A5023757864- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- History and Developments in Astronomy
- Astronomical Observations and Instrumentation
- Astronomical and nuclear sciences
- Advanced optical system design
- Geomagnetism and Paleomagnetism Studies
- Spectroscopy and Laser Applications
- Pigment Synthesis and Properties
- Optical measurement and interference techniques
- Advanced Measurement and Metrology Techniques
- Adaptive optics and wavefront sensing
- X-ray Spectroscopy and Fluorescence Analysis
Osservatorio Astronomico di Padova
2019-2025
National Institute for Astrophysics
2024-2025
University of Padua
2021-2023
The 'chromosome map' diagram (ChM) proved a successful tool to identify and characterize multiple populations (MPs) in 59 Galactic Globular Clusters (GCs). Here, we construct ChMs for 11 GCs of both Magellanic Clouds (MCs) with different ages compare MPs extra-Galactic environments, explore whether this phenomenon is universal through 'place' 'time'. are detected five clusters. fractions 1G stars, ranging from about 50% more than 80%, significantly higher those observed similar present-day...
In the past years, we have undertaken an extensive investigation of LMC and SMC star clusters based on HST data. We present photometry astrometry stars in 101 fields observed with WFC/ACS, UVIS/WFC3 NIR/WFC3 cameras. These comprise 113 clusters. provide differential-reddening maps illustrate various scientific outcomes that arise from early inspection photometric catalogs. particular, new insights extended main-sequence turn-off (eMSTO) phenomenon: i) detected eMSTOs two clusters, KMHK361...
Binary stars play a crucial role in our understanding of the formation and evolution star clusters their stellar populations. We use Gaia Data Release 3 to homogeneously analyze 78 Galactic open unresolved binary systems they host, each composed two main sequence (MS) stars. first investigated structural parameters these clusters, such as core radius central density, determined cluster mass function (MF) total by interpolating density profile cluster. measured fraction binaries with large...
Abstract The pseudo two-color diagram, known as chromosome map (ChM), is a valuable tool for identifying globular clusters (GCs), which consist of single or multiple stellar populations (MPs). Recent surveys Galactic GCs using ChMs have provided stringent observational constraints on the formation and their populations. However, these primarily focused at moderate distances from center composed MPs. In this paper, we present first detailed study composition four in outer halo Milky Way: Arp...
ABSTRACT We present a detailed analysis of the internal dynamics multiple stellar populations (MPs) in 28 Galactic globular clusters (GCs) across wide field view, extending from innermost regions to clusters’ outskirts. Using astrophotometric catalogues ground-based observations, Gaia and Hubble Space Telescope (HST), we identify first- (1P) second-population (2P) stars, study MPs using high-precision DR3 HST proper motions. Our results reveal that while 1P transitions isotropy slight...
Disentangling distinct stellar populations along the red-giant branches (RGBs) of Globular Clusters (GCs) is possible by using pseudo two-color diagram dubbed chromosome map (ChM). One most intriguing findings that so-called first-generation (1G) stars, characterized same chemical composition their natal cloud, exhibit extended sequences in ChM. Unresolved binaries and internal variations helium or metallicity have been suggested to explain this phenomenon. Here, we derive high-precision...
We use images collected with the near-infrared camera (NIRCam) on board James Webb Space Telescope and Hubble (HST) to investigate multiple populations at bottom of main sequence (MS) 47 Tucanae. The F115W vs. F115W-F322W2 CMD from NIRCam shows that, below knee, MS stars span a wide color range, where majority M-dwarfs exhibit blue colors, tail are distributed toward red. A similar pattern is observed F160W F110W-F160W HST, also visible in optical F606W F606W-F814W CMD. narrow faint masses...
Abstract James Webb Space Telescope (JWST) observations have been demonstrated to be efficient in detecting multiple stellar populations globular clusters (GCs) the low-mass regime of M dwarfs. We present an overview, and first results, different projects that can explored by using JWST gathered under program GO2560 for 47 Tucanae, entirely devoted investigation very-low-mass stars, which includes spectroscopic data faintest GC stars spectra are available. Our color–magnitude diagram (CMD)...
ABSTRACT The location of Galactic globular clusters’ (GC) stars on the horizontal branch (HB) should mainly depend GC metallicity, ‘first parameter’, but it is actually result complex interactions between red giant (RGB) mass-loss, coexistence multiple stellar populations with different helium content, and presence a ‘second parameter’ that produces dramatic differences in HB morphology GCs similar metallicity ages (like pair M3–M13). In this work, we combine entire data set from Hubble...
ABSTRACT The presence of differential reddening in the direction Galactic globular clusters (GCs) has proven to be a serious limitation traditional colour–magnitude diagram (CMD) analysis. Here, we estimate local variations 56 GCs. To do that, use public catalogues derived as part Hubble Space Telescope UV Legacy Survey GCs, which include photometry F275W, F336W, F438W, F606W, and F814W filters. We corrected for found that 21 out GCs adopted correction procedure significantly improved CMDs....
Recent work on metal-intermediate globular clusters (GCs) with [Fe/H]=$-1.5$ and $-0.75$ has illustrated the theoretical behavior of multiple populations in photometric diagrams obtained James Webb Space Telescope (JWST). These results are confirmed by observations among M-dwarfs 47 Tucanae. Here, we explore metal-poor GCs [Fe/H]=$-$2.3. We take advantage synthetic spectra isochrones that account for chemical composition to identify separate distinct stellar GCs. derived high-precision...
We investigate the behavior of multiple stellar populations in globular clusters (GCs) using photometric diagrams constructed with Euclid photometry. By employing synthetic spectra and isochrones that incorporate chemical differences between first-population (1P) stars, resembling field second-population (2P) enriched helium nitrogen but depleted carbon oxygen, we identify, from a theoretical perspective, color-magnitude chromosome maps most effective at distinguishing these within GCs....
