Related papers: The solar neighbourhood age-metallicity relation -…
We analyse the evolutionary history of galaxies formed in a hierarchical scenario consistent with the concordance $\Lambda$-CDM model focusing on the study of the relation between their chemical and dynamical properties. Our simulations…
We study the impact of different galaxy statistics and empirical metallicity scaling relations on the merging rates and on the properties of compact objects binaries. First, we analyze the similarities and differences of using the star…
We study the relationship between the field star formation and cluster formation properties in a large sample of nearby dwarf galaxies. We use optical data from the Hubble Space Telescope and from ground-based telescopes to derive the ages…
We present metallicities and ages for 52 red giants in the remote Galactic dwarf spheroidal (dSph) galaxy Leo II. These stars cover the entire surface area of Leo II and are radial velocity members. We obtained medium-resolution multi-fiber…
Super-metal-rich (SMR) stars, currently in the solar neighbourhood, are expected to originate only in the inner Galaxy and have definitely migrated. We aim at studying a large sample of SMR stars to provide constraints on the epoch of the…
We have developed an homogeneous evolutionary scenario for H- and He-burning low-mass stars by computing updated stellar models for a wide metallicity and age range (0.0002$\le Z \le$0.004 and 9$\le t(Gyr) \le$15, respectively) suitable to…
We present the first results from MMT and Keck spectroscopy for a large sample of $0.1\leq z\leq1$ emission-line galaxies selected from our narrow-band imaging in the Subaru Deep Field. We measured the weak [OIII]$\lambda$4363 emission line…
We develop an approach for fitting the results of modeling of wriggling radial large scale iron pattern along the Galactic disk, derived over young (high massive) Cepheids, with the metallicity distribution, obtained using low mass long…
Star clusters are known to have smaller intrinsic metallicity spreads than dwarf galaxies due to their shorter star formation timescales. Here we use individual spectroscopic [Fe/H] measurements of stars in 19 Local Group dwarf galaxies, 13…
The Hubble Space Telescope has been used to obtain WFPC2 (V,I) photometry for a sample of 10,000 red giant stars in the outer halo of the giant elliptical NGC 5128. Comparison with the fiducial RGBs of Milky Way globular clusters and model…
In this paper we present a study of chemical abundances in six star-forming regions. Stellar parameters and metallicities are derived using high-resolution, high S/N spectra of weak-line T-Tauri stars in each region. The results show that…
The Milky Way's metal-poor stars are nearby ancient objects that are used to study early chemical evolution and the assembly and structure of the Milky Way. Here we present reliable metallicities of $\sim280,000$ stars with $-3.75 \lesssim$…
In the study of galaxy integrated light, if photometric indicators could extract age and metallicity information of high enough quality, photometry might be vastly more efficient than spectroscopy for the same astrophysical goals. Toward…
Recent observations show that the number of stars with very low metallicities in the dwarf spheroidal satellites of the Milky Way is low, despite the low average metallicities of stars in these systems. We undertake numerical simulations of…
We obtain a new determination of the metallicity distribution function (MDF) of stars within $\sim5$-$10$ kpc of the Sun, based on recently improved co-adds of $ugriz$ photometry for Stripe 82 from the Sloan Digital Sky Survey. Our new…
Stellar metallicity strongly correlates with the presence of planets and their properties. To check for new correlations between stars and the existence of an orbiting planet, we determine precise stellar parameters for a sample of…
We measure the oxygen metallicity of the ionized gas along the major axis of seven dwarf star-forming galaxies. Two of them, SDSSJ1647+21 and SDSSJ2238+14, show 0.5 dex metallicity decrements in inner regions with enhanced star-formation…
We calculate the ages, orbits and phase-space coordinates for a sample of $\sim$4 million LAMOST and Gaia stars. The ages are crossmatched and compared with values from two other popular age catalogs which derive the ages using different…
The age and chemical composition of the stars in present-day galaxies carry important clues about their star formation processes. The latest generation of population synthesis models have allowed to derive age and stellar metallicity…
The MEarth Project is a photometric survey systematically searching the smallest stars nearest to the Sun for transiting rocky planets. Since 2008, MEarth has taken approximately two million images of 1844 stars suspected to be mid-to-late…