BRIGHT METAL-POOR STARS FROM THE HAMBURG/ESO SURVEY. II. A CHEMODYNAMICAL ANALYSIS
We obtain estimates of stellar atmospheric parameters for a previously published sample of 1777 relatively bright (9 < B <14) metal-poor candidates from the Hamburg/ESO Survey. The original Frebel et al. analysis of these stars was able to derive estimates of [Fe/H] and [C/Fe] only for a subse...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | en_US |
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IOP Publishing
2017
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| Online Access: | http://hdl.handle.net/1721.1/109482 https://orcid.org/0000-0002-2139-7145 |
| _version_ | 1811096790120792064 |
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| author | Beers, Timothy C. Placco, Vinicius M. Carollo, Daniela Rossi, Silvia Lee, Young Sun Norris, John E. Dietz, Sarah Masseron, Thomas Frebel, Anna L. |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Beers, Timothy C. Placco, Vinicius M. Carollo, Daniela Rossi, Silvia Lee, Young Sun Norris, John E. Dietz, Sarah Masseron, Thomas Frebel, Anna L. |
| author_sort | Beers, Timothy C. |
| collection | MIT |
| description | We obtain estimates of stellar atmospheric parameters for a previously published sample of 1777 relatively bright (9 < B <14) metal-poor candidates from the Hamburg/ESO Survey. The original Frebel et al. analysis of these stars was able to derive estimates of [Fe/H] and [C/Fe] only for a subset of the sample, due to limitations in the methodology then available. A new spectroscopic analysis pipeline has been used to obtain estimates of T[subscript eff], log, g, [Fe/H], and [C/Fe] for almost the entire data set. This sample is very local—about 90% of the stars are located within 0.5 kpc of the Sun. We consider the chemodynamical properties of these stars in concert with a similarly local sample of stars from a recent analysis of the Bidelman and MacConnell "weak metal" candidates by Beers et al. We use this combined sample to identify possible members of the halo stream of stars suggested by Helmi et al. and Chiba & Beers, as well as stars that may be associated with stripped debris from the putative parent dwarf of the globular cluster Omega Centauri, suggested to exist by previous authors. We identify a clear increase in the cumulative frequency of carbon-enhanced metal-poor (CEMP) stars with declining metallicity, as well as an increase in the fraction of CEMP stars with distance from the Galactic plane, consistent with previous results. We also identify a relatively large number of CEMP stars with kinematics consistent with the metal-weak thick-disk population, with possible implications for its origin. |
| first_indexed | 2024-09-23T16:49:02Z |
| format | Article |
| id | mit-1721.1/109482 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T16:49:02Z |
| publishDate | 2017 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1094822022-10-03T08:31:11Z BRIGHT METAL-POOR STARS FROM THE HAMBURG/ESO SURVEY. II. A CHEMODYNAMICAL ANALYSIS Beers, Timothy C. Placco, Vinicius M. Carollo, Daniela Rossi, Silvia Lee, Young Sun Norris, John E. Dietz, Sarah Masseron, Thomas Frebel, Anna L. Massachusetts Institute of Technology. Department of Physics MIT Kavli Institute for Astrophysics and Space Research Frebel, Anna L. We obtain estimates of stellar atmospheric parameters for a previously published sample of 1777 relatively bright (9 < B <14) metal-poor candidates from the Hamburg/ESO Survey. The original Frebel et al. analysis of these stars was able to derive estimates of [Fe/H] and [C/Fe] only for a subset of the sample, due to limitations in the methodology then available. A new spectroscopic analysis pipeline has been used to obtain estimates of T[subscript eff], log, g, [Fe/H], and [C/Fe] for almost the entire data set. This sample is very local—about 90% of the stars are located within 0.5 kpc of the Sun. We consider the chemodynamical properties of these stars in concert with a similarly local sample of stars from a recent analysis of the Bidelman and MacConnell "weak metal" candidates by Beers et al. We use this combined sample to identify possible members of the halo stream of stars suggested by Helmi et al. and Chiba & Beers, as well as stars that may be associated with stripped debris from the putative parent dwarf of the globular cluster Omega Centauri, suggested to exist by previous authors. We identify a clear increase in the cumulative frequency of carbon-enhanced metal-poor (CEMP) stars with declining metallicity, as well as an increase in the fraction of CEMP stars with distance from the Galactic plane, consistent with previous results. We also identify a relatively large number of CEMP stars with kinematics consistent with the metal-weak thick-disk population, with possible implications for its origin. National Science Foundation (U.S.) (CAREER Grant AST 12-55160) Massachusetts Institute of Technology. Silverman (1968) Family Career Development Professorship 2017-05-31T20:53:58Z 2017-05-31T20:53:58Z 2016-11 2017-01 Article http://purl.org/eprint/type/JournalArticle 1538-4357 0004-637X http://hdl.handle.net/1721.1/109482 Beers, Timothy C. et al. “BRIGHT METAL-POOR STARS FROM THE HAMBURG/ESO SURVEY. II. A CHEMODYNAMICAL ANALYSIS.” The Astrophysical Journal 835.1 (2017): 81. © 2017 The American Astronomical Societ https://orcid.org/0000-0002-2139-7145 en_US http://dx.doi.org/10.3847/1538-4357/835/1/81 The Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing IOP Publishing |
| spellingShingle | Beers, Timothy C. Placco, Vinicius M. Carollo, Daniela Rossi, Silvia Lee, Young Sun Norris, John E. Dietz, Sarah Masseron, Thomas Frebel, Anna L. BRIGHT METAL-POOR STARS FROM THE HAMBURG/ESO SURVEY. II. A CHEMODYNAMICAL ANALYSIS |
| title | BRIGHT METAL-POOR STARS FROM THE HAMBURG/ESO SURVEY. II. A CHEMODYNAMICAL ANALYSIS |
| title_full | BRIGHT METAL-POOR STARS FROM THE HAMBURG/ESO SURVEY. II. A CHEMODYNAMICAL ANALYSIS |
| title_fullStr | BRIGHT METAL-POOR STARS FROM THE HAMBURG/ESO SURVEY. II. A CHEMODYNAMICAL ANALYSIS |
| title_full_unstemmed | BRIGHT METAL-POOR STARS FROM THE HAMBURG/ESO SURVEY. II. A CHEMODYNAMICAL ANALYSIS |
| title_short | BRIGHT METAL-POOR STARS FROM THE HAMBURG/ESO SURVEY. II. A CHEMODYNAMICAL ANALYSIS |
| title_sort | bright metal poor stars from the hamburg eso survey ii a chemodynamical analysis |
| url | http://hdl.handle.net/1721.1/109482 https://orcid.org/0000-0002-2139-7145 |
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