Observational Properties of Primordial Stellar Populations
نویسنده
چکیده
We present the first results of a study of the expected properties of the first stellar generations in the Universe. In particular, we consider and discuss a series of properties that, on the basis of the emission from associated HII regions, permit one to discern bona fide primeval stellar generations from the ones formed after pollution from supernova explosions. The expected performance of NGST for the study and the characterization of primordial sources is also discussed.
منابع مشابه
Stellar Populations in the Central Galaxies of Fossil Groups
It is inferred from the symmetrical and luminous X-ray emission of fossil groups that they are mature, relaxed galaxy systems. Cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. Recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (BGGs), the central early-t...
متن کاملStellar Populations , Butcher - Oemler Effect , Star Formation in Clusters Bianca
In this brief overview of the stellar populations of galaxies in clusters I highlight some of the most recent results, including the downsizing of the k+a population and the star formation–local density relation. I conclude discussing some open questions regarding the interpretation of the observational results, and speculating on the current meaning of the words “primordial” and “environmental”.
متن کاملTwo populations of metal-free stars in the early Universe
We construct star formation histories at redshifts z & 5 for two physically distinct populations of primordial, metal-free stars, motivated by theoretical and observational arguments that have hinted towards the existence of an intermediate stellar generation between Population III and Population I/II. Taking into account the cosmological parameters as recently revised by WMAP after three years...
متن کاملA Hypothesis for the Color Bimodality of Jupiter Trojans
One of the most enigmatic and hitherto unexplained properties of Jupiter Trojans is their bimodal color distribution. This bimodality is indicative of two sub-populations within the Trojans, which have distinct size distributions. In this paper, we present a simple, plausible hypothesis for the origin and evolution of the two Trojan color sub-populations. In the framework of dynamical instabili...
متن کاملThe Smallest AGN Host Galaxies
We describe our efforts to study dwarf galaxies with active nuclei, whose black holes, with masses ≤ 106 M⊙, provide the best current observational constraints on the mass distribution of primordial seed black holes. Although these low-mass galaxies do not necessarily contain classical bulges, Barth, Greene, & Ho (2005) show that their stellar velocity dispersions and black hole masses obey the...
متن کامل