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Chemical evolution and galactic and extragalactic stellar populations, by means of spectroscopy and imaging

Grant number: 10/50930-6
Support type:Research Projects - Thematic Grants
Duration: January 01, 2011 - January 31, 2016
Field of knowledge:Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
Principal Investigator:Beatriz Leonor Silveira Barbuy
Grantee:Beatriz Leonor Silveira Barbuy
Home Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
Associated grant(s):13/50018-3 - Chemical evolution of galactic bulge and halo and star formation, AP.R
12/01242-5 - Searches for metal-poor stars from the Hamburg/ESO survey using the CH G band, PUB.ART
Associated scholarship(s):15/09482-3 - High-resolution spectroscopy of the metal-poor bulge globular cluster NGC 6558, BP.IC
13/08915-8 - Spectroscopy of galactic halo and bulge stars, BP.PD
13/50361-0 - Heavy elements in galactic bulge stars, BP.PD
+ associated scholarships 13/16924-7 - S-process in extremely metal-poor stars, BP.PD
11/03658-1 - Metallicity calibration of metal-poor sub-dwarf M stars based on binary companions, BP.MS
10/08996-0 - The Milky Way halo revisited, BP.PD - associated scholarships


Stellar populations are characterized by ages, metallicities, kinematical properties and location in the parent galaxy, and they are tracers of the formation and chemical and dynamical evolution of galaxies. They also bring evidences on processes of star formation and evolution. In this project we propose to develop new steps in our studies on stellar populations of the Milky Way, Magellanic Clouds and other nearby galaxies, as well as composite stellar populations of more distant galaxies observed in integrated light. Our work on stellar populations of the Milky Way involve samples of stars in the bulge, thick disk, internal and external halo, and thin disk, Individual stars are also observable in the Magellanic Clouds. In the Milky Way and Magellanic Clouds it is also useful to obtain imaging of star clusters, in different colours, aiming at deriving their colour-magnitude diagrams. The observation of integrated light of star clusters and distant galaxies can also be studied through deconvolution methods of their stellar populations. We look for ages, kinematical properties, metallicities, abundance ratios, among other parameters. A detailed analysis of star's chemical composititon can lead to evidences regarding epoch of star formation, and on the nucleosynthesis taking place in a previous, generation of massive stars, or else internal nucleosynthesis associated with convective mixing due to hydrodynamical mechanisms. The study of proto-stars and young stars completes the cycle of stellar populations found in galaxies. In our work we look for answers to the following general questions: processes of formation of the Galactic bulge, and implications, for the formation of spiral galaxies; processes of formation of globular clusters; identification of the oldest globular clusters, and search for evidences for its eventual formation in the proto-galaxy phase; evidences of nucleosynthesis having taken place in the Big-Bang and in the first generations of stars, and its implications for the processes of formation of the first objects in the Universe. (AU)

Articles published in Agência FAPESP Newsletter about the research grant
Scientists investigate oldest stars in the Milky Way 

Scientific publications (12)
(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)
SANTOS-SILVA, T.; GREGORIO-HETEM, J.; MONTMERLE, T.; FERNANDES, B.; STELZER, B. Star formation history of Canis Major OB1 II. A bimodal X-ray population revealed by XMM-Newton. Astronomy & Astrophysics, v. 609, FEB 1 2018. Web of Science Citations: 1.
YONG, DAVID; CASAGRANDE, LUCA; VENN, KIM A.; CHENE, ANDRE-NICOLAS; KEOWN, JARED; MALO, LISON; MARTIOLI, EDER; ALVES-BRITO, ALAN; ASPLUND, MARTIN; DOTTER, AARON; MARTELL, SARAH L.; MELENDEZ, JORGE; SCHLESINGER, KATHARINE J. GRACES observations of young [alpha/Fe]-rich stars. Monthly Notices of the Royal Astronomical Society, v. 459, n. 1, p. 487-495, JUN 11 2016. Web of Science Citations: 21.
REGGIANI, HENRIQUE; MELENDEZ, JORGE; YONG, DAVID; RAMIREZ, IVAN; ASPLUND, MARTIN. First high-precision differential abundance analysis of extremely metal-poor stars. Astronomy & Astrophysics, v. 586, FEB 2016. Web of Science Citations: 8.
MELENDEZ, JORGE; PLACCO, VINICIUS M.; TUCCI-MAIA, MARCELO; RAMIREZ, IVAN; LI, TING S.; PEREZ, GABRIEL. 2MASS J18082002-5104378: The brightest (V=11.9) ultra metal-poor star. Astronomy & Astrophysics, v. 585, JAN 2016. Web of Science Citations: 7.
GREGORIO-HETEM, J.; HETEM, A.; SANTOS-SILVA, T.; FERNANDES, B. Statistical fractal analysis of 25 young star clusters. Monthly Notices of the Royal Astronomical Society, v. 448, n. 3, p. 2504-2513, APR 11 2015. Web of Science Citations: 13.
FERNANDES, B.; GREGORIO-HETEM, J.; MONTMERLE, T.; ROJAS, G. Spectroscopic characterization of X-ray emitting young stars associated with the Sh 2-296 nebula. Monthly Notices of the Royal Astronomical Society, v. 448, n. 1, p. 119-134, MAR 21 2015. Web of Science Citations: 2.
THYGESEN, A. O.; SBORDONE, L.; ANDRIEVSKY, S.; KOROTIN, S.; YONG, D.; ZAGGIA, S.; LUDWIG, H. -G.; COLLET, R.; ASPLUND, M.; VENTURA, P.; D'ANTONA, F.; MELENDEZ, J.; D'ERCOLE, A. The chemical composition of red giants in 47 Tucanae I. Fundamental parameters and chemical abundance patterns. Astronomy & Astrophysics, v. 572, DEC 2014. Web of Science Citations: 24.
BENSBY, T.; YEE, J. C.; FELTZING, S.; JOHNSON, J. A.; GOULD, A.; COHEN, J. G.; ASPLUND, M.; MELENDEZ, J.; LUCATELLO, S.; HAN, C.; THOMPSON, I.; GAL-YAM, A.; UDALSKI, A.; BENNETT, D. P.; BOND, I. A.; KOHEI, W.; SUMI, T.; SUZUKI, D.; SUZUKI, K.; TAKINO, S.; TRISTRAM, P.; YAMAI, N.; YONEHARA, A. Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars V. Evidence for a wide age distribution and a complex MDF. Astronomy & Astrophysics, v. 549, JAN 2013. Web of Science Citations: 231.
ALVES-BRITO, A.; YONG, D.; MELENDEZ, J.; VASQUEZ, S.; KARAKAS, A. I. CNO and F abundances in the globular cluster M22 (NGC 6656). Astronomy & Astrophysics, v. 540, APR 2012. Web of Science Citations: 32.
ALVES-BRITO, A.; KARAKAS, A. I.; YONG, D.; MELENDEZ, J.; VASQUEZ, S. CNO and F abundances in the barium star HD 123396. Astronomy & Astrophysics, v. 536, DEC 2011. Web of Science Citations: 12.
BENSBY, T.; ADEN, D.; MELENDEZ, J.; GOULD, A.; FELTZING, S.; ASPLUND, M.; JOHNSON, J. A.; LUCATELLO, S.; YEE, J. C.; RAMIREZ, I.; COHEN, J. G.; THOMPSON, I.; BOND, I. A.; GAL-YAM, A.; HAN, C.; SUMI, T.; SUZUKI, D.; WADA, K.; MIYAKE, N.; FURUSAWA, K.; OHMORI, K.; SAITO, TO.; TRISTRAM, P.; BENNETT, D. Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars IV. Two bulge populations. Astronomy & Astrophysics, v. 533, SEP 2011. Web of Science Citations: 125.

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