenebene