Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars
Name
1902.10611.pdf
Description
Accepted version
Size
940.24 KB
Format
Adobe PDF
Checksum (MD5)
cef3507a3553cab30444b6a8453c9def
Author(s)
Frebel, Anna L.
Date Issued
February 2019
Journal
Monthly Notices of the Royal Astronomical Society
Publisher
Oxford University Press (OUP)
Citation
Marino, A. F. et al. “Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars.” Monthly Notices of the Royal Astronomical Society, 485, 4 (February 2019) © 2019 The Author(s)
Version
Author's final manuscript
Abstract
We present results from the analysis of high-resolution spectra obtained with the Keck HIRES spectrograph for a sample of 17 candidate extremely metal-poor (EMP) stars originally selected from commissioning data obtained with the SkyMapper telescope. Fourteen of the stars have not been observed previously at high dispersion. Three have [Fe/H] ≤ −3.0, while the remainder, with two more metal-rich exceptions, have −3.0 ≤ [Fe/H] ≤ −2.0 dex. Apart from Fe, we also derive abundances for the elements C, N, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Co, Ni, and Zn, and for n-capture elements Sr, Ba, and Eu. None of the current sample of stars is found to be carbon-rich. In general, our chemical abundances follow previous trends found in the literature, although we note that two of the most metal-poor stars show very low [Ba/Fe] (∼−1.7) coupled with low [Sr/Ba] (∼−0.3). Such stars are relatively rare in the Galactic halo. One further star, and possibly two others, meet the criteria for classification as a r-I star. This study, together with that of Jacobson et al. (2015), completes the outcomes of the SkyMapper commissioning data survey for EMP stars.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1093/MNRAS/STZ645
