Publications (28)
Exploring the origin of the extended main sequence turn off in M37 through the white dwarf cooling sequence
M. Griggio, M. Salaris, D. Nardiello +3
We use new observations from the Canada-France-Hawaii Telescope to study the white dwarf cooling sequence of the open cluster M37, a cluster that displays an extended main sequence…
Euclid: The convective-transition gap of 47 Tuc
M. Libralato, M. Griggio, R. Gerasimov +140
We report the first detection of the `convective-transition gap' (also known as `M-dwarf gap') in the globular cluster 47 Tuc (NGC 104) thanks to Euclid data. This feature, linked…
Photometry and astrometry with JWST -- II. NIRCam distortion correction
M. Griggio, D. Nardiello, L. R. Bedin
In preparation to make the most of our own planned James Webb Space Telescope investigations, we take advantage of publicly available calibration and early-science observations to…
JWST Imaging of the Closest Globular Clusters -- VI. The Lowest-Mass Objects in M 4 and the Galactic Bulge
L. R. Bedin, R. Gerasimov, A. Calamida +8
We present `James Webb Space Telescope' observations of M4 -- the closest globular cluster -- that probe the lower Main Sequence down to the hydrogen-burning limit. The unveiled st…
The HST Large Programme on Omega Centauri -- VII. The white dwarf cooling sequence
M. Scalco, M. Salaris, L. Bedin +9
We present a study of the white dwarf (WD) cooling sequence (CS) in the globular cluster (GC) Omega Centauri, the primary goal of a dedicated Hubble Space Telescope (HST) programme…
Astrometric star-cluster membership probability: application to the case of M 37 with Gaia EDR3
M. Griggio, L. R. Bedin
In this work, starting from the well-accepted relations in literature, we introduce a new formalism to compute the astrometric membership probabilities for sources in star clusters…
JWST Imaging of the Closest Globular Clusters -- I. Possible Infrared Excess Among White Dwarfs in NGC 6397
L. R. Bedin, D. Nardiello, M. Salaris +9
We present James Webb Space Telescope observations of the globular cluster NGC 6397 and use them to extend to infrared wavelengths the characterization of the cluster's entire whit…
Astro-photometric study of M37 with Gaia and wide-field ugi-imaging
M. Griggio, L. R. Bedin, R. Raddi +15
We present an astrometric and photometric wide-field study of the Galactic open star cluster M37 (NGC 2099). The studied field was observed with ground-based images covering a regi…
The broadening of the main sequence in the open cluster M38
M. Griggio, M. Salaris, L. R. Bedin +1
Our recent multi-band photometric study of the colour width of the lower main sequence of the open cluster M37 has revealed the presence of a sizeable initial chemical composition…
JWST Imaging of the Closest Globular Clusters -- III. Multiple Populations along the low-mass Main Sequence stars of NGC 6397
M. Scalco, M. Libralato, R. Gerasimov +9
Thanks to its exceptional near-infrared photometry, JWST can effectively contribute to the discovery, characterization, and understanding of multiple stellar populations in globula…
Signature of a chemical spread in the open cluster M37
M. Griggio, M. Salaris, S. Cassisi +2
Recent Gaia photometry of the open cluster M37 have disclosed the existence of an extended main-sequence turn off -- like in Magellanic clusters younger than about 2 Gyr -- and a m…
JWST imaging of omega Centauri: II. Evidence for a split white dwarf cooling sequence in the near-infrared
M. Scalco, M. Salaris, L. R. Bedin +11
We present a detailed analysis of the white dwarf cooling sequence (WD CS) in omega Centauri based on combined Hubble Space Telescope (HST) and JWST observations. Our analysis conf…
The VISTA Variables in the VÃa Láctea eXtended (VVVX) ESO public survey: Completion of the observations and legacy
R. K. Saito, M. Hempel, J. Alonso-GarcÃa +143
The ESO public survey VISTA Variables in the VÃa Láctea (VVV) surveyed the inner Galactic bulge and the adjacent southern Galactic disk from . Upon its conclusion, the…
High-precision astrometry with VVV -- II. A near-infrared extension of Gaia into the Galactic plane
M. Griggio, M. Libralato, A. Bellini +4
Aims. We use near-infrared, ground-based data from the VISTA Variables in the Via Lactea (VVV) survey to indirectly extend the astrometry provided by the Gaia catalog to objects in…
Photometry and astrometry with JWST -- I. NIRCam Point Spread Functions and the first JWST colour-magnitude diagrams of a globular cluster
D. Nardiello, L. R. Bedin, A. Burgasser +4
As the James Webb Space Telescope (JWST) has become fully operational, early-release data are now available to begin building the tools and calibrations for precision point-source…
JWST Imaging of the Closest Globular Clusters -- V. The White Dwarfs Cooling Sequence of M4
L. R. Bedin, M. Libralato, M. Salaris +9
We combine infrared (IR) observations collected by the James Webb Space Telescope with optical deep images by the Hubble Space Telescope taken approximately 20 years earlier to com…
Euclid: High-precision imaging astrometry and photometry from Early Release Observations. I. Internal kinematics of NGC 6397 by combining Euclid and Gaia data
M. Libralato, L. R. Bedin, M. Griggio +175
The instruments at the focus of the Euclid space observatory offer superb, diffraction-limited imaging over an unprecedented (from space) wide field of view of 0.57 deg. This e…
Euclid: Early Release Observations -- Internal kinematics and the convective-transition gap of NGC 6397
M. Griggio, M. Libralato, R. Gerasimov +130
We present a 'multiple-pass' data-reduction tool designed for Euclid, based on software developed for the Hubble Space Telescope (HST), which improves the astrometric and photometr…
JWST photometry and astrometry of 47 Tucanae. Discontinuity in the stellar sequence at the star/brown dwarf transition
M. Scalco, R. Gerasimov, L. R. Bedin +10
Using JWST Near Infrared Camera (NIRCam) images of the globular cluster 47 Tucanae (or NGC 104), taken at two epochs just 7 months apart, we derived proper-motion membership down t…
JWST imaging of the closest globular clusters -- IV. Chemistry, luminosity, and mass functions of the lowest-mass members in the NIRISS parallel fields
M. Libralato, R. Gerasimov, L. Bedin +9
We present observations of the two closest globular clusters, NGC 6121 and NGC 6397, taken with the NIRISS detector of JWST. The combination of our new JWST data with archival Hubb…
The HST large programme on NGC 6752 -- IV. The White Dwarf Sequence
L. R. Bedin, M. Salaris, J. Anderson +13
We present our final study of the white dwarf cooling sequence (WD CS) in the globular cluster NGC 6752. The investigation is the main goal of a dedicated Hubble Space Telescope la…
Photometry and astrometry with JWST -- III. A NIRCam-Gaia DR3 analysis of the open cluster NGC 2506
D. Nardiello, L. R. Bedin, M. Griggio +3
In the third paper of this series aimed at developing the tools for analysing resolved stellar populations using the cameras on board of the James Webb Space Telescope (JWST), we p…
Flux Cube Reconstruction from Slitless Spectroscopy
M. Griggio, R. E. Ryan, N. Pirzkal +19
Slitless spectroscopy enables efficient, large-area surveys without target pre-selection, yet it faces challenges from source blending, higher noise, and lost spatial-spectral info…
JWST unveils the brown dwarf sequence of 47 Tucanae
D. Nardiello, M. Griggio, L. R. Bedin
We have developed a technique to restore scientific usage in compromised (publicly-available) images collected with the James Webb Space Telescope (JWST) of the Galactic globular c…
JWST imaging of omega Centauri -- I. Luminosity and mass functions of its main sequence populations
M. Scalco, R. Gerasimov, L. R. Bedin +10
This paper presents the first study of the most massive globular cluster (GC) in the Milky Way, omega Centauri, employing recently acquired JWST deep images. By combining these dat…
The internal kinematics of NGC 2808 and its multiple populations
M. Griggio, A. Bellini, F. I. Aros +10
We use new HST observations coupled with archival data spanning a total temporal baseline of 17 years to study the internal kinematics of the multiple populations in the globular c…
Combined Gemini-South and HST photometric analysis of the globular cluster NGC 6558. The age of the metal-poor population of the Galactic Bulge
S. O. Souza, M. Libralato, D. Nardiello +8
NGC~6558 is a low-galactic latitude globular cluster projected in the direction of the Galactic bulge. Due to high reddening, this region presents challenges in deriving accurate p…
HST astrometry of the closest Brown Dwarfs -- II. Improved parameters and constraints on a third body
L. R. Bedin, J. Dietrich, A. J. Burgasser +5
Located at less than 2pc away, Luhman16AB (WISE.J104915.57-531906.1) is the closest pair of brown dwarfs and third closest `stellar' system to Earth. An exoplanet candidate in the…