Selecting Sagittarius

Identification and chemical characterization of the Sagittarius stream

E. A. Hyde, S. Keller, D. B. Zucker, R. Ibata, A. Siebert, G. F. Lewis, J. Penarrubia, M. Irwin, G. Gilmore, R. R. Lane, A. Koch, A. R. Conn, F. I. Diakogiannis, S. Martell

Research output: Contribution to journalArticle

12 Citations (Scopus)
5 Downloads (Pure)

Abstract

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.

Original languageEnglish
Article number189
Pages (from-to)1-13
Number of pages13
JournalAstrophysical Journal
Volume805
Issue number2
DOIs
Publication statusPublished - 1 Jun 2015

Bibliographical note

Copyright 2015 The American Astronomical Society. First published in the Astrophysical journal, 805(2), 189, 2015, published by IOP Publishing. The original publication is available at http://www.doi.org/10.1088/0004-637X/805/2/189. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

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