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Heavy elements in galactic bulge stars

Grant number: 13/50361-0
Support type:Scholarships in Brazil - Post-Doctorate
Effective date (Start): November 01, 2013
Effective date (End): October 31, 2014
Field of knowledge:Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
Principal Investigator:Beatriz Leonor Silveira Barbuy
Grantee:Mathieu van der Swaelmen
Home Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
Associated research grant:10/50930-6 - Chemical evolution and galactic and extragalactic stellar populations, by means of spectroscopy and imaging, AP.TEM

Abstract

The aim is to obtain abundance ratios in individual stars of the Galactic bulge, including field and globular duster stars, in order to identify them to different stellar populations, and different bulge formation scenarios. Jhe sample consists of 800 bulge stars, with spectra obtained with the FLAMES spectrograph, including 55 stars observed with the UVES spectrograph, at a resolution of 55,000, and 800 stars observed with the GIRAFFE spectrograph, at a resolution of 22,000. The observations were earned out in 4 fields: Baade's Window (1=1.14º, b=4.2º), field at -6º (1=0.2º, b=06º), Blanco field (I=0o, b=-12º), and field near NGC 6553 (I=5.2º, b=-3º). The abundance determination will be performed through calculations of synthetic spectra, using the codes turbospectrum and pfant06. The elements to be analyzed are formed by neutron-capture, both in the s-process and the r-process This includes the elements Ytrium, Strontium, Zirconium, Lantanum, Barium, formed dominantly in the s-process, and Europium, formed dominantly in the r-process. Spedal attention will be given to metal-poor stars, with metallicities around [Fe/H]~-1.0, in order to verify if they show excesses of s-elements, similarly to the globular duster NGC 6522, as found Chiappini et at. (2011). The final objective is to understand the processes of bulge formation, and to know the characteristics of the first supemovae that enriched the Galactic bulge at early times. (AU)

Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
VAN DER SWAELMEN, M.; BARBUY, B.; HILL, V.; ZOCCALI, M.; MINNITI, D.; ORTOLANI, S.; GOMEZ, A. Heavy elements Ba, La, Ce, Nd, and Eu in 56 Galactic bulge red giants. Astronomy & Astrophysics, v. 586, FEB 2016. Web of Science Citations: 21.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.