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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

TheR-Process Alliance: First Magellan/MIKE Release from the Southern Search forR-process-enhanced Stars{*}

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Autor(es):
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Ezzeddine, Rana [1, 2, 3, 4] ; Rasmussen, Kaitlin [5, 3] ; Frebel, Anna [1, 2, 3] ; Chiti, Anirudh [1, 2, 3] ; Hinojisa, Karina [1, 2] ; Placco, Vinicius M. [5, 3] ; Ji, Alexander P. [6, 3] ; Beers, Timothy C. [5, 3] ; Hansen, Terese T. [7, 8] ; Roederer, Ian U. [9, 3] ; Sakari, Charli M. [10] ; Melendez, Jorge [11]
Número total de Autores: 12
Afiliação do(s) autor(es):
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[1] MIT, Dept Phys, Cambridge, MA 02139 - USA
[2] MIT, Kavli Inst Astrophys & Space Res, 77 Massachusetts Ave, Cambridge, MA 02139 - USA
[3] Ctr Evolut Elements, Joint Inst Nucl Astrophys, Washington, DC 20004 - USA
[4] Univ Florida, Bryant Space Sci Ctr, Dept Astron, Gainesville, FL 32611 - USA
[5] Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 - USA
[6] Observ Carnegie Inst Sci, 813 Santa Barbara St, Pasadena, CA 91101 - USA
[7] Texas A&M Univ, Dept Phys & Astron, College Stn, TX 77843 - USA
[8] Texas A&M Univ, Mitchell Inst Fundamental Phys & Astron, College Stn, TX 77843 - USA
[9] Univ Michigan, Dept Astron, Ann Arbor, MI 48109 - USA
[10] Univ Washington, Dept Astron, Seattle, WA 98195 - USA
[11] Univ Sdo Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508900 Sao Paulo, SP - Brazil
Número total de Afiliações: 11
Tipo de documento: Artigo Científico
Fonte: ASTROPHYSICAL JOURNAL; v. 898, n. 2 AUG 2020.
Citações Web of Science: 0
Resumo

Extensive progress has recently been made in our understanding of heavy-element production via ther-process in the universe, specifically with the first observed neutron star binary merger (NSBM) event associated with the gravitational-wave signal detected by LIGO, GW170817. The chemical abundance patterns of metal-poorr-process-enhanced stars provide key evidence for the dominant site(s) of ther-process and whether NSBMs are sufficiently frequent or prolificr-process sources to be responsible for the majority ofr-process material in the universe. We present atmospheric stellar parameters (using a nonlocal thermodynamic equilibrium analysis) and abundances from a detailed analysis of 141 metal-poor stars carried out as part of theR-Process Alliance (RPA) effort. We obtained high-resolution ``snapshot{''} spectroscopy of the stars using the MIKE spectrograph on the 6.5 m Magellan Clay telescope at Las Campanas Observatory in Chile. We find 10 new highly enhancedr-II (with {[}Eu/Fe] > +1.0), 62 new moderately enhancedr-I (+0.3 < {[}Eu/Fe] <= +1.0), and 17 new limited-r({[}Eu/Fe] < +0.3) stars. Among those, we find 17 new carbon-enhanced metal-poor (CEMP) stars, of which five are CEMP-no. We also identify one news-process-enhanced ({[}Ba/Eu] > +0.5) and five newr/s(0.0 < {[}Ba/Eu] < +0.5) stars. In the process, we discover a new ultra-metal-poor (UMP) star at {[}Fe/H] = -4.02. One of ther-II stars shows a deficit in alpha and Fe-peak elements, typical of dwarf galaxy stars. Our search forr-process-enhanced stars by RPA efforts has already roughly doubled the knownr-process sample. (AU)

Processo FAPESP: 14/18100-4 - Populações estelares na Via Láctea: bojo, halo, disco e regiões de formação de estrelas; instrumentação para espectroscopia de alta resolução
Beneficiário:Beatriz Leonor Silveira Barbuy
Linha de fomento: Auxílio à Pesquisa - Temático