@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/ibi/8JMKD3MGP3W34P/3NAADHH",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}