Related papers: Large-scale time-series spectroscopy for stellar a…
The last decade has seen a revolution in our knowledge of the Galaxy thanks to the Gaia and asteroseismic space missions and the ground-based spectroscopic surveys. To complete this picture, it is necessary to map the ages of its stellar…
A key to understand exoplanets is characterisation of their host stars. One of the most powerful tools to characterise stellar properties like effective temperature, surface gravity and metallicity, is spectroscopy based on observations of…
Understanding the origin and long-term evolution of the Solar System is a fundamental goal of planetary science and astrophysics. This chapter describes our current understanding of the key processes that shaped our planetary system,…
The star formation, mass assembly and chemical enrichment histories of galaxies, and their present distributions of dark matter, remain encoded in their stellar populations. Distinguishing the actual distribution functions of stellar age,…
Combined spectroscopic abundance analyses of stable and radioactive elements can be applied for deriving stellar ages. The achievable precision depends on factors related to spectroscopy, nucleosynthesis, and chemical evolution. We quantify…
I discuss how spectroscopy of extragalactic globular clusters provides a powerful probe of the formation history and mass distribution of galaxies. One critical area is spectroscopy of objects which have been identified as candidate young…
Determining the sequence of events in the formation of stars and planetary systems and their time-scales is essential for understanding those processes, yet establishing ages is fundamentally difficult because we lack direct indicators. In…
Long-period variables are bright, evolved red giant stars showing periodic photometric changes due to stellar pulsation. They follow one or more period-luminosity and period-age relations, which make them highly promising distance…
In this contribution I will discuss fundamental stellar parameters as determined from young star clusters; specifically those with ages less than or approximately equal to that of the Pleiades. I will focus primarily on the use of stellar…
The details of bulge formation via collapse, mergers, secular processes or their interplay remain unresolved. To start answering this question and quantify the importance of distinct mechanisms, we mapped a sample of three galactic bulges…
The Next Generation Space Telescope (NGST) will gather unprecedented spectro-photometric data on galaxies out to the highest redshifts. It is therefore crucial to identify the spectro-photometric diagnostics within reach of NGST, which will…
We report on our observing program to obtain integrated spectrophotometry, intermediate and high resolution major axis spectra, and U,B,R surface photo- metry of a representative sample of ~200 galaxies in the nearby field. The main goal of…
The Large Early Galaxy Census (LEGA-C) is a Public Spectroscopic Survey of $\sim3200$ $K$-band selected galaxies at redshifts $z=0.6-1.0$ with stellar masses M_star > 1e10M_sun, conducted with VIMOS on ESO's Very Large Telescope. The survey…
Dwarf galaxies are generally faint. To derive their age and metallicity distributions, it is critical to optimize the use of any collected photon. Koleva et al., using full spectrum fitting, have found strong population gradients in some…
Stars and planets can be seen as the second fundamental building blocks of baryons in the universe (only second to the dust and gas in molecular clouds). Their formation involves dust grain growth of many orders of magnitude and a myriad of…
We present a unified framework to derive fundamental stellar parameters by combining all available observational and theoretical information for a star. The algorithm relies on the method of Bayesian inference, which for the first time…
Here we report some results from an ESO-VLT programme to observe individual stars in nearby dwarf galaxies at high resolution with the UVES spectrograph (Tolstoy, Venn, Shetrone, Primas, Hill, Kaufer & Szeifert 2002, submitted to AJ). We…
Deriving precise stellar ages is a challenging task. Consequently, age-dependent relations - such as the age-metallicity and age-velocity dispersion relations of the Milky Way, or the age-rotation-activity relation of low-mass stars - are…
Strong gravitational lensing at the galaxy scale is a valuable tool for various applications in astrophysics and cosmology. The primary uses of galaxy-scale lensing are to study elliptical galaxies' mass structure and evolution, constrain…
In this article we summarise on-going work on the so-called Gaia FGK Benchmark Stars. This work consists of the determination of their atmospheric parameters and of the construction of a high-resolution spectral library. The definition of…