相关论文: Near-Field Cosmology with Metal-Poor Stars
The abundance patterns of the most metal-poor stars in the Galactic halo and small dwarf galaxies provide us with a wealth of information about the early Universe. In particular, these old survivors allow us to study the nature of the first…
The early chemical evolution of the Galaxy and the Universe is vital to our understanding of a host of astrophysical phenomena. Since the most metal-poor Galactic stars (with metallicities down to [Fe/H]\sim-5.5) are relics from the…
The abundance patterns of metal-poor stars provide us a wealth of chemical information about various stages of the chemical evolution of the Galaxy. In particular, these stars allow us to study the formation and evolution of the elements…
Metal-poor stars hold the key to our understanding of the origin of the elements and the chemical evolution of the Universe. This chapter describes the process of discovery of these rare stars, the manner in which their surface abundances…
The abundance patterns of metal-poor stars provide us a wealth of chemical information about various stages of cosmic chemical evolution. In particular, these stars allow us to study the formation and evolution of the elements, and the…
Metal-poor stars provide information on the characteristics and chemical evolution of the halo population of the Galaxy, the first epoch of star formation and Galaxy formation (not just locally but with relevance to high-redshift objects),…
The most metal-poor stars found in the Galaxy and in nearby galaxies are witnesses of the early evolution of the Universe. In a general picture in which we expect the metallicity to increase monotonically with time, as a result of the metal…
This paper presents theoretical star formation and chemical enrichment histories for the stellar halo of the Milky Way based on new chemodynamical modeling. The goal of this study is to assess the extent to which metal-poor stars in the…
Studying a range of old metal-poor stars provides information over cosmological timescales of our Galaxy. Such studies are indicative of the pristine gases and evolution of the Milky Way. Deriving stellar parameters and abundances from…
The first stars fundamentally transformed the early Universe through their production of energetic radiation and the first heavy chemical elements. The impact on cosmic evolution sensitively depends on their initial mass function (IMF),…
Metal-poor stars provide the fossil record of Galactic chemical evolution and the nucleosynthesis processes that took place at the earliest times in the history of our Galaxy. From detailed abundance studies of low mass, extremely…
The search for the first stars formed from metal-free gas in the universe is one of the key issues in astronomy because it relates to many fields, such as the formation of stars and galaxies, the evolution of the universe, and the origin of…
We use detailed nucleosynthesis calculations and a realistic prescription for the environment of the first stars to explore the first episodes of chemical enrichment that occurred during the dark ages. Based on these calculations, we…
The chemical composition of the most metal-deficient stars reflects the composition of the gas from which they formed. These old stars provide crucial clues to the star formation history and the synthesis of chemical elements in the early…
The chemical abundances of metal-poor stars provide a great deal of information regarding the individual nucleosynthetic processes that created the observed elements and the overall process of chemical enrichment of the galaxy since the…
Metal-poor stars in the Milky Way are local relics of the epoch of the first stars and the first galaxies. However, a low metallicity does not prove that a star formed in this ancient era, as metal-poor stars form over a range of redshift…
The massive First Stars (the first ones to contribute to the chemical enrichment of the Universe due to their short lifetimes) are long dead, and even though efforts to directly observe them in high redshift galaxies are underway, a step…
The first galaxies contain stars born out of gas with little or no metals. The lack of metals is expected to inhibit efficient gas cooling and star formation but this effect has yet to be observed in galaxies with oxygen abundance relative…
The first stars are predicted to have formed within 200 million years after the Big Bang, initiating the cosmic dawn. A true first star has not yet been discovered, although stars with tiny amounts of elements heavier than helium ('metals')…
The cosmic microwave background and the cosmic expansion can be interpreted as evidence that the Universe underwent an extremely hot and dense phase about 14 Gyr ago. The nucleosynthesis computations tell us that the Universe emerged from…