A5023514630- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Phase Equilibria and Thermodynamics
- Geomagnetism and Paleomagnetism Studies
- Astronomical Observations and Instrumentation
- Astronomical and nuclear sciences
- Atomic and Molecular Physics
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Sesquiterpenes and Asteraceae Studies
- Space Science and Extraterrestrial Life
- Neutrino Physics Research
- Earth Systems and Cosmic Evolution
- Ionosphere and magnetosphere dynamics
- Advanced Chemical Physics Studies
- Scientific Research and Discoveries
- Plasma Diagnostics and Applications
- Spectroscopy and Laser Applications
- Statistical and numerical algorithms
Trieste Astronomical Observatory
2009-2024
Observatoire de la Côte d’Azur
2022-2024
Centre National de la Recherche Scientifique
2022-2024
Université Côte d'Azur
2022-2023
Aarhus University
2018-2023
National Institute for Astrophysics
2016-2023
Konkoly Observatory
2022
Research Centre for Astronomy and Earth Sciences
2022
Hungarian Research Network
2022
University of Trieste
2008-2017
Precise stellar ages from asteroseismology have become available and can help setting stronger constraints on the evolution of Galactic disc components. Recently, has confirmed a clear age difference in solar annulus between two distinct sequences [$\alpha$/Fe] versus [Fe/H] abundance ratios relation: high-$\alpha$ low-$\alpha$ populations. We aim at reproducing these new data with chemical models including different assumptions for history number accretion events. tested approaches: revised...
The chemo-physical parametrisation of stellar spectra is essential for understanding the nature and evolution stars Galactic populations. Gaia DR3 contains RVS data performed by General Stellar Parametriser-spectroscopy, module. Here we describe first 34 months observations. GSP-spec estimates parameters from combined single stars. main analysis workflow described here, MatisseGauguin, based on projection optimisation methods provides atmospheric parameters; individual chemical abundances N,...
We present the first chemical evolution model for Enceladus, alias Gaia Sausage, to investigate star formation history of one most massive satellites accreted by Milky Way during a major merger event. Our best Enceladus nicely fits observed stellar [$\alpha$/Fe]-[Fe/H] abundance trends, and reproduces metallicity distribution function, assuming low efficiency, fast infall time scale, mild outflow intensity. predict median age stars $12.33^{+0.92}_{-1.36}$ Gyr, - at with our Galaxy...
We study the chemical evolution of thick and thin discs Galaxy by comparing detailed models with recent data from Archéologie avec Matisse Basée sur les aRchives de l'ESO project. The suggest that stars in form two distinct sequences disc showing higher [α/Fe] ratios. adopt different approaches to model discs. In particular, we (i) a two-infall approach where forms fast before means gas accretion episode, whereas second episode on longer time-scale; (ii) parallel approach, but at rates. By...
Abstract Chemical characterization of the Galactic center is essential for understanding its formation and structural evolution. Trends alpha ( α ) elements, such as magnesium, silicon, calcium, serve powerful diagnostic tools, offering insights into star rates gas-infall history. However, high extinction has previously hindered studies. In this study, we present a detailed chemical abundance analysis M giants in Milky Way's nuclear cluster (NSC), focusing on -element trends with...
Our aim is to show how different hypotheses about Type Ia supernova progenitors can affect Galactic chemical evolution. We include SN progenitor models, identified by their distribution of time delays, in a very detailed evolution model for the Milky Way which follows several species. test single degenerate and double models progenitors, as well other more empirical based on differences delay distributions. find that assuming or scenario produces negligible predicted [O/Fe] vs. [Fe/H]...
Abridged: We used the fourth internal data release of Gaia-ESO survey to characterize bulge chemistry, spatial distribution, kinematics, and compare it chemically with thin thick disks. The sample consist on ~2500 red clump stars in 11 fields ($-10^\circ\leq l\leq+8^\circ$ $-10^\circ\leq b\leq-4^\circ$), a set ~6300 disk selected for comparison. MDF is confirmed be bimodal across whole sampled area, metal-poor dominating at high latitudes. metal-rich exhibit bar-like kinematics display...
With the wealth of information from large surveys and observational campaigns in contemporary era, it is critical to properly exploit data constrain parameters Galactic chemical evolution models quantify associated uncertainties. We aim at constraining two-infall for solar annulus using measured abundance ratios seismically inferred age stars APOKASC sample. In revised by Spitoni et al. (2019), a significant delay $\sim 4.3$ Gyr has been invoked between two episodes gas accretion. this work,...
The spatial distribution of elemental abundances and their time evolution are among the major constraints to disentangle scenarios formation Galaxy. We used sample open clusters available in final release Gaia-ESO survey trace Galactic radial abundance iron ratio gradients, evolution. selected member stars 62 clusters, with ages from 0.1 about 7~Gyr, located thin disc at Galactocentric radii 6 21~kpc. analysed shape resulting [Fe/H] gradient, average gradients [El/H] [El/Fe] combining...
Gaia DR3 provides radial velocities for 33 million stars and spectroscopically derived atmospheric parameters more than five targets. When combined with the astrometric data, these allow us to derive orbital stellar that are key in order understand populations of Milky Way perform galactic archaeology. We use calibrated parameters, 2MASS Gaia-EDR3 photometry, parallax-based distances compute, via an isochrone fitting method, ages, initial masses reddenings spectroscopic parameters. also...
Context. The recent Gaia Data Release 3 (DR3) represents an unparalleled revolution in Galactic archaeology, providing numerous radial velocities and chemical abundances for millions of stars as well all-sky coverage. Aims We present a new evolution model the disc components (high- low- α sequence stars) designed to reproduce abundance ratios provided by General Stellar Parametriser-spectroscopy module DR3 constrained detailed star formation (SF) histories both thick thin inferred from...
