Journal article
Discovery of a nitrogen-enhanced mildly metal-poor binary system: Possible evidence for pollution from an extinct AGB star
Astronomy and astrophysics (Berlin), Vol.631, p.A97
11/01/2019
DOI: 10.1051/0004-6361/201935369
Abstract
We report the serendipitous discovery of a nitrogen-rich, mildly metal-poor ([Fe/H] = -1.08) giant star in a single-lined spectroscopic binary system found in the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) survey, Data Release 14 (DR14). Previous work has assumed that two percent of halo giants with unusual elemental abundances have been evaporated from globular clusters, but other origins for their abundance signatures, including binary mass transfer, must also be explored. We present the results of an abundance reanalysis of the APOGEE-2 high-resolution near-infrared spectrum of 2M12451043+1217401 with the Brussels Automatic Stellar Parameter (BACCHUS) automated spectral analysis code. We manually re-derive the main element families, namely light elements (C, N), elements (O, Mg, Si), the iron-peak element (Fe), s-process element (Ce), and light odd-Z element (Al). Our analysis confirms the N-rich nature of 2M12451043+1217401, which has a [N/Fe] ratio of +0.69, and shows that the abundances of C and Al are slightly discrepant from those of a typical mildly metal-poor red giant branch star, but exhibit Mg, Si, O and s-process abundances (Ce) of typical field stars. We also detect a particularly large variability in the radial velocity of this star over the period of the APOGEE-2 observations; the most likely orbit fit to the radial velocity data has a period of 730.89 +/- 106.86 days, a velocity semi-amplitude of 9.92 +/- 0.14 km s(-1), and an eccentricity of similar to 0.1276 +/- 0.1174. These data support the hypothesis of a binary companion, which has probably been polluted by a now-extinct asymptotic giant branch star.
Details
- Title: Subtitle
- Discovery of a nitrogen-enhanced mildly metal-poor binary system: Possible evidence for pollution from an extinct AGB star
- Creators
- Jose G. Fernandez-Trincado - University of AtacamaRonald Mennickent - University of ConcepciónMauricio Cabezas - Acad Sci Czech Republ, Astron Inst, Bocni 2 1401-1, Prague 14100, Czech RepublicOlga Zamora - Universidad de La LagunaSarah L. Martell - UNSW SydneyTimothy C. Beers - University of Notre DameVinicius M. Placco - University of Notre DameDavid M. Nataf - Johns Hopkins UniversitySzabolcs Meszaros - Eötvös Loránd UniversityDante Minniti - Univ Andres Bello, Fac Ciencias Exactas, Dept Cs Fis, Av Fernandez Concha 700, Santiago, ChileDominik R. G. Schleicher - University of ConcepciónBaitian Tang - Sun Yat-sen UniversityAngeles Perez-Villegas - Univ Sao Paulo, IAG, Rua Matao 1226,Cidade Univ, BR-05508900 Sao Paulo, SP, BrazilAnnie C. Robin - Institut UTINAMCeline Reyl - Univ Bourgogne Franche Comte, Inst Utinam, UMR 6213, OSU THETA Franche Comte,Observ Besancon,CNRS, BP 1615, F-25010 Besancon, France
- Resource Type
- Journal article
- Publication Details
- Astronomy and astrophysics (Berlin), Vol.631, p.A97
- DOI
- 10.1051/0004-6361/201935369
- ISSN
- 0004-6361
- eISSN
- 1432-0746
- Publisher
- Edp Sciences S A
- Number of pages
- 12
- Grant note
- New York University Universidad Nacional Autonoma de Mexico Harvard-Smithsonian Center for Astrophysics; Smithsonian Institution AFB-170002 / Chilean Centro de Excelencia en Astrofisica y Tecnologias Afines (CATA) BASAL grant RVO 67985815 / Astronomical Institute of the Czech Academy of Sciences; Czech Academy of Sciences U1931102 / National Natural Science Foundation of China; National Natural Science Foundation of China (NSFC) 0101973 / Centre national d'etudes spatiales (CNES); Centre National D'etudes Spatiales Lawrence Berkeley National Laboratory; United States Department of Energy (DOE) 2017/15893-1 / FAPESP; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) Ohio State University
- Language
- English
- Date published
- 11/01/2019
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984701732102771
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