Related papers: Low-metallicity (sub-SMC) massive stars
The abundance patterns of metal-poor stars provide us a wealth of chemical information about various stages of the chemical evolution of the Galaxy. In particular, these stars allow us to study the formation and evolution of the elements…
We present the first robust measurement of the high redshift mass-metallicity (MZ) relation at 10^{8}< M/M_{\sun} < 10^{10}, obtained by stacking spectra of 83 emission-line galaxies with secure redshifts between 1.3 < z < 2.3. For these…
A tight positive correlation between the stellar mass and the gas-phase metallicity of galaxies has been observed at low redshifts. The redshift evolution of this correlation can strongly constrain theories of galaxy evolution. The advent…
This review describes where we are today in light of the dust and gas properties and their relation to star formation, in low metallicity galaxies of the local universe following recent surveys from sensitive infrared space telescopes,…
New facilities and technologies have advanced our understanding of massive stars significantly over the past 30 years. Here I introduce a new large survey of massive stars using VLT-FLAMES, noting the target fields and observed binary…
Galaxies at low-redshift typically possess negative gas-phase metallicity gradients (centres more metal-rich than their outskirts). Whereas, it is not uncommon to observe positive metallicity gradients in higher-redshift galaxies ($z…
We are undertaking a program to measure emission line ratios in a selected sample of $0.5 < z < 1.0$ CFRS starforming galaxies in order to compute their Interstellar Medium metallicities. The latter are derived by means of the…
By means of chemical evolution models of different morphological types, we study the mass-metallicity (MZ) relation and its evolution with redshift. Our aim is to understand the role of galaxies of different morphological types in the MZ…
Massive stars are at the core of our observations of the Universe up to the reionization epoch, both through their intense ionizing fluxes and through the energetic end products that release fresh elements into the interstellar medium. Our…
We have investigated the mass-metallicity (M-Z) relation using galaxies at 0.4<z<1.0 from the Gemini Deep Deep Survey and Canada-France Redshift Survey. Deep K and z' band photometry allowed us to measure stellar masses for 69 galaxies.…
We present multi-wavelength imaging and near-IR spectroscopy for ten gravitationally lensed galaxies at 0.9<z<2.5 selected from a new, large sample of strong lens systems in the Sloan Digital Sky Survey (SDSS) DR7. We derive stellar masses…
The stellar metallicity is a direct measure of the amount of metals present in a galaxy, as a large part of the metals lie in its stars. In this paper we investigate new stellar metallicity indicators suitable for high-z galaxies studying…
Most massive stars are believed to be born in close binary systems where they can exchange mass, which impacts the evolution of both binary components. Their evolution is of great interest in the search for the progenitors of gravitational…
Evolution of galaxies through cosmic time has been widely studied at high redshift, but there are a few studies in this field at lower redshifts. However, low-redshifts studies will provide important clues to the evolution of galaxies,…
We present a comprehensive observational study of the gas phase metallicity of star-forming galaxies from z ~ 0 -> 3. We combine our new sample of gravitationally lensed galaxies with existing lensed and non-lensed samples to conduct a…
Our research on the age-metallicity and mass-metallicity relations of galaxies is presented and compared to the most recent investigations in the field. We have been able to measure oxygen abundances using the direct method for objects…
The chemical composition of the gas in galaxies versus cosmic time provides a very important tool for understanding galaxy evolution. Although there are many studies at high redshift, they are rather scarce at lower redshifts. However, low…
The chemical composition of high-redshift galaxies is an important property that gives clues to their past history and future evolution. Measuring abundances in distant galaxies with current techniques is often a challenge, and the…
Understanding the interstellar chemistry in low-metallicity environments is crucial to unveil physical and chemical processes in the past Galaxy or those in high-redshift galaxies, where the metallicity was significantly lower compared to…
The current classification system of M stars on the main sequence distinguishes three metallicity classes (dwarfs - dM, subdwarfs - sdM, and extreme subdwarfs - esdM). The spectroscopic definition of these classes is based on the relative…