Abstract Wide-field photometry of Galactic globular clusters (GCs) has been investigated to overcome limitations from the small field view Hubble Space Telescope in study multiple populations. In particular, “chromosome maps” (ChMs) built with ground-based were constructed identify first- and second-generation (1G 2G) stars over wide view. The ChMs allow us derive fraction distinct populations an analyzed We present here radial distribution 2G 29 GCs. distributions show that all GCs have...
We investigate the behavior of multiple stellar populations in globular clusters (GCs) using photometric diagrams constructed with Euclid photometry. By employing synthetic spectra and isochrones that incorporate chemical differences between first-population (1P) stars (resembling field stars) second-population (2P) (enriched helium nitrogen, but depleted carbon oxygen) we have identified, from a theoretical perspective, color-magnitude chromosome maps most effective at distinguishing these...
Hubble Space Telescope (HST) photometry is providing an extensive analysis of globular clusters (GCs). In particular, the pseudo two-colour diagram dubbed 'chromosome map (ChM)' allowed to detect and characterize their multiple populations with unprecedented detail. The main limitation these studies small field view HST, which makes it challenging investigate some important aspects populations, such as spatial distributions internal kinematics in outermost cluster regions. To overcome this...
Abstract Recent work has revealed two classes of globular clusters (GCs), dubbed Type I and II. II GCs are characterized by both a blue red giant branch composed stars with different metallicities, often coupled distinct abundances in the slow neutron-capture elements (s-elements). Here we continue chemical tagging adding least massive this class, NGC 1261 6934. Based on spectroscopy photometry, find to be slightly enhanced [Fe/H] ∼0.1 dex confirm that 6934 iron ∼0.2 dex. Neither nor show...
Recent work has shown that NIR Hubble Space Telescope (HST) photometry allows us to disentangle multiple populations (MPs) among M dwarfs of globular clusters (GCs) and investigate this phenomenon in very low-mass (VLM) stars. Here, we present the color-magnitude diagrams (CMDs) nine GCs open cluster NGC 6791 F110W F160W bands HST, showing main sequences (MSs) below knee are either broadened or split thus providing evidence MPs VLM In contrast, MS is consistent with a single population. The...
Abstract The “chromosome maps” (ChMs) of globular clusters (GCs) have revealed that these ancient structures are inhomogeneous in metallicity various ways and different natures. Type II GCs generally display larger variations, sometimes coupled with slow neutron-capture ( s ) element enrichments on the ChMs redder sequences, which been interpreted as due to multiple generations stars. On other hand, most first populations (1P) form large ranges Δ F275W,F814W values, pointing toward a not...
Abstract Understanding the formation of multiple populations in globular clusters (GCs) represents a challenge for stellar population studies. Nevertheless, outermost cluster regions, likely to hold clues about initial configuration GC stars, remain underexplored. We use synthetic spectra reflecting chemical compositions first- and second-population (1P, 2P) stars 47 Tucanae identify spectral regions sensitive these populations. This led us define new photometric bands that effectively...
The origin of multiple stellar populations in Globular Clusters (GCs) is one the greatest mysteries modern astrophysics. N-body simulations suggest that present-day dynamics GC stars can constrain events occurred at high redshift and led to formation populations. Here, we combine multi-band photometry from Hubble Space Telescope (HST) ground-based facilities with HST Gaia Data Release 2 proper motions investigate spatial distributions plane sky type II GCs NGC 5139 ($\omega\,$Centauri) 6656...
The origin of young star clusters represents a major challenge for modern stellar astrophysics. While rotation partially explains the colour spread observed along main-sequence turn-offs, i.e. where stars leave after exhaustion hydrogen in their core, and multiple main sequences colour-magnitude diagrams systems younger than approximately 2 Gyr, it appears that an age difference may still be required to fulfill observational constraints. Here we introduce alternative approach exploits...
The amount of mass lost by stars during the red-giant branch (RGB) phase is one main parameters to understand and correctly model late stages stellar evolution. Nevertheless, a fully-comprehensive knowledge RGB loss still missing. Galactic Globular Clusters (GCs) are ideal targets derive empirical formulations loss, but presence multiple populations with different chemical compositions has been major challenge constrain masses losses. Recent work disentangled distinct along horizontal (HB)...
Young and intermediate-age star clusters of both Magellanic Clouds exhibit complex color-magnitude diagrams. In addition to the extended main-sequence turn-offs (eMSTOs), commonly observed in younger than ~2 Gyr, ~800 Myr split main sequences (MSs). These comprise a blue MS, composed stars with low-rotation rates, red which hosts fast-rotating stars. While it is widely accepted that stellar populations different rotation rates are responsible for eMSTOs MSs, their formation evolution still...
Aims. Ancient galactic globular clusters (GCs) have long fascinated astronomers due to their intriguing multiple stellar populations (MPs), which are characterized by variations in light element abundances. Among these clusters, type II GCs stand out as they exhibit stars with large differences heavy-element chemical These enigmatic comprising approximately 17% of analyzed MPs, been hypothesized be the remnants accreted dwarf galaxies. Methods. We focus on one most debated GCs, namely, NGC...
The pseudo two-color diagram, known as chromosome map (ChM), is a valuable tool for identifying globular clusters (GCs) that consist of single or multiple stellar populations (MPs). Recent surveys Galactic GCs using the ChM have provided stringent observational constraints on formation and their populations. However, these primarily focused at moderate distances from center composed MPs. In this paper, we present first detailed study composition four in outer halo Milky Way: Arp 2, Ruprecht...