A5008596504- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astronomical and nuclear sciences
- Atmospheric Ozone and Climate
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Adaptive optics and wavefront sensing
- X-ray Spectroscopy and Fluorescence Analysis
- History and Developments in Astronomy
- Inertial Sensor and Navigation
- Pulsars and Gravitational Waves Research
- Calibration and Measurement Techniques
- Particle accelerators and beam dynamics
- Photocathodes and Microchannel Plates
- Nuclear physics research studies
- Pacific and Southeast Asian Studies
- Particle Accelerators and Free-Electron Lasers
- Inorganic Fluorides and Related Compounds
- Dark Matter and Cosmic Phenomena
National Institute for Astrophysics
2015-2025
Osservatorio di Astrofisica e Scienza dello Spazio
2018-2024
Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
2021-2023
Brera Astronomical Observatory
2020-2022
Aarhus University
2022
Osservatorio astronomico di Bologna
2010-2021
Instituto de Astrofísica de Canarias
2020
University of Trieste
2017
Pontificia Universidad Católica de Chile
2017
Millennium Institute of Astrophysics
2017
In this paper we adopt a chemical evolution model, which is an improved version of the Chiappini, Matteucci and Gratton (1997) assuming two main accretion episodes for formation Galaxy. The present model takes into account in more detail than previously halo density distribution explores effects threshold star process, during both disk phases. comparison between predictions available data, have focused our attention on abundance gradients as well gas, stellar rate distributions along disk....
This is the second paper of a series which aims at quantifying uncertainties in chemical evolution model predictions related to underlying assumptions. Specifically, it deals with due choice stellar yields. We adopt widely used for Galaxy and test effects changing nucleosynthesis prescriptions on predicted several species. find that, except handful elements whose stars well understood by now, large still affect predictions. especially true majority iron-peak elements, but also much more...
We discuss the evolution of oxygen, carbon and nitrogen in galaxies different morphological type by adopting detailed chemical models with star formation histories (continuous or starbursts).In all nucleosynthesis prescriptions from supernovae types low-and intermediate-mass stars are taken into account.We start computing for Milky Way stellar prescriptions.Then, a comparison between model results "key" observational constraints allows us to choose best set yields.Once yields is identified...
We have explored the Eu production in Milky Way by means of a very detailed chemical evolution model. In particular, we assumed that is formed merging neutron star (or star-black hole) binaries as well Type II supernovae. tested effects several important parameters influencing during two stars, such (i) time-scale coalescence, (ii) yields and (iii) range initial masses for progenitors stars. The from supernovae are uncertain, more than those coalescing so possibilities. compared our model...
We use state-of-the-art chemical models to track the cosmic evolution of CNO isotopes in interstellar medium (ISM) galaxies, yielding powerful constraints on their stellar initial mass function (IMF). re-assess relative roles massive stars, asymptotic giant branch (AGB) stars and novae production rare such as 13C, 15N, 17O 18O, along with 12C, 14N 16O. The isotope yields super-AGB fast-rotating are included. Having reproduced available enrichment data solar neighbourhood, across Galaxy,...
Aims. We explore the problem of site production Eu. use also information present in observed spread Eu abundances early Galaxy, not only its average trend. Moreover, we extend to other heavy elements (Ba, Sr, Rb, Zr) our investigations provide additional constraints results. Methods. adopt a stochastic chemical evolution model taking into account inhomogeneous mixing. The adopted yields from neutron star mergers (NSM) and core-collapse supernovae (SNII) are those that able explain...
Aims. Until recently, most high-resolution spectroscopic studies of the Galactic thin and thick discs were mostly confined to objects in solar vicinity. Here we aim at enlarging volume which individual chemical abundances are used characterise discs, using first internal data release Gaia-ESO survey (GES iDR1).
The spatial distribution of elemental abundances in the disc our Galaxy gives insights both on its assembly process and subsequent evolution, stellar nucleogenesis different elements. Gradients can be traced using several types objects as, for instance, (young old) stars, open clusters, HII regions, planetary nebulae. We aim at tracing radial distributions elements produced through nucleosynthetic channels -the alpha-elements O, Mg, Si, Ca Ti, iron-peak Fe, Cr, Ni Sc - by Gaia-ESO idr4...
We use Gaia-ESO Survey iDR4 data to explore the Mg-Al anti-correlation in globular clusters, that were observed as calibrators, a demonstration of quality and analysis. The results compare well with available literature, within 0.1 dex or less, after small (compared internal spreads) offset between UVES GIRAFFE 0.10-0.15 was taken into account. In particular, we present for first time NGC 5927, one most metal-rich clusters studied literature so far [Fe/H]=-0.49 dex, included connect open...
