SELECTING SAGITTARIUS: IDENTIFICATION AND CHEMICAL CHARACTERIZATION OF THE SAGITTARIUS STREAM
- University of Western Sydney, Locked Bag 1797, Penrith South DC, NSW 1797 (Australia)
- Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2601 (Australia)
- Macquarie University, Physics and Astronomy, NSW 2109 (Australia)
- Observatoire astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l’Université, F-67000 Strasbourg (France)
- Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006 (Australia)
- ROE, The University of Edinburgh, Institute for Astronomy, Edinburgh EH9 3HJ (United Kingdom)
- Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)
- Departamento de Astronomía Universidad de Concepción, Casilla 160 C, Concepción (Chile)
- Landessternwarte, Zentrum für Astronomie der Universität Heidelberg, Königstuhl 12, D-69117 Heidelberg (Germany)
- International Center for Radio Astronomy Research, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)
Wrapping around the Milky Way, the Sagittarius stream is the dominant substructure in the halo. Our statistical selection method has allowed us to identify 106 highly likely members of the Sagittarius stream. Spectroscopic analysis of metallicity and kinematics of all members provides us with a new mapping of the Sagittarius stream. We find correspondence between the velocity distribution of stream stars and those computed for a triaxial model of the Milky Way dark matter halo. The Sagittarius trailing arm exhibits a metallicity gradient, ranging from −0.59 to −0.97 dex over 142°. This is consistent with the scenario of tidal disruption from a progenitor dwarf galaxy that possessed an internal metallicity gradient. We note high metallicity dispersion in the leading arm, causing a lack of detectable gradient and possibly indicating orbital phase mixing. We additionally report on a potential detection of the Sextans dwarf spheroidal in our data.
- OSTI ID:
- 22522353
- Journal Information:
- Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 805; ISSN ASJOAB; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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