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Your search keyword '"Giuseppe Germanò"' showing total 3 results
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3 results on '"Giuseppe Germanò"'

1. Inferring stellar parameters and their uncertainties from high-resolution spectroscopy using invertible neural networks

Author

Candebat, Nils, Sacco, Giuseppe Germano, Magrini, Laura, Belfiore, Francesco, Van-der-Swaelmen, Mathieu, and Zibetti, Stefano

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

Context: New spectroscopic surveys will increase the number of astronomical objects requiring characterization by over tenfold.. Machine learning tools are required to address this data deluge in a fast and accurate fashion. Most machine learning algorithms can not estimate error directly, making them unsuitable for reliable science. Aims: We aim to train a supervised deep-learning algorithm tailored for high-resolution observational stellar spectra. This algorithm accurately infer precise estimates while providing coherent estimates of uncertainties by leveraging information from both the neural network and the spectra. Methods: We train a conditional Invertible Neural Network (cINN) on observational spectroscopic data obtained from the GIRAFFE spectrograph (HR10 and HR21 setups) within the Gaia-ESO survey. A key features of cINN is its ability to produce the Bayesian posterior distribution of parameters for each spectrum. By analyzing this distribution, we inferred parameters and their uncertainties. Several tests have been applied to study how parameters and errors are estimated. Results: We achieved an accuracy of 28K in $T_{\text{eff}}$, 0.06 dex in $\log g$, 0.03 dex in $[\text{Fe/H}]$, and between 0.05 dex and 0.17 dex for the other abundances for high quality spectra. Accuracy remains stable with low signal-to-noise ratio spectra. The uncertainties obtained are well within the same order of magnitude. The network accurately reproduces astrophysical relationships both on the scale of the Milky Way and within smaller star clusters. We created a table containing the new parameters generated by our cINN. Conclusion: This neural network represents a compelling proposition for future astronomical surveys. These coherent derived uncertainties make it possible to reuse these estimates in other works as Bayesian priors and thus present a solid basis for future work., Comment: Accepted for publication in A&A

Published
2024
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2. The role of radial migration in open cluster and field star populations with Gaia dr3

Author

Vázquez, Carlos Viscasillas, Magrini, Laura, Spina, Lorenzo, Tautvaišienė, Gražina, Van der Swaelmen, Mathieu, Randich, Sofia, and Sacco, Giuseppe Germano

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract

The survival time of a star cluster depends on its total mass, density, and thus size, as well as on the environment in which it was born and in which lies. Its dynamical evolution is influenced by various factors such as gravitational effects of the Galactic bar, spiral structures, and molecular clouds. Overall, the factors that determine the longevity of a cluster are complex and not fully understood. This study aims to investigate if open clusters and field stars respond differently to the perturbations that cause radial migration. In particular, we aim at understanding the nature of the oldest surviving clusters. We compared the time evolution of the kinematic properties of two Gaia DR3 samples: the first sample is composed of $\sim$40 open clusters and the second one of $\sim$66,000 MSTO field stars. Both selected samples are composed of stars selected with the same quality criterion, belonging to the thin disc, in a similar metallicity range, located in the same Galactocentric region [7.5-9 kpc] and with ages >1 Gyr. We performed a statistical analysis comparing the properties of the samples of field stars and of open clusters. A qualitative comparison of kinematic and orbital properties reveals that clusters younger than 2-3 Gyr are more resistant to perturbations than field stars and they move along quasi-circular orbits. Conversely, clusters older than approximately 3 Gyr have more eccentric and inclined orbits than isolated stars in the same age range. Such orbits lead them to reach higher elevations on the Galactic plane, maximising their probability to survive several Gyr longer. A formal statistical analysis reveals that there are differences among the time evolution of most of the kinematic and orbital properties of field stars and open clusters. Our results suggest that oldest survived clusters are usually more massive and move on orbits with higher eccentricity., Comment: 13 pages, 20 figures, 2 tables. Article accepted for publication in A&A

