A Low-Mass Stellar-Debris Stream Associated with a Globular Cluster Pair in the Halo

Abstract

There are expected to be physical relationships between the globular clusters (GCs) and stellar substructures in the Milky Way, not all of which have yet been found. We search for such substructures from a combined halo sample of SDSS blue horizontal-branch and SDSS+LAMOST RR Lyrae stars, cross-matched with astrometric information from $Gaia$ DR2. This is a sample of old stars which are also excellent tracers of structures, ideal for searching for ancient relics in the outer stellar halo. By applying the neural-network-based method StarGO to the full 4D dynamical space of our sample, we rediscover the Sagittarius Stream, and find the debris of the $Gaia$-Enceladus-Sausage (GES) and the Sequoia events in the outer halo, as well as their linkages with several GCs. Most importantly, we find a new, low-mass, debris stream associated with a pair of GCs (NGC 5024 and NGC 5053), which we dub LMS-1. This stream has a very polar orbit, and occupies a region between 10 to 20 kpc from the Galactic center. NGC 5024 (M53), the more-massive of the associated GC pair, is very likely the nuclear star cluster of a now-disrupted dwarf galaxy progenitor, based on the results from N-body simulations.

arXiv comment10 pages, 4 figures, accepted for ApJL

References in corpus (46)

• Gaia Data Release 2. Summary of the contents and survey properties
• Gaia Data Release 2: The astrometric solution
• The merger that led to the formation of the Milky Way's inner stellar halo and thick disk
• SEGUE: A Spectroscopic Survey of 240,000 stars with g=14-20
• The mass distribution and gravitational potential of the Milky Way
• Co-formation of the Galactic disc and the stellar halo
• The Milky Way's Circular Velocity Curve to 60 kpc and an Estimate of the Dark Matter Halo Mass from Kinematics of ~2400 SDSS Blue Horizontal Branch Stars
• AGAMA: Action-based galaxy modelling architecture
• LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) The survey science plan
• The SEGUE Stellar Parameter Pipeline. I. Description and Initial Validation Tests
• Evidence for Two Early Accretion Events That Built the Milky Way Stellar Halo
• Origin of the system of globular clusters in the Milky Way
• In disguise or out of reach: first clues about in-situ and accreted stars in the stellar halo of the Milky Way from Gaia DR2
• 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 SEGUE Stellar Parameter Pipeline. II. Validation with Galactic Globular and Open Clusters
• Proper motions and dynamics of the Milky Way globular cluster system from Gaia DR2
• Assessing the Milky Way Satellites Associated with the Sagittarius Dwarf Spheroidal Galaxy
• Multiple retrograde substructures in the Galactic halo: A shattered view of Galactic history
• Mapping the substructure in the Galactic halo with the next generation of astrometric satellites
• N-body modeling of globular clusters: Masses, mass-to-light ratios and intermediate-mass black holes
• Ghostly Tributaries to the Milky Way: Charting the Halo's Stellar Streams with the Gaia DR2 catalogue
• The Hercules-Aquila Cloud
• Evidence for an accretion origin for the outer halo globular cluster system of M31
• Globular Cluster Systems in Nearby Dwarf Galaxies: III. Formation Efficiencies of Old Globular Clusters
• Dynamical Relics of the Ancient Galactic Halo
• Off the beaten path: Gaia reveals GD-1 stars outside of the main stream
• The Milky Way Halo in Action Space
• Origin of the excess of high-energy retrograde stars in the Galactic halo
• The SEGUE K giant survey II: A Catalog of Distance Determinations for the SEGUE K giants in the Galactic Halo
• Absolute HST Proper Motion (HSTPROMO) of Distant Milky Way Globular Clusters: Galactocentric Space Velocities and the Milky Way Mass
• Exploring the Properties of the M31 Halo Globular Cluster System
• Common origin for Hercules-Aquila and Virgo Clouds in Gaia DR2
• StarGO: A New Method to Identify the Galactic Origins of Halo Stars
• An all-sky proper motion map of the Sagittarius stream using Gaia DR2
• A panoramic landscape of the Sagittarius stream in Gaia DR2 revealed with the STREAMFINDER spyglass
• Full 5D characterisation of the Sagittarius stream with Gaia DR2 RR Lyrae
• The outer halo globular cluster system of M31 - III. Relationship to the stellar halo
• A wide-field photometric survey for extratidal tails around five metal-poor globular clusters in the Galactic halo
• Strong RR Lyrae excess in the Hercules-Aquila Cloud
• Probing the galactic halo with RR Lyrae stars I: The catalog
• The Milky Way's stellar streams and globular clusters do not align in a Vast Polar Structure
• Revealing the Complicated Story of the Cetus Stream with StarGO
• Phase-space correlation in stellar streams of the Milky Way halo: The clash of Kshir and GD-1
• Chemical Abundances in NGC 5053: A Very Metal-Poor and Dynamically Complex Globular Cluster
• A Search for Extra-Tidal RR Lyrae in the Globular Cluster NGC 5024 and NGC 5053

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• Unveiling Galactic substructures with M Giant stars: A kinematic and chemical study based on LAMOST DR9, Gaia DR3 and APOGEE DR17
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