Multi-element abundance measurements from medium-resolution spectra. II. Catalog of stars in milky way dwarf satellite galaxies

Evan N. Kirby, Puragra Guhathakurta, Joshua D. Simon, Marla C. Geha, Constance M. Rockosi, Christopher Sneden, Judith G. Cohen, Sangmo Tony Sohn, Steven R. Majewski, Michael Siegel

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Abstract

We present a catalog of Fe, Mg, Si, Ca, and Ti abundances for 2961 stars in eight dwarf satellite galaxies of the Milky Way (MW): Sculptor, Fornax, Leo I, Sextans, Leo II, Canes Venatici I, Ursa Minor, and Draco. For the purposes of validating our measurements, we also observed 445 red giants in MW globular clusters and 21 field red giants in the MW halo. Themeasurements are based on Keck/DEIMOS medium-resolution spectroscopy (MRS) combined with spectral synthesis. We estimate uncertainties in [Fe/H] by quantifying the dispersion of [Fe/H] measurements in a sample of stars inmonometallic globular clusters (GCs).We estimate uncertainties in Mg, Si, Ca, and Ti abundances by comparing to high-resolution spectroscopic abundances of the same stars. For this purpose, a sample of 132 stars with published high-resolution spectroscopy in GCs, the MW halo field, and dwarf galaxies has been observed with MRS. The standard deviations of the differences in [Fe/H] and ([α/Fe]) (the average of [Mg/Fe], [Si/Fe], [Ca/Fe], and [Ti/Fe]) between the two samples is 0.15 and 0.16, respectively. This catalog represents the largest sample of multi-element abundances in dwarf galaxies to date. The next papers in this series draw conclusions on the chemical evolution, gas dynamics, and star formation histories from the catalog presented here. The wide range of dwarf galaxy luminosity reveals the dependence of dwarf galaxy chemical evolution on galaxy stellar mass.

Original languageEnglish (US)
Pages (from-to)352-375
Number of pages24
JournalAstrophysical Journal, Supplement Series
Volume191
Issue number2
DOIs
StatePublished - Dec 1 2010

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All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Kirby, E. N., Guhathakurta, P., Simon, J. D., Geha, M. C., Rockosi, C. M., Sneden, C., Cohen, J. G., Sohn, S. T., Majewski, S. R., & Siegel, M. (2010). Multi-element abundance measurements from medium-resolution spectra. II. Catalog of stars in milky way dwarf satellite galaxies. Astrophysical Journal, Supplement Series, 191(2), 352-375. https://doi.org/10.1088/0067-0049/191/2/352