Published
2023

3. Ariel: Enabling planetary science across light-years

Author

Tinetti, Giovanna, Eccleston, Paul, Haswell, Carole, Lagage, Pierre-Olivier, Leconte, Jérémy, Lüftinger, Theresa, Micela, Giusi, Min, Michel, Pilbratt, Göran, Puig, Ludovic, Swain, Mark, Testi, Leonardo, Turrini, Diego, Vandenbussche, Bart, Osorio, Maria Rosa Zapatero, Aret, Anna, Beaulieu, Jean-Philippe, Buchhave, Lars, Ferus, Martin, Griffin, Matt, Guedel, Manuel, Hartogh, Paul, Machado, Pedro, Malaguti, Giuseppe, Pallé, Enric, Rataj, Mirek, Ray, Tom, Ribas, Ignasi, Szabó, Robert, Tan, Jonathan, Werner, Stephanie, Ratti, Francesco, Scharmberg, Carsten, Salvignol, Jean-Christophe, Boudin, Nathalie, Halain, Jean-Philippe, Haag, Martin, Crouzet, Pierre-Elie, Kohley, Ralf, Symonds, Kate, Renk, Florian, Caldwell, Andrew, Abreu, Manuel, Alonso, Gustavo, Amiaux, Jerome, Berthé, Michel, Bishop, Georgia, Bowles, Neil, Carmona, Manuel, Coffey, Deirdre, Colomé, Josep, Crook, Martin, Désjonqueres, Lucile, Díaz, José J., Drummond, Rachel, Focardi, Mauro, Gómez, Jose M., Holmes, Warren, Krijger, Matthijs, Kovacs, Zsolt, Hunt, Tom, Machado, Richardo, Morgante, Gianluca, Ollivier, Marc, Ottensamer, Roland, Pace, Emanuele, Pagano, Teresa, Pascale, Enzo, Pearson, Chris, Pedersen, Søren Møller, Pniel, Moshe, Roose, Stéphane, Savini, Giorgio, Stamper, Richard, Szirovicza, Peter, Szoke, Janos, Tosh, Ian, Vilardell, Francesc, Barstow, Joanna, Borsato, Luca, Casewell, Sarah, Changeat, Quentin, Charnay, Benjamin, Civiš, Svatopluk, Foresto, Vincent Coudé du, Coustenis, Athena, Cowan, Nicolas, Danielski, Camilla, Demangeon, Olivier, Drossart, Pierre, Edwards, Billy N., Gilli, Gabriella, Encrenaz, Therese, Kiss, Csaba, Kokori, Anastasia, Ikoma, Masahiro, Morales, Juan Carlos, Mendonça, João, Moneti, Andrea, Mugnai, Lorenzo, Muñoz, Antonio García, Helled, Ravit, Kama, Mihkel, Miguel, Yamila, Nikolaou, Nikos, Pagano, Isabella, Panic, Olja, Rengel, Miriam, Rickman, Hans, Rocchetto, Marco, Sarkar, Subhajit, Selsis, Franck, Tennyson, Jonathan, Tsiaras, Angelos, Venot, Olivia, Vida, Krisztián, Waldmann, Ingo P., Yurchenko, Sergey, Szabó, Gyula, Zellem, Rob, Al-Refaie, Ahmed, Alvarez, Javier Perez, Anisman, Lara, Arhancet, Axel, Ateca, Jaume, Baeyens, Robin, Barnes, John R., Bell, Taylor, Benatti, Serena, Biazzo, Katia, Błęcka, Maria, Bonomo, Aldo Stefano, Bosch, José, Bossini, Diego, Bourgalais, Jeremy, Brienza, Daniele, Brucalassi, Anna, Bruno, Giovanni, Caines, Hamish, Calcutt, Simon, Campante, Tiago, Canestrari, Rodolfo, Cann, Nick, Casali, Giada, Casas, Albert, Cassone, Giuseppe, Cara, Christophe, Carone, Ludmila, Carrasco, Nathalie, Chioetto, Paolo, Cortecchia, Fausto, Czupalla, Markus, Chubb, Katy