The Vast Polar Structure of the Milky Way Attains New Members

Abstract

The satellite galaxies of the Milky Way (MW) align with and preferentially orbit in a vast polar structure (VPOS), which also contains globular clusters, stellar and gaseous streams. Similar alignments have been discovered around several other host galaxies. We test whether recently discovered objects in the MW halo, the satellite galaxy/globular cluster transition object named PSO J174.0675-10.8774 or Crater and three stellar streams, are part of the VPOS. Crater is situated close to the VPOS. Incorporating the new object in the VPOS-plane fit slightly improves the alignment of the plane with other features such as the Magellanic stream and the average orbital plane of the satellites co-orbiting in the VPOS. We predict Crater's proper motion by assuming that it, too, orbits in the VPOS. One of the three streams aligns well with the VPOS. Surprisingly, it appears to lie in the exact same orbital plane as the Palomar 5 stream and shares its distance, suggesting a direct connection between the two. The stream also crosses close to the Fornax dwarf galaxy and is oriented approximately along the galaxy's direction of motion. The two other streams cannot align closely with the VPOS because they were discovered in the direction of M31/M33, which is outside of the satellite structure. The VPOS thus attains two new members. This further emphasizes that the highly anisotropic and correlated distribution of satellite objects requires an explanation beyond the suggestion that the MW satellite system is an extreme statistical outlier of a $\Lambda$CDM sub-halo system.

arXiv comment8 pages, 3 figures, 3 tables. Published in ApJ

References in corpus (50)

• The observed properties of dwarf galaxies in and around the Local Group
• The Field of Streams: Sagittarius and its Siblings
• Mass models of the Milky Way
• The Sagittarius Dwarf Galaxy: a Model for Evolution in a Triaxial Milky Way Halo
• A Vast Thin Plane of Co-rotating Dwarf Galaxies Orbiting the Andromeda Galaxy
• Constraining the Milky Way potential with a 6-D phase-space map of the GD-1 stellar stream
• Stellar Tidal Streams in Spiral Galaxies of the Local Volume: A Pilot Survey with Modest Aperture Telescopes
• The great disk of Milky-Way satellites and cosmological sub-structures
• The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way
• 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
• The properties of Galactic globular cluster sub-systems
• Four New Stellar Debris Streams in the Galactic Halo
• The Origin of the Bifurcation in the Sagittarius Stream
• The dark matter crisis: falsification of the current standard model of cosmology
• Local-Group tests of dark-matter Concordance Cosmology: Towards a new paradigm for structure formation
• Confirmation of Faint Dwarf Galaxies in the M81 Group
• Dwarf Galaxy Planes: the discovery of symmetric structures in the Local Group
• The rotationally stabilized VPOS and predicted proper motions of the Milky Way satellite galaxies
• Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies
• The Three-Dimensional Structure of the M31 Satellite System; Strong Evidence for an Inhomogeneous Distribution of Satellites
• High-resolution simulations of galaxy mergers: Resolving globular cluster formation
• A 22 Degree Tidal Tail for Palomar 5
• Was the Progenitor of the Sagittarius Stream a Disc Galaxy?
• The Orbit of the Orphan Stream
• The vast thin plane of M31 co-rotating dwarfs: an additional fossil signature of the M31 merger and of its considerable impact in the whole Local Group
• Identification of old tidal dwarfs near early-type galaxies from deep imaging and HI observations
• A thousand shadows of Andromeda: rotating planes of satellites in the Millennium-II cosmological simulation
• The Atlas-3D project - IX. The merger origin of a fast and a slow rotating Early-Type Galaxy revealed with deep optical imaging: first results
• A new distant Milky Way globular cluster in the Pan-STARRS1 3π survey
• ATLAS lifts the Cup: Discovery of a New Milky Way satellite in Crater
• Did the Milky Way dwarf satellites enter the halo as a group?
• On the Distribution of Orbital Poles of Milky Way Satellites
• The PAndAS Field of Streams: stellar structures in the Milky Way halo toward Andromeda and Triangulum
• A Cold Milky Way Stellar Stream in the Direction of Triangulum
• Dwarf-spheroidal satellites: are they of tidal origin?
• Discovery of a cold stellar stream in the ATLAS DR1 data
• The failures of the standard model of cosmology require a new paradigm
• Making Counter-Orbiting Tidal Debris: The Origin of the Milky Way Disc of Satellites
• Stream-orbit misalignment II: A new algorithm to constrain the Galactic potential
• Gaps in the GD-1 Star Stream
• Star Formation History and Chemical Evolution of the Sextans Dwarf Spheroidal Galaxy
• Can filamentary accretion explain the orbital poles of the Milky Way satellites?
• Perseus I and the NGC 3109 association in the context of the Local Group dwarf galaxy structures
• The Next Generation Virgo Cluster Survey. IV. NGC 4216: A Bombarded Spiral in the Virgo Cluster
• The globular cluster system of the Milky Way: accretion in a cosmological context
• Dwarf spheroidal satellites of the Milky Way from dark matter free tidal dwarf galaxy progenitors: maps of orbits
• Kinematic Discovery of a Stellar Stream located in Pisces
• Finding halo streams with a pencil-beam survey: new wraps in the Sagittarius stream
• VLT Observations of NGC 1097's "dog-leg" tidal stream

