Signatures of star streams in the phase space distribution of nearby halo stars

Abstract

We have analyzed the phase space distribution of a sample of about 900 non--kinematically selected low metallicity stars in the solar vicinity. The stars primarily represent the thick disk and halo populations of the Milky Way. We aim to identify overdensely populated regions in phase space, which we interpret as signatures of star streams passing close to the Sun. The search was conducted in a space constructed from the angular momenta and eccentricities of the stellar orbits. Besides recovering all well known star streams in the thick disk, we isolated four statistically significant phase space overdensities amongst halo stars. One of them is associated with a previously known halo star stream, but three of them are novel features, which we propose be also considered as genuine halo streams.

arXiv comment6 pages, 5 figures, accepted by Astron. Astrophys

References in corpus (21)

• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: I. Morphology of the Sagittarius Core and Tidal Arms
• Local stellar kinematics from Hipparcos data
• The Field of Streams: Sagittarius and its Siblings
• Kinematics of Metal-Poor Stars in the Galaxy. III. Formation of the Stellar Halo and Thick Disk as Revealed from a Large Sample of Non-Kinematically Selected Stars
• Debris streams in the solar neighbourhood as relicts from the formation of the Milky Way
• The Effect of the Outer Lindblad Resonance of the Galactic Bar on the Local Stellar Velocity Distribution
• A Low Latitude Halo Stream around the Milky Way
• The Distribution of Nearby Stars in Velocity Space Inferred from Hipparcos Data
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: IV. Modeling the Sagittarius Tidal Tails
• Galactic Halo substructure in the Sloan Digital Sky Survey: the ancient tidal stream from the Sagittarius dwarf galaxy
• One Ring to Encompass them All: A giant stellar structure that surrounds the Galaxy
• Velocity trends in the debris of Sagittarius and the shape of the dark-matter halo of the Galaxy
• Kinematics of Metal-Poor Stars in the Galaxy. II. Proper Motions for a Large Non-Kinematically Selected Sample
• Pieces of the puzzle: Ancient substructure in the Galactic disk
• The Effect of Spiral Structure on the Stellar Velocity Distribution in the Solar Neighborhood
• Tracing out the Northern Tidal Stream of the Sagittarius Dwarf Spheoridal Galaxy
• Velocity distribution of stars in the solar neighbourhood
• The Extragalactic Origin of the Arcturus Group
• Fine structure in the phase space distribution of nearby subdwarfs
• The Virgo stellar over-density: Mapping the infall of the Sagittarius tidal stream onto the Milky Way disk
• Kinematics of Nearby Subdwarf Stars

Cited by in corpus (9)

• Characterizing the Chemistry of the Milky Way Stellar Halo: Detailed Chemical Analysis of a Metal-Poor Stellar Stream
• On the kinematic detection of accreted streams in the Gaia era: a cautionary tale
• On the age heterogeneity of the Pleiades, Hyades and Sirius moving groups
• Halo streams in the 7th SDSS data release
• Stellar halo streams in the Solar neighbourhood
• Evidence of tidal debris from Omega Cen in the Kapteyn Group
• Chemical Abundances of the Outer Halo Stars in the Milky Way
• Kinematically Detected Halo Streams
• Stellar substructures in the solar neighbourhood IV. Kinematic Group 1 in the Geneva-Copenhagen survey