A5084766731- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
- History and Developments in Astronomy
- Nuclear Physics and Applications
- Computational Physics and Python Applications
- Scientific Research and Discoveries
- Calibration and Measurement Techniques
- Phase Equilibria and Thermodynamics
- Adaptive optics and wavefront sensing
- Nuclear physics research studies
- Geological and Geophysical Studies
- Galaxies: Formation, Evolution, Phenomena
- Historical Astronomy and Related Studies
- Astronomical and nuclear sciences
- History of Science and Medicine
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- High-pressure geophysics and materials
- Reservoir Engineering and Simulation Methods
Vilnius University
2018-2024
Arcetri Astrophysical Observatory
2022
Goddard Space Flight Center
2020
University of Puerto Rico at Humacao
2014
In the last 15 years different ground-based spectroscopic surveys have been started (and completed) with general aim of delivering stellar parameters and elemental abundances for large samples Galactic stars, complementing Gaia astrometry. Among those surveys, Gaia-ESO Public Spectroscopic Survey (GES), only one performed on a 8m class telescope, was designed to target 100,000 stars using FLAMES ESO VLT (both Giraffe UVES spectrographs), covering all Milky Way populations, special focus open...
Context. The Gaia-ESO Public Spectroscopic Survey is an ambitious project designed to obtain astrophysical parameters and elemental abundances for 100 000 stars, including large representative samples of the stellar populations in Galaxy, a well-defined sample 60 (plus 20 archive) open clusters. We provide internally consistent results calibrated on benchmark stars star clusters, extending across very wide range ages. This provides legacy data set intrinsic value, equally wide-ranging...
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...
The last decade has seen a revolution in our knowledge of the Galaxy thanks to Gaia and asteroseismic space missions ground-based spectroscopic surveys. To complete this picture, it is necessary map ages its stellar populations. During recent years, dependence on time abundance ratios involving slow (s) neutron-capture $\alpha$ elements (called chemical-clocks) been used provide estimates ages, usually limited volume close Sun. We aim analyse relations chemical clocks Galactic disc extending...
We aim to constrain the mixing processes in low-mass stars by investigating behaviour of Li surface abundance after main sequence. take advantage data from sixth internal release Gaia-ESO, idr6, and Gaia Early Data Release 3, edr3. select a sample sequence, sub-giant, giant which is measured Gaia-ESO survey, belonging 57 open clusters with ages 120~Myr about 7 Gyr Milky Way fields, covering range [Fe/H] between -1.0 +0.5dex. study abundances as function stellar parameters. compare observed...
Chemical clocks based on s-process element/α element ratios are widely used to estimate the ages of Galactic stellar populations. However, s/α versus age relations not universal, varying with metallicity, location in disc, and specific elements. Moreover, current chemical evolution models struggle reproduce observed increase at young ages, particularly for Ba. Our aim is provide different regions Milky Way (MW) disc order identify conditions required s/H s/Fe relations. We adopted a detailed...
The aim of this work is to determine abundances neutron-capture elements for thin- and thick-disc F, G, K stars in several sky fields near the north ecliptic pole compare results with Galactic chemical evolution models, explore elemental gradients according stellar ages, mean galactocentric distances, maximum heights above plane. observational data were obtained 1.65m telescope at Moletai Astronomical Observatory a fibre-fed high-resolution spectrograph. Elemental determined using...
The use of abundance ratios involving Y, or other slow-neutron capture elements, are routinely used to infer stellar ages.Aims.We aim explain the observed [Y/H] and [Y/Mg] star clusters located in inner disc with a new prescription for mixing Asymptotic Giant Branch (AGB) stars. In Galactic chemical evolution model, we adopt set AGB yields which magnetic is included. We compare results model sample abundances ages open at different Galactocentric distances. causes less efficient production Y...
We study the abundance patterns and radial gradients of s-process elements (Y, Zr, Ba, La Ce), r-process (Eu) mixed-process (Mo, Nd Pr) in Galactic thin disc by means a detailed two-infall chemical evolution model for Milky Way with state-of-the-art nucleosynthesis prescriptions. consider from merging neutron stars (MNS), magneto-rotational supernovae (MR-SNe) synthesis low- intermediate- mass (LIMS) rotating massive stars. The predictions our are compared data sixth release Gaia-ESO survey,...
It has recently been suggested that all giant stars with mass below 2 $M_{\odot}$ suffer an episode of surface lithium enrichment between the tip red branch (RGB) and clump (RC). We test if above result can be confirmed in a sample RC RGB are members open clusters. discuss Li abundances six clusters ages 1.5 4.9 Gyr (turn-off masses 1.1 1.7 $M_{\odot}$). These observations compared predictions different models include rotation-induced mixing, thermohaline instability, mixing induced by first...
Context. The survival time of a star cluster depends on its total mass, density, and thus size, as well the environment in which it was born lies. Its dynamical evolution is influenced by various factors such gravitational effects Galactic bar, spiral structures, molecular clouds. Overall, that determine longevity are complex not fully understood. Aims. This study aims to investigate whether open clusters field stars respond differently perturbations cause radial migration. In particular, we...
Abstract In fulfilling the aims of planetary and asteroseismic research missions, such as that NASA Transiting Exoplanet Survey Satellite (TESS) space telescope, accurate stellar atmospheric parameters a detailed chemical composition are required inputs. We have observed high-resolution spectra for all 848 bright ( V < 8 mag) stars cooler than F5 spectral class in area up to 12 deg surrounding northern TESS continuous viewing zone uniformly determined main parameters, ages, orbital...
A renewed interest about the origin of \emph{r}-process elements has been stimulated by multi-messenger observation gravitational event GW170817, with detection both waves and electromagnetic corresponding to merger two neutron stars. Such phenomenon proposed as one main sources \emph{r}-process. However, at different metallicities is still under debate. We aim investigating in Galactic thin disc population. From sixth internal data release \emph{Gaia}-ESO we have collected a large sample...
Recent evidence from spectroscopic surveys points towards the presence of a metal-poor, young stellar population in low-alpha , chemically thin disk. In this context, investigation spatial distribution and time evolution precise, unbiased abundances is fundamental to disentangle scenarios formation Galaxy. We study abundance gradients Milky Way by taking advantage large sample open star clusters, which are among best tracers for purpose. particular, we used data last release Gaia -ESO...
Context. Recent evidences from spectroscopic surveys point towards the presence of a metal-poor, young stellar population in chemical thin disk. In this context, investigation spatial distribution and time evolution precise, unbiased abundances is fundamental to disentangle scenarios Galaxy. Aims. We study abundance gradients Milky Way by taking advantage large sample open clusters, which are among best tracers for purpose. particular, we use data last release Gaia-ESO survey. Methods....
Accurate atmospheric parameters and chemical composition of stars play a vital role in characterizing physical exoplanetary systems understanding their formation. A full asteroseismic characterization star is also possible if its main are known. The NASA Transiting Exoplanet Survey Satellite (TESS) space telescope will very important searching exoplanets around bright stellar variability research. We have observed all 302 (V < 8 mag) cooler than F5 spectral class the northern TESS continuous...
We present completed observations of the NGC 7448 galaxy group and background volume as part blind neutral hydrogen Arecibo Galaxy Environment Survey. Our cover a region spanning 5°× 4°, over redshift range approximately −2000 <cz < 20 000 km s−1. A total 334 objects are detected, mostly in three overdensities at cz ∼ 7500, 9600 11 400 The density is extremely high (15 deg−2) many (∼24 per cent) show signs extended H i emission, including some features much 800 kpc projected length. describe...
BurstCube aims to expand sky coverage in order detect, localize, and rapidly disseminate information about gamma-ray bursts (GRBs). is a '6U' CubeSat with an instrument comprised of 4 Cesium Iodide (CsI) scintillators coupled arrays Silicon photo-multipliers (SiPMs) will be sensitive gamma-rays between 50 keV 1 MeV. assist current observatories, such as Swift Fermi, the detection GRBs well provide astronomical context gravitational wave (GW) events detected by LIGO, Virgo, KAGRA. currently...
A renewed interest about the origin of \emph{r}-process elements has been stimulated by multi-messenger observation gravitational event GW170817, with detection both waves and electromagnetic corresponding to merger two neutron stars. Such phenomenon proposed as one main sources \emph{r}-process. However, at different metallicities is still under debate. We aim investigating in Galactic thin disc population. From sixth internal data release \emph{Gaia}-ESO we have collected a large sample...
(abridged) The third data release of Gaia, has provided stellar parameters, metallicity [M/H], [{\alpha}/Fe], individual abundances, broadening parameter from its RVS spectra for about 5.6 million objects thanks to the GSP-Spec module. catalogue publishes radial velocity 33 sources. We took advantage intersections between Gaia and Gaia-ESO compare their abundances rotational velocities. aimed at verifying overall agreement two datasets, considering various calibrations quality-control flag...
Context. The third data release of Gaia, has provided stellar parameters, metallicity [M/H], [ α /Fe], individual abundances, broadening parameter from its Radial Velocity Spectrograph (RVS) spectra for about 5.6 million objects thanks to the GSP-Spec module, implemented in Gaia pipeline. catalogue also publishes radial velocity 33 sources. In recent years, many spectroscopic surveys with ground-based telescopes have been undertaken, including public survey -ESO, designed be complementary...
Context. Star clusters, composed of stars born from the same molecular cloud, serve as invaluable natural laboratories for understanding fundamental processes governing stellar formation and evolution. Aims. This study aims to investigate correlations between Mean Interdistance ($ \bar{D_{\mathrm{i}}} $), Closest \bar{D_{\mathrm{c}}} $) Median Weighted Central \bar{D_{\mathrm{cc}}} with age star examining their evolutionary trends assessing robustness these quantities possible indicators....
Context: Star clusters, composed of stars born from the same molecular cloud, serve as invaluable natural laboratories for understanding fundamental processes governing stellar formation and evolution. Aims: This study aims to investigate correlations between Mean Interdistance ($\bar{D_{i}}$), Closest ($\bar{D_{c}}$) Median Weighted Central ($\bar{D_{cc}}$) with age star examining their evolutionary trends assessing robustness these quantities possible indicators. Methods: We selected a...
Context. Hot subdwarf stars are compact blue evolved objects, burning helium in their cores surrounded by a tiny hydrogen envelope. In the Hertzsprung-Russell Diagram they located end of Horizontal Branch. Most models agree on quite probable common envelope binary evolution scenario Red Giant phase. However, current binarity rate for these objects is yet unsolved, but key, question this field. Aims. This study aims to develop novel classification method identifying hot binaries within large...