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@MastersThesis{Corazza:2017:RoPoII,
               author = "Corazza, Lia Camargo",
                title = "The role of population II and III stars in the cosmic chemical 
                         evolution",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "2017",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "2017-02-21",
             keywords = "cosmic chemical evolution, structure formation, population III, 
                         population II, cosmology, evolu{\c{c}}{\~a}o qu{\'{\i}}mica 
                         c{\'o}smica, forma{\c{c}}{\~a}o de estruturas, 
                         popula{\c{c}}{\~a}o III, popula{\c{c}}{\~a}o II, cosmologia.",
             abstract = "In this work we present a semi-analytical Chemical Evolution Model 
                         in the Cosmological Framework for 11 elements, taking into account 
                         the evolution of Population III and II stars and the transition 
                         between metallicities Z = 0 and 10\$^{\−6}\$, 
                         10\$^{\−4}\$, 10\$^{\−3}\$, 
                         4.10\$^{\−3}\$, 8.10\$^{\−3}\$ and 
                         2.10\$^{\−2}\$ Z\$_{\odot}\$. We calculate the star 
                         formation rate in the framework of hierarchical structure 
                         formation (PEREIRA; MIRANDA, 2010) coupled with chemical evolution 
                         equations for Oxygen (\emph{O}), Iron (\emph{Fe}), Zinc 
                         (\emph{Zn}), Nickel (\emph{Ni}), Silicon (\emph{Si}), Magnesium 
                         (\emph{Mg}), Aluminum (\emph{Al}), Carbon (\emph{C}), Nitrogen 
                         (\emph{N}), Phosphorus (\emph{P}) and Sulphur (\emph{S}). The 
                         best results are reached when considering a Press-Schechter-like 
                         formalism, a Salpeter IMF (x = 1.35) and \emph{T}\$_{s}\$ = 
                         2Gyr as time-scale for star formation (VITTI, 2012). We compare 
                         data generated by the model with chemical abundances in the 
                         gas-phase from Damped Lyman-\$\alpha\$ Systems (DLAs). Zn is 
                         underabundant probably due to the lack of Hypernovae (HNe) yields 
                         in the code, while P and Ni are underabundant probably because 
                         Supernovae type Ia (SNe Ia) yields are not taken into account. Al 
                         and Mg are discussed to be underabundant because of chemical 
                         abundances measurement problems in DLAs (such as blending with the 
                         Ly-\$\alpha\$ Forest) while \emph{Fe} and \emph{Si} are 
                         thought to be overabundant because of dust depletion effects on 
                         these systems. \emph{C}, \emph{N} and \emph{O} are unexpectedly 
                         overabundant and although \emph{C} and \emph{O} are used as fuel 
                         in SNe Ia, this mechanism is probably not enough to remove 
                         significant amount of these elements from the Intergalactic Medium 
                         (IGM), leaving the possibility for further studies on the 
                         influence of Carbon-enhanced Metal-Poor stars (CEMPs), Carbon 
                         planets formation in the early Universe and the appearance of life 
                         on the Chemical Cosmic Evolution (LOEB, 2016). RESUMO: Neste 
                         trabalho apresentamos um modelo semi-anal{\'{\i}}tico de 
                         Evolu{\c{c}}{\~a}o Qu{\'{\i}}mica no Contexto Cosmol{\'o}gico 
                         para 11 elementos, considerando a evolu{\c{c}}{\~a}o das 
                         estrelas de Popula{\c{c}}{\~a}o III e II e a 
                         transi{\c{c}}{\~a}o entre as metalicidades Z = 0, 