Chemical abundances and abundance ratios measured in galaxies provide precious information about the mechanisms, modes time scales of assembly cosmic structures. Yet, nucleogenesis chemical evolution elements heavier than helium are dictated mostly by physics stars shape stellar mass spectrum. In particular, estimates CNO isotopic hot, dusty media high-redshift starburst offer a unique glimpse into initial function (IMF) extreme environments that can not be accessed with direct observations...
Relics of ancient accretion events experienced by the Milky Way are predominantly located within stellar halo our Galaxy. However, debris from different objects display overlapping distributions in dynamical spaces, making it extremely challenging to properly disentangle their contribution build-up To shed light on this chaotic context, we initiated a program aimed at homogeneous chemical tagging local Way, focusing component retrograde motion, since is expected host large fraction stars...
Stellar lifetimes and initial mass function are basic ingredients of chemical evolution models, for which different recipes can be found in the literature. In this paper, we quantify effects on studies uncertainties these two parameters. We concentrate models Milky Way, because large number good observational constraints. Such have already ruled out significant temporal variations stellar our own Galaxy, with exception perhaps very early phases its evolution. Therefore, here assume a...
We present early high-resolution spectroscopic observations of the nova V1369 Cen. have detected an absorption feature at 6695.6 Å that we identified as blueshifted 7Li i λ6708 Å. The line, moving −550 km s−1, was observed in five spectra obtained different epochs. Based on intensity this infer a single outburst can inject Galaxy = 0.3–4.8 × 10−10 . Given current estimates Galactic rate, amount is sufficient to explain puzzling origin overabundance lithium young star populations.
Stellar evolution models predict that internal mixing should cause some sodium overabundance at the surface of red giants more massive than ~ 1.5--2.0 Msun. The aluminium abundance not be affected. Nevertheless, observational results disagree about presence and/or degree Na and Al overabundances. In addition, Galactic chemical adopting different stellar yields lead to quite predictions for behavior [Na/Fe] [Al/Fe] versus [Fe/H]. Overall, observed trends these abundances with metallicity are...
Context. Stars evolving through the asymptotic giant branch (AGB) phase provide significant feedback to their host system, which is both gas enriched in nuclear-burning products, and dust formed winds, they eject into interstellar medium. Therefore, AGB stars are an essential ingredient for chemical evolution of Milky Way other galaxies. Aims. We study models with super-solar metallicities complete our vast database, so far extending from metal-poor solar-chemical compositions. yields masses...
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...
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...
Globular clusters (GCs) are considerably more complex structures than previously thought, harboring at least two stellar generations that present clearly distinct chemical abundances. Scenarios explaining the abundance patterns in GCs mostly assume originally had to be much massive today, and second generation of stars originates from gas shed by first (FG). The lack metallicity spread most further requires supernova-enriched ejected FG is completely lost within ∼30 Myr, a hypothesis never...
Context. The inner disc, linking the thin disc with bulge, has been somehow neglected in past because of intrinsic difficulties its study, due, e.g., to crowding and high extinction. Open clusters located are among best tracers chemistry at different ages distances. Aims. We analyse chemical patterns four open within 7 kpc Galactic Centre field stars infer properties Gaia-ESO survey idr2/3 data release. Methods. derive parameters newly observed cluster, Berkeley 81, finding an age about 1...
Context. Open clusters are key tools to study the spatialdistribution of abundances in disk and their evolution with time.
We present Iron, Magnesium, Calcium, and Titanium abundances for 235 stars in the central region of Sagittarius dwarf spheroidal galaxy (within 9.0 arcmin ~70 pc from center) medium-resolution Keck/DEIMOS spectra. All considered belong to massive globular cluster M54 or nucleus (Sgr,N). In particular we provide 109 with [Fe/H] > -1.0, more than doubling available sample spectroscopic metallicity alpha-elements abundance estimates Sgr dSph this regime. Also, find first confirmed member...
Aim of this work is to determine C, N, and O abundances in stars Galactic open clusters the Gaia-ESO survey compare observed with those predicted by current stellar evolution models. In pilot paper, we investigate first three intermediate-age clusters. High-resolution spectra, FLAMES-UVES spectrograph on ESO VLT telescope, were analysed using a differential model atmosphere method. Abundances carbon derived C2 band heads at 5135 5635.5 {\AA}. The wavelength interval 6470- 6490 {\AA}, CN...
Abstract In this work, we study the Galactic evolution of lithium by means chemical models in light most recent spectroscopic data from stellar surveys. We consider detailed for Milky Way halo, discs, and bulge, compare our model predictions with these different components. particular, focus on decrease at high metallicity observed AMBRE Project, Gaia-ESO Survey, other surveys, which still remains unexplained theoretical models. analyse various producers confirm that novae are main source...