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• Challenges for $\Lambda$CDM: An update
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• The Planes of Satellite Galaxies Problem, Suggested Solutions, and Open Questions
• The Milky Way's Disk of Classical Satellite Galaxies in Light of Gaia DR2
• DGSAT: Dwarf Galaxy Survey with Amateur Telescopes I. Discovery of low surface brightness systems around nearby spiral galaxies
• Gaia EDR3 proper motions of Milky Way dwarfs I: 3D Motions and Orbits
• The new Milky Way satellites: alignment with the VPOS and predictions for proper motions and velocity dispersions
• On the persistence of two small-scale problems in ΛCDM
• Broken into Pieces: ATLAS and Aliqa Uma as One Single Stream
• An Updated SMC and Magellanic Bridge Catalog of Star Clusters, Associations and Related Objects
• Origin of the Local Group satellite planes
• Simulated ΛCDM analogues of the thin Plane of Satellites around the Andromeda galaxy are not kinematically coherent structures
• The resonant nature of tidal stirring of disky dwarf galaxies orbiting the Milky Way
• Dissipative Dark Matter and the Andromeda Plane of Satellites
• The Clustering of Orbital Poles Induced by the LMC: Hints for the Origin of Planes of Satellites
• The Milky Way's stellar streams and globular clusters do not align in a Vast Polar Structure
• The alignment of SDSS satellites with the VPOS: effects of the survey footprint shape
• Modeling GD-1 Gaps in a Milky-Way Potential
• The mass-metallicity relation of tidal dwarf galaxies
• Possible smoking-gun evidence for initial mass segregation in re-virialized post-gas expulsion globular clusters
• Do halos that form early, have high concentration, are part of a pair, or contain a central galaxy potential host more pronounced planes of satellite galaxies?
• An updated detailed characterization of planes of satellites in the MW and M31
• An extended stellar halo discovered in the Fornax dwarf spheroidal using Gaia EDR3
• The shape alignment of satellite galaxies in galaxy pairs in SDSS
• Axial Anomaly in Galaxies and the Dark Universe
• Classifying the satellite plane membership of Centaurus A's dwarf galaxies using orbital alignment constraints
• Impact of distance determinations on Galactic structure. II. Old tracers
• Testing Lorentz invariance of dark matter with satellite galaxies
• The Orthogonally Aligned Dark Halo of an Edge-on Lensing Galaxy in the Hubble Frontier Fields: A Challenge for Modified Gravity
• Proper Motions of the Satellites of M31
• Lessons from the Local Group (and beyond) on dark matter
• Dark sector domain walls could explain the observed planes of satellites
• Discovery of rotation axis alignments in Milky Way globular clusters
• Investigating the origin of the Milky Way streams. A revised look at their orbital pole distribution in light of precession effects