L., Ciaravella, Angela, Claret, Antonio, Claudi, Riccardo, Codella, Claudio, Comas, Maya Garcia, Cracchiolo, Gianluca, Cubillos, Patricio, Da Peppo, Vania, Decin, Leen, Dejabrun, Clemence, Delgado-Mena, Elisa, Di Giorgio, Anna, Diolaiti, Emiliano, Dorn, Caroline, Doublier, Vanessa, Doumayrou, Eric, Dransfield, Georgina, Dumaye, Luc, Dunford, Emma, Escobar, Antonio Jimenez, Van Eylen, Vincent, Farina, Maria, Fedele, Davide, Fernández, Alejandro, Fleury, Benjamin, Fonte, Sergio, Fontignie, Jean, Fossati, Luca, Funke, Bernd, Galy, Camille, Garai, Zoltán, García, Andrés, García-Rigo, Alberto, Garufi, Antonio, Sacco, Giuseppe Germano, Giacobbe, Paolo, Gómez, Alejandro, Gonzalez, Arturo, Gonzalez-Galindo, Francisco, Grassi, Davide, Griffith, Caitlin, Guarcello, Mario Giuseppe, Goujon, Audrey, Gressier, Amélie, Grzegorczyk, Aleksandra, Guillot, Tristan, Guilluy, Gloria, Hargrave, Peter, Hellin, Marie-Laure, Herrero, Enrique, Hills, Matt, Horeau, Benoit, Ito, Yuichi, Jessen, Niels Christian, Kabath, Petr, Kálmán, Szilárd, Kawashima, Yui, Kimura, Tadahiro, Knížek, Antonín, Kreidberg, Laura, Kruid, Ronald, Kruijssen, Diederik J. M., Kubelík, Petr, Lara, Luisa, Lebonnois, Sebastien, Lee, David, Lefevre, Maxence, Lichtenberg, Tim, Locci, Daniele, Lombini, Matteo, Lopez, Alejandro Sanchez, Lorenzani, Andrea, MacDonald, Ryan, Magrini, Laura, Maldonado, Jesus, Marcq, Emmanuel, Migliorini, Alessandra, Modirrousta-Galian, Darius, Molaverdikhani, Karan, Molinari, Sergio, Mollière, Paul, Moreau, Vincent, Morello, Giuseppe, Morinaud, Gilles, Morvan, Mario, Moses, Julianne I., Mouzali, Salima, Nakhjiri, Nariman, Naponiello, Luca, Narita, Norio, Nascimbeni, Valerio, Nikolaou, Athanasia, Noce, Vladimiro, Oliva, Fabrizio, Palladino, Pietro, Papageorgiou, Andreas, Parmentier, Vivien, Peres, Giovanni, Pérez, Javier, Perez-Hoyos, Santiago, Perger, Manuel, Pestellini, Cesare Cecchi, Petralia, Antonino, Philippon, Anne, Piccialli, Arianna, Pignatari, Marco, Piotto, Giampaolo, Podio, Linda, Polenta, Gianluca, Preti, Giampaolo, Pribulla, Theodor, Puertas, Manuel Lopez, Rainer, Monica, Reess, Jean-Michel, Rimmer, Paul, Robert, Séverine, Rosich, Albert, Rossi, Loic, Rust, Duncan, Saleh, Ayman, Sanna, Nicoletta, Schisano, Eugenio, Schreiber, Laura, Schwartz, Victor, Scippa, Antonio, Seli, Bálint, Shibata, Sho, Simpson, Caroline, Shorttle, Oliver, Skaf, N., Skup, Konrad, Sