相关论文: Metal-free galaxy candidates discovered in CLASH
We study the clustering properties of the first galaxies formed in the Universe. We find that, due to chemical enrichment of the inter-stellar medium by isolated Population III stars formed in mini-halos at redshift z>30, the…
Star formation from metal-free gas, the hallmark of the first generation of Population III stars, was long assumed to occur only in the very early Universe. We report the discovery of MPG-CR3 (Metal-Pristine Galaxy COSMOS Redshift 3;…
Population III galaxies are predicted to exist at high redshifts and may be rendered sufficiently bright for detection with current telescopes when gravitationally lensed by a foreground galaxy cluster. Population III galaxies that exhibit…
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…
A small fraction of the atomic-cooling halos assembling at z<15 may form out of minihalos that never experienced any prior star formation, and could in principle host small galaxies of chemically unenriched stars. Since the prospects of…
The character of the first galaxies at redshifts z > 10 strongly depends on their level of pre-enrichment, which is in turn determined by the rate of primordial star formation prior to their assembly. In order for the first galaxies to…
Observing Population III (hereafter PopIII) galaxies, the hosts of first-generation stars, remains challenging even with the JWST. The current few candidates have been identified through the combination of a prominent HeII emission and the…
Clusters of galaxies allow a direct estimate of the metallicity and metal production yield on the largest scale so far. It is argued that cluster metallicity ($\sim 1/3$ solar) should be taken as representative of the low-$z$ universe as a…
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…
By definition, Population III stars are metal-free, and their protostellar collapse is driven by molecular hydrogen cooling in the gas-phase, leading to large characteristic masses. Population II stars with lower characteristic masses form…
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…
Population III (or Pop. III) stars, the first stellar generation built up from metal-free primordial gas, first started to form at redshifts z ~ 30. They formed primarily in small dark matter halos with masses of a few million solar masses.…
The first stars, known as Population III (PopIII), produced the first heavy elements, thereby enriching their surrounding pristine gas. Previous detections of metals in intergalactic gas clouds, however, find a heavy element enrichment…
The deepest space and ground-based observations find metal-enriched galaxies at cosmic times when the Universe was <1 Gyr old. These stellar populations had to be preceded by the metal-free first stars, Population III. Recent cosmic…
Old, metal-poor globular clusters trace the formation and evolution of early-type galaxies. Their are the best probes, at low redshift, of the building-up of galaxy halos at high redshift. Their properties constrain the characteristics of…
We present a comprehensive chemical abundance analysis of five red giants and two horizontal branch (HB) stars towards the southern Galactic bulge, at (l,b)$\sim$(0$^{\rm o}$,-11$^{\rm o}$). Based on high-resolution spectroscopy obtained…
Extremely metal poor stars have been the focus of much recent attention owing to the expectation that their chemical abundances can shed light on the metal and dust yields of the earliest supernovae. We present our most realistic simulation…
The existence of galaxies with no heavy elements is a key prediction of cosmological models. So far no "zero-metallicity", or Population III, galaxies have been identified. Here, we report the identification of an extremely metal-poor…
The search for metal-free stars has so far been unsuccessful, proving that if there are surviving stars from the first generation, they are rare, they have been polluted, or we have been looking in the wrong place. To predict the likely…
Population III stars, the hypothetical first generation metal-free stars, have yet to be discovered. Even after three years of successful JWST operations, studies have shown that most galaxies identified to date at $z > 5$ exhibit a…