                         10\$^{\−6}\$, 10\$^{\−4}\$, 
                         10\$^{\−3}\$, 4.10\$^{\−3}\$, 
                         8.10\$^{\−3}\$ e 2.10\$^{\−2}\$ 
                         Z\$_{\odot}\$. Calculamos a taxa de forma{\c{c}}{\~a}o 
                         estelar no cen{\'a}rio hier{\'a}rquico de forma{\c{c}}{\~a}o 
                         de estruturas (PEREIRA; MIRANDA, 2010) acoplado {\`a} 
                         equa{\c{c}}{\~o}es de evolu{\c{c}}{\~a}o qu{\'{\i}}mica para 
                         o Oxig{\^e}nio (\emph{O}), Ferro (\emph{Fe}), Zinco 
                         (\emph{Z}n), N{\'{\i}}quel (\emph{Ni}), Sil{\'{\i}}cio 
                         (\emph{Si}), Magn{\'e}sio (\emph{Mg}), Alum{\'{\i}}nio 
                         (\emph{Al}), Carbono (\emph{C}), Nitrog{\^e}nio (\emph{N}), 
                         F{\'o}sforo (\emph{P}) e Enxofre (\emph{S}). Os melhores 
                         resultados s{\~a}o atingidos considerando-se um formalismo do 
                         tipo Press-Schechter, uma fun{\c{c}}{\~a}o de massa inicial 
                         (IMF) do tipo Salpeter e \emph{T}\$_{s}\$ = 2Gyr para a escala 
                         de tempo da forma{\c{c}}{\~a}o estelar (VITTI, 2012). Comparamos 
                         os dados gerados pelo modelo com abund{\^a}ncias 
                         qu{\'{\i}}micas na fase do g{\'a}s de Damped 
                         Lyman-\$\alpha\$ Systems (DLAs). Resultados mostram 
                         subabund{\^a}ncia para o \emph{Zn} provavelmente pela falta de 
                         yields de Hypenovae no c{\'o}digo, enquanto \emph{P} e 
                         \emph{Ni} est{\~a}o subabundantes provavalmente pelo fato de que 
                         yields de Supernovar tipo Ia (SNe Ia) n{\~a}o s{\~a}o 
                         considerados. Devido {\`a} problemas em medidas de DLAs, (como 
                         por exemplo \${''}\$blendind\${''}\$ com as linhas da Floresta 
                         Ly-\$\alpha\$), \emph{Al} e \emph{Mg} est{\~a}o 
                         subabundantes enquanto \emph{Fe} e \emph{Si} est{\~a}o 
                         sobreabundantes probavelmente devido {\`a} influ{\^e}ncia de 
                         deple{\c{c}}{\~a}o por poeira na determina{\c{c}}{\~a}o das 
                         abund{\^a}ncias nos dados observacionais nos DLAs. \emph{C}, 
                         \emph{N} and \emph{O} aparecem inesperadamente sobreabundantes, 
                         e embora C e O sejam usados como combust{\'{\i}}vel em SNe Ia, 
                         esse mecanismo provavelmente n{\~a}o {\'e} suficiente para 
                         retirar quantidades significativas destes elementos do Meio 
                         Intergal{\'a}tico (IGM), abrindo a possibilidade para futuros 
                         estudos sobre a influ{\^e}ncia das Carbon-enhanced Metal-Poor 
                         stars (CEMPs), planetas de Carbono no Universo Primordial e do 
                         aparecimento de vida na Evolu{\c{c}}{\~a}o Qu{\'{\i}}mica 
                         C{\'o}smica (LOEB, 2016).",
            committee = "Carvalho, Reinaldo Ramos de (presidente) and Miranda, Oswaldo 
                         Duarte (orientador) and Souza, Carlos Alexandre Wuensche de 
                         (orientador) and Costa, Roberto Dell'Aglio Dias da and Krabbe, 
                         Angela Cristina",
           copyholder = "SID/SCD",
         englishtitle = "O papel das estrelas de popula{\c{c}}{\~a}o II e II na 
                         evolu{\c{c}}{\~a}o qu{\'{\i}}mica c{\'o}smica",
             language = "en",
                pages = "99",
                  ibi = "8JMKD3MGP3W34P/3NAADHH",
                  url = "http://urlib.net/rep/8JMKD3MGP3W34P/3NAADHH",
           targetfile = "publicacao.pdf",
        urlaccessdate = "23 nov. 2020"
}


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