Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars
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 prev...
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| Format: | Article |
| Language: | English |
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Oxford University Press (OUP)
2020
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| Online Access: | https://hdl.handle.net/1721.1/128724 |
| _version_ | 1826217362284609536 |
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| author | Frebel, Anna L. |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Frebel, Anna L. |
| author_sort | Frebel, Anna L. |
| collection | MIT |
| description | 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. |
| first_indexed | 2024-09-23T17:02:27Z |
| format | Article |
| id | mit-1721.1/128724 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T17:02:27Z |
| publishDate | 2020 |
| publisher | Oxford University Press (OUP) |
| record_format | dspace |
| spelling | mit-1721.1/1287242022-09-29T23:14:53Z Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars Frebel, Anna L. Massachusetts Institute of Technology. Department of Physics 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. 2020-12-03T18:34:10Z 2020-12-03T18:34:10Z 2019-02 2020-10-23T13:36:55Z Article http://purl.org/eprint/type/JournalArticle 0035-8711 https://hdl.handle.net/1721.1/128724 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) en 10.1093/MNRAS/STZ645 Monthly Notices of the Royal Astronomical Society Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Oxford University Press (OUP) arXiv |
| spellingShingle | Frebel, Anna L. Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars |
| title | Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars |
| title_full | Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars |
| title_fullStr | Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars |
| title_full_unstemmed | Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars |
| title_short | Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars |
| title_sort | keck hires spectroscopy of skymapper commissioning survey candidate extremely metal poor stars |
| url | https://hdl.handle.net/1721.1/128724 |
| work_keys_str_mv | AT frebelannal keckhiresspectroscopyofskymappercommissioningsurveycandidateextremelymetalpoorstars |