Related papers: Inefficient Star Formation In Extremely Metal Poor…
The extreme outer regions of disk galaxies, lying at or beyond the classical optical radius defined by R25, present an opportunity to study star formation and chemical evolution under unique physical conditions, possibly reminscent of those…
Theory predicts that cosmological gas accretion plays a fundamental role fuelling star formation in galaxies. However, a detailed description of the accretion process to be used when interpreting observations is still lacking. Using the…
The recent discovery of a hyper metal-poor (HMP) star, whose metallicity Fe/H is smaller than 1/100,000 of the solar ratio, together with one earlier HMP star, has raised a challenging question if these HMP stars are the actual first…
Gas inflow feeds galaxies with low metallicity gas from the cosmic web, sustaining star formation across the Hubble time. We make a connection between these inflows and metallicity inhomogeneities in star-forming galaxies, by using…
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…
Many studies concluded that magnetic fields suppress star formation in molecular clouds and Milky Way like galaxies. However, most of these studies are based on fully developed fields that have reached the saturation level, with little work…
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 present the first detection of molecular gas cooling CO emission lines from ordinary massive galaxies at z=1.5. Two sources were observed with the IRAM Plateau de Bure Interferometer, selected to lie in the mass-star formation rate…
How do stars manage to form within low-density, HI-dominated gas? Such environments provide a laboratory for studying star formation with physical conditions distinct from starbursts and the metal-rich disks of spiral galaxies where most…
We analyze resolved stellar near-infrared photometry of 21 HST fields in M31 to constrain the impact of metallicity on the formation of carbon stars. Observations of nearby galaxies show that the carbon stars are increasingly rare at higher…
We investigate the differential effects of metal cooling and galactic stellar winds on the cosmological formation of individual galaxies with three sets of cosmological, hydrodynamical zoom simulations of 45 halos in the mass range…
Metals are thought to have profound effects on the internal structures of molecular clouds in which stars are born. The absence of metals is expected to prevent gas from efficient cooling and fragmentation in theory. However, this effect…
We performed $42$ simulations of the first star formation with initial supersonic gas flows relative to the dark matter at the cosmic recombination era. Increasing the initial streaming velocities led to delayed halo formation and increased…
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…
We investigate the conditions under which the first low-mass stars formed in the universe by confronting theoretical predictions governing the transition from massive Population III to low-mass Population II stars with recent observational…
We study relations between stellar mass, star formation and gas-phase metallicity in a sample of 177,071 unique emission line galaxies from the SDSS-DR7, as well as in a sample of 43,767 star forming galaxies at z=0 from the cosmological…
We present first results concerning the metallicities and stellar populations of galaxies formed in a cosmologically motivated simulation. The calculations include dark matter, gas dynamics, radiation processes, star formation, supernovae…
We review recent theoretical results on the formation of the first stars in the universe, and emphasize related open questions. In particular, we discuss the initial conditions for Population III star formation, as given by variants of the…
Quiescent galaxies (QGs) typically have little cold gas to form stars. The discovery of gas-rich QGs challenges our conventional understanding of the evolutionary paths of galaxies. We take advantage of a new catalog of nearby, massive…
The first stars were born from chemically pristine gas. They were likely massive, and thus they rapidly exploded as supernovae, enriching the surrounding gas with the first heavy elements. In the Local Group, the chemical signatures of the…