Phase-space correlation in stellar streams of the Milky Way halo: The clash of Kshir and GD-1

Abstract

We report the discovery of a 70-degree long stellar stream in the Milky Way halo, which criss-crosses the well known "GD-1" stream. We show that this new stellar structure ("Kshir") and GD-1 lie at similar distance, and are remarkably correlated in kinematics. We propose several explanations for the nature of this new structure and its possible association with GD-1. However, a scenario in which these two streams were accreted onto the Milky Way within the same dark matter sub-halo seems to provide a natural explanation for their phase-space entanglement, and other complexities of this coupled-system.

6 pages, 3 figures, 1 Table, accepted for publication in ApJ

References in corpus (7)

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• The Cosmic Hunt for Members in the Outskirts of Ultra Faint Dwarf Galaxies: Ursa Major I, Coma Berenices, and Boötes I
• Exploring the outskirts of globular clusters: the peculiar kinematics of NGC 3201
• The impact of a massive Sagittarius dSph on GD-1-like streams
• A chemo-dynamical link between the Gjöll stream and NGC 3201
• The e-TidalGCs Project: Modeling the extra-tidal features generated by Galactic globular clusters
• DELVE-ing into the Jet: a thin stellar stream on a retrograde orbit at 30 kpc
• GD-1 Stellar Stream and Cocoon in the DESI Early Data Release
• The Milky Way, Coming into Focus: Precision Astrometry Probes its Evolution, and its Dark Matter
• New constraints on the dark matter density profiles of dwarf galaxies from proper motions of globular cluster streams
• Stellar streams and dark substructure: the diffusion regime
• A Ghost in Boötes: The Least Luminous Disrupted Dwarf Galaxy
• Inferring the density and membership of stellar streams with flexible models: The GD-1 stream in Gaia Data Release 3
• One Stream or Two -- Exploring Andromeda's North West Stream
• Identifying substructure associations in the Milky Way halo using chemo-kinematic tagging
• Identification of a dwarf galaxy stream in Gaia, and its possible association with the VPOS structure
• Tracing Milky Way substructure with an RR Lyrae hierarchical clustering forest
• A new member of the Milky Way's family tree: Characterizing the Pontus merger of our Galaxy