| Full text | |
| Author(s): |
Fernandez-Trincado, Jose G.
[1, 2, 3]
;
Beers, Timothy C.
[4, 5]
;
Tang, Baitian
[6]
;
Moreno, Edmundo
[7]
;
Perez-Villegas, Angeles
[8]
;
Ortigoza-Urdaneta, Mario
[2]
Total Authors: 6
|
| Affiliation: | [1] Univ Concepcion, Dept Astron, Casilla 160-C, Concepcion - Chile
[2] Univ Atacama, Inst Astron & Ciencias Planetarias, Copiapo - Chile
[3] Univ Bourgogne Franche Comte, Inst Utinam, CNRS, UMR6213, OSU, THETA, Observ Besancon, BP 1615, F-25010 Besancon - France
[4] Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 - USA
[5] Univ Notre Dame, JINA Ctr Evolut Elements, Notre Dame, IN 46556 - USA
[6] Sun Yat Sen Univ, Sch Phys & Astron, Zhuhai 519082 - Peoples R China
[7] Univ Nacl Autonoma Mexico, Inst Astron, Apdo Postal 70264, Mexico City 04510, DF - Mexico
[8] Univ Sao Paulo, IAG, Rua Matao 1226, Cidade Univ, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 8
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 488, n. 2, p. 2864-2880, SEP 2019. |
| Web of Science Citations: | 0 |
| Abstract | |
The latest edition of the APOGEE-2/DR14 survey catalogue and the first Payne data release of APOGEE abundance determinations by Ting et al. are examined. We identify 31 previously unremarked metal-poor giant stars with anomalously high levels of {[}N/Fe] abundances, which is not usually observed among metal-poor stars in the Milky Way. We made use of the Brussels Automatic Stellar Parameter (BACCHUS) code to re-derive manually the chemical abundances of 31 field stars in order to compile the main element families, namely the light elements (C,N), a-elements (O, Mg, Si), iron-peak element (Fe), s-process elements (Ce, Nd), and the light odd-Z element (Na, Al). We have found all these objects have a {[}N/Fe] greater than or similar to +0.5, and are thus identified here as nitrogen-rich stars. An orbital analysis of these objects revealed that a handful of them shares the orbital properties of the bar/bulge, and possibly linked to tidal debris of surviving globular clusters trapped into the bar component. Three of the 31 stars are actually halo interlopers into the bulge area, which suggests that halo contamination is not insignificant when studying N-rich stars found in the inner Galaxy, whereas the rest of the N-rich stars share orbital properties with the halo population. Most of the newly identified population exhibits chemistry similar to the so-called second-generation globular cluster stars (enriched in aluminum, {[}Al/Fe] greater than or similar to +0.5), whereas a handful of them exhibit lower abundances of aluminum, {[}Al/Fe] < +0.5, which are thought to be chemically associated with the first generation of stars, as seen in globular clusters, or compatible with origin from a tidally disrupted dwarf galaxy. (AU) | |
| FAPESP's process: | 17/15893-1 - Globular cluster orbits of bulge: the formation and evolution of the Milky Way |
| Grantee: | Maria de Los Angeles Perez Villegas |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |