相关论文: A Modified Initial Mass Function of the First Star…
We compare elemental abundance patterns of $\sim 200$ extremely metal-poor (EMP; [Fe/H]$<-3$) stars with supernova yields of metal-free stars in order to obtain insights into the characteristic masses of the first (Population III or Pop…
The nature of the first Pop III stars is still a mystery and the energy distribution of the first supernovae is completely unexplored. For the first time we account simultaneously for the unknown initial mass function (IMF), stellar mixing,…
Extremely metal-poor stars are uniquely informative on the nature of massive Population III stars. Modulo a few elements that vary with stellar evolution, the present-day photospheric abundances observed in extremely metal-poor stars are…
Recent studies suggest that the initial mass function (IMF) of the first stars was likely to be extremely top-heavy, unlike what is observed at present. We propose a scenario to generate fragmentation to lower masses once the first massive…
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),…
It has frequently been suggested that the stellar IMF in galaxies was top-heavy at early times. This would be plausible physically if the IMF depends on a mass scale such as the Jeans mass that was higher at earlier times because of the…
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 first generation of stars, Population III (Pop III), is believed to be massive, with some potentially having masses in the range 140 M$_\odot$ to 270 M$_\odot$ and capable of exploding as a pair-instability supernova (PISN). Such events…
We investigated a volume-limited sample of LAMOST main-sequence stars with masses from 0.25 to 1 $M_{\odot}$ and distances of 150-350 pc to explore how the stellar initial mass function (IMF) varies with metallicity. We corrected the…
The initial mass function (IMF) of the first (Population III) stars and Population II (Pop II) stars is poorly known due to a lack of observations of the period between recombination and reionization. In simulations of the formation of the…
The first stars are assumed to be predominantly massive. Although, due to the low initial abundances of heavy elements the line-driven stellar winds are supposed to be inefficient in the first stars, these stars may loose a significant…
We discuss the star formation history of the Galaxy, based on the observations of extremely metal-poor stars (EMP) in the Galactic halo, to gain an insight into the evolution and structure formation in the early universe. The initialmass…
We investigate whether a single population of first stars could have influenced both the metal enrichment and reionization of the high-redshift intergalactic medium (IGM), by calculating the generated ionizing radiation per unit metal yield…
The abundance patterns of extremely metal-poor stars preserve a fossil record of the Universe's earliest chemical enrichment by the supernova explosions from the evolution of first generation of stars, also referred to as Population III (or…
Recent observations by the James Webb Space Telescope (JWST) have found evidence for an invariant relation between stellar mass, metallicity, and star formation rate up to $z\sim 8$ and its breakdown at higher redshifts. Understanding the…
The first metal enrichment in the universe was made by supernova (SN) explosions of population (Pop) III stars. The trace remains in abundance patterns of extremely metal-poor (EMP) stars. We investigate the properties of nucleosynthesis in…
We investigate the intrinsic scatter in the chemical abundances of a sample of metal-poor ([Fe/H]<-2.5) Milky Way halo stars. We draw our sample from four historic surveys and focus our attention on the stellar Mg, Ca, Ni, and Fe…
The spectral absorption lines in early-type galaxies contain a wealth of information regarding the detailed abundance pattern, star formation history, and stellar initial mass function (IMF) of the underlying stellar population. Using our…
We exploit the recent observations of extremely metal-poor (EMP) stars in the Galactic halo and investigate the constraints on the IMF of the stellar population that left these low-mass survivors of [Fe/H]<-2.5 and the chemical evolution…
After the Big Bang nucleosynthesis, the first heavy element enrichment in the Universe was made by a supernova (SN) explosion of a population (Pop) III star (Pop III SN). The abundance ratios of elements produced from Pop III SNe are…