Kinematics of Tidal Debris from Omega Centauri's Progenitor Galaxy

Abstract

We present the kinematic properties of a tidally disrupted dwarf galaxy in the Milky Way, based on the hypothesis that its central part once contained the most massive Galactic globular cluster, omega Cen. Dynamical evolution of a self-gravitating progenitor galaxy that follows the present-day and likely past orbits of omega Cen is calculated numerically and the kinematic nature of their tidal debris is analyzed, combined with randomly generated stars comprising spheroidal halo and flat disk components. We show that the retrograde rotation of the debris stars at $\sim -100$ km/s accords with a recently discovered, large radial velocity stream at $\sim 300$ km/s towards the Galactic longitude of $\sim 270^{\circ }$. These stars also contribute, only in part, to a reported retrograde motion of the outer halo at the North Galactic Pole. The prospects for future debris searches and the implications for the early evolution of the Galaxy are briefly presented.

arXiv comment14 pages, 3 figures, accepted for publication in ApJ Letters

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Cited by in corpus (36)

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• A spectroscopic survey of thick disc stars outside the solar neighbourhood
• Tracing the formation of the Milky Way through ultra metal-poor stars
• Kinematic Decoupling of Globular Clusters with Extended Horizontal-Branch
• Globular Clusters with Dark Matter Halos. II. Evolution in Tidal Field
• Exploring Halo Substructure with Giant Stars: Substructure in the Local Halo as Seen in the Grid Giant Star Survey Including Extended Tidal Debris from Omega Centauri
• Formation of Multiple Populations in Globular Clusters: Another Possible Scenario
• CCD Photometry of the Globular Cluster omega Centauri. II. Stellar Populations and Age-Metallicity Relation
• The non-peculiar velocity dispersion profile of the stellar system omega Centauri
• The Age and Metallicity Relation of Omega Centauri
• Evidence of tidal debris from Omega Cen in the Kapteyn Group
• The Complexity of the Cetus Stream Unveiled from the Fusion of STREAMFINDER and StarGO
• Dynamical friction for dark halo satellites: effects of tidal massloss and growing host potential
• The Disk and Extraplanar Environment of NGC 247
• A Spectroscopic Survey for Omega Centauri Members at and beyond the Cluster Tidal Radius
• Searching for tidal tails around $\omega$ Centauri using RR Lyrae Stars
• Formation of giant globular cluster G1 and the origin of the M31 stellar halo
• Through thick and thin: Structure of the Galactic thick disc from extragalactic surveys
• RAVE stars tidally stripped/ejected from $\omega$ Centauri globular cluster
• A Survey of Proper Motion Stars. XVII. A Deficiency of Binary Stars on Retrograde Galactic Orbits and the Possibility that omega Centauri is Related to the Effect
• On the origin of the helium-rich population in Omega Centauri
• Searching for merger debris in the Galactic halo: Chemodynamical evidence based on local blue HB stars
• Could Segue 1 be a destroyed star cluster? - a dynamical perspective
• The formation of compact dwarf ellipticals through merging star clusters
• A new formation model for omega Centauri: the crossroad of astrophysical processes
• On the Origin of the Kinematical Differences Between the Stellar Halo and the Old Globular Cluster System in the Large Magellanic Cloud
• The Globular Cluster Content of Maffei 1
• On the possible generation of the young massive open clusters Stephenson2 and BDSB122 by Omega Centauri
• On the Kinematics of Tidal Debris from Omega Cen's Progenitor Galaxy
• A Kinematically-Distinct RR-Lyrae Overdensity in the Inner Regions of the Milky Way
• Modelling the Canes Venatici I dwarf spheroidal galaxy
• Chemical abundances of field halo stars -- Implications for the building blocks of the Milky Way
• Search for Stellar Streams Based on Data from the RAVE5 and Gaia TGAS Catalogues