Work

Exploring Halo Substructure with Giant Stars: Spectroscopy of Stars in the Galactic Anticenter Stellar Structure

Year: 2003

Type: article

Abstract: To determine the nature of the recently discovered, ringlike stellar structure at the Galactic anticenter, we have collected spectra of a set of presumed constituent M giants selected from the Two Micron All Sky Survey Point Source Catalog. Radial velocities have been obtained for stars spanning ~100°, exhibiting a trend in velocity with Galactic longitude and an estimated dispersion of σ v = 20 ± 4 km s -1 . A mean metallicity [Fe/H] = -0.4 ± 0.3 measured for these stars combines with previous evidence from the literature to suggest a population with a significant metallicity spread. In addition, a curious alignment of at least four globular clusters of lower mean metallicity is noted to be spatially and kinematically consistent with this stellar distribution. We interpret the M giant sample position and velocity variation with Galactic longitude as suggestive of a satellite galaxy currently undergoing tidal disruption in a noncircular, prograde orbit about the Milky Way.

Source: The Astrophysical Journal

DOI: 10.1086/378767

Authors: Jeffrey D. Crane, Steven R. Majewski, Helio J. Rocha-Pinto, Peter M. Frinchaboy, Michael F. Skrutskie, David R. Law

Institutions: Association of Universities for Research in Astronomy, Kitt Peak National Observatory, University of Virginia

Language: English

Topic: Stellar, planetary, and galactic studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: National Science Foundation, National Aeronautics and Space Administration, California Institute of Technology

OpenAlex ID: W2049356611

FWCI: 7.913

Cites: 26

Cited by: 144

Related to: 10