The majority of chemical evolution models assume that the Galactic disk forms by means infall gas and divide into several independent rings without exchange matter between them. However, if is important, radial flows should be taken account as a dynamical consequence infall. aim this paper to test effect on detailed (one-infall two-infall) for Milky Way with different prescriptions law star formation rate. We found, inflow constant speed metallicity gradient tends steepen. Taking time scale...
We compute the abundance gradients along disc of Milky Way by means two-infall model: in particular, oxygen and iron their temporal evolution. First, we explore effects several physical processes which influence formation evolution gradients. They are (i) inside-out disc, (ii) a threshold gas density for star formation, (iii) variable efficiency (iv) radial flows speed (v) different total surface mass (gas plus stars) distributions halo. able to reproduce at best present day if assume an no...
In this paper, we study the formation and chemical evolution of Milky Way disc with particular focus on abundance patterns ([$\alpha$/Fe] vs. [Fe/H]) at different Galactocentric distances, present-time gradients along time gradients. We consider models for Galactic developed by Grisoni et al. (2017) solar neighborhood, both two-infall one-infall ones, extend our analysis to other distances. particular, examine processes which mainly influence gradients: inside-out scenario, a variable star...
The Galactic habitable zone is defined as the region with highly enough metallicity to form planetary systems in which Earth-like planets could be born and might capable of sustaining life surviving destructive effects nearby supernova explosion events. chemical evolution models can useful tools for studying galactic zones different systems. Our aim here find using Milky Way disc, adopting most recent prescriptions dust probability finding around M FGK stars. Moreover, first time, we will...
Context. Analytical models of chemical evolution, including inflow and outflow gas, are important tools for studying how the metal content in galaxies evolves as a function time.
Since the onset of `space revolution' high-precision high-cadence photometry, asteroseismology has been demonstrated as a powerful tool for informing Galactic archaeology investigations. The launch NASA TESS mission enabled seismic-based inferences to go full sky -- providing clear advantage large ensemble studies different Milky Way components. Here we demonstrate its potential investigating Galaxy by carrying out first asteroseismic study red giant stars observed TESS. We use sample 25...
Galactic disc chemical evolution models generally ignore azimuthal surface density variation that can introduce abundance gradients. Recent observations, however, have revealed changes with azimuth in the gas and stellar components of both Milky Way external galaxies. To quantify effects spiral arm fluctuations on variations oxygen iron abundances We develop a new 2D galactic model, capable following not just radial but also inhomogeneities. The resulting from Way-like N-body formation...
ABSTRACT We study the evolution of Milky Way thick and thin discs in light most recent observational data. In particular, we analyse abundance gradients O, N, Fe, Mg along disc as well [Mg/Fe] versus [Fe/H] relations metallicity distribution functions at different Galactocentric distances. run several models starting from two-infall paradigm, assuming that formed by means two infall episodes, explore physical parameters, such radial gas flows, variable efficiency star formation, times for...
Analysis of several spectroscopic surveys indicates the presence a bimodality between disc stars in abundance ratio space alpha /Fe versus Fe/H . The two stellar groups are commonly referred to as high-alpha and low-alpha sequences. Some models capable reproducing such invoke hiatus star formation history our Galaxy, whereas other explain sequences by means migration. Our aim is show that existence gap rate evident APOGEE DR17, if one plots Fe/alpha /H confirming previous suggestions. We...
In this work, we study the formation and chemical evolution of Galactic bulge with particular focus on abundance pattern ([Mg/Fe] vs. [Fe/H]), metallicity age distribution functions. We consider detailed models for inner disc, aim shedding light connection between these components origin stars. particular, first present a model assuming fast intense star formation, majority stars forming timescale less than 1 Gyr. Then analyze possibility two distinct stellar populations in bulge, as...
Abstract We present a detailed study of the composition 20 M giants in Galactic center with 15 them confirmed to be nuclear star cluster. As control sample we have also observed 7 Milky Way disk similar stellar parameters. All 27 stars are using NIRSPEC spectrograph on KECK II telescope K -band at resolving power R = 23,000. report first silicon abundance trends versus [Fe/H] for center. While finding disk/bulge-like trend subsolar metallicities, find that [Si/Fe] is enhanced supersolar...
The trends of chemical abundances and abundance ratios observed in stars different ages, kinematics, metallicities bear the imprints several physical processes that concur to shape host galaxy properties. By inspecting these trends, we get precious information on stellar nucleosynthesis, mass spectrum, timescale structure formation, efficiency star as well any inward or outward flows gas. In this paper, analyse recent determinations carbon-to-iron carbon-to-oxygen environments (the Milky Way...
Taking advantage of the recent Gaia Data Release 3 (DR3), we map chemical inhomogeneities in Milky Way's disc out to a distance $\sim$ 4 kpc from Sun, using different samples bright giant stars. The are selected effective temperatures and surface gravities GSP-Spec module, expected trace stellar populations typical age. cool (old) giants exhibit relatively smooth radial metallicity gradient with an azimuthal dependence. Binning Galactic azimuth $\phi$, slope gradually varies $d$[M/H]$/dR...
Context. The so-called action variables are specific functions of the positions and velocities that remain constant along stellar orbit. astrometry provided by Gaia Early Data Release 3 (EDR3), combined with inferred from Radial Velocity Spectrograph (RVS) spectra DR3, allows for estimation these actions largest volume stars to date. Aims. We explore such aim locating structures in Galactic disc. Methods. computed orbital parameters DR3 stars, assuming an axisymmetric model Milky Way. Using...