相关论文: Telling the tale of the first stars
The chemically most primitive stars provide constraints on the nature of the first stellar objects that formed in the Universe; elements other than hydrogen, helium and traces of lithium within these objects were generated by…
We elaborate the binary scenario for the origin of HE0107-5240, the most metal-poor star yet observed ([Fe/H] = -5.3), using current knowledge of the evolution of extremely metal-poor stars. From the observed C/N value, we estimate the…
We discuss the origin of HE0107-5240 which is the most metal poor star yet observed ([Fe/H] = -5.3). Its discovery has an important bearing on the question of the observability of "first generation" stars. In common with other metal-poor…
The external pollution of the first stars in the Galaxy is investigated. The first stars were born in clouds composed of the pristine gas without heavy elements. These stars accreted gas polluted with heavy elements while they still…
Star forming galaxies represent a valuable tracer of cosmic history. Recent observational progress with Hubble Space Telescope has led to the discovery and study of the earliest-known galaxies corresponding to a period when the Universe was…
The chemical composition of stars with extremely low metal contents (taking ``metals'' to mean all elements other than hydrogen and helium) provides us with information on the masses of the stars that produced the first metals. Such a…
Observations made using large ground-based and space-borne telescopes have probed cosmic history all the way from the present-day to a time when the Universe was less than a tenth of its present age. Earlier on lies the remaining frontier,…
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…
A prediction of standard inflationary cosmology is that the elemental composition of the medium out of which the earliest stars and galaxies condensed consisted primarily of hydrogen and helium 4He with small admixtures of deuterium,…
The first eight elements of the periodic table are discussed: H, He, Li, Be, B, C, N, and O. They are referred to as key elements, given their important role in stellar evolution. It is noteworthy that all of them were initially synthesized…
In this review, I survey our current understanding of how the very first stars in the universe formed, with a focus on three main areas of interest: the formation of the first protogalaxies and the cooling of gas within them, the nature and…
The basic processes of the formation of the first stars in the primordial Universe are outlined and the implications for cosmological structure formation discussed. By employing theoretical and numerical models of cosmic structure evolution…
We show that the "puzzling" chemical composition observed in the extremely metal poor star HE0107-5240 may be naturally explained by the concurrent pollution of at least two supernovae. In the simplest possible model a supernova of quite…
An impressive bulk of multiple astronomical observations indicates that there are plenty of objects in the universe with the age which cannot be explained by the conventional theory. A model is considered which successfully describes all…
The Era of the First Stars is one of the last unknown frontiers for exploration: a poorly understood billion years missing from our cosmological timeline. We have now developed several methods for finally filling in the lost billion years…
Two alternative scenarios concerning the origin and evolution of extremely metal-poor halo stars are investigated. The first one assumes that the stars have been completely metal-free initially and produced observed carbon and nitrogen…
We report a detailed abundance analysis for HE0107-5240, a halo giant with [Fe/H]_NLTE=-5.3. This star was discovered in the course of follow-up medium-resolution spectroscopy of extremely metal-poor candidates selected from the digitized…
The earliest stars to form in the Universe were the first sources of light, heat and metals after the Big Bang. The products of their evolution will have had a profound impact on subsequent generations of stars. Recent studies of primordial…
Recent observations of hydrogen absorption that occurred when the first stars turned on may give insights into the nature of dark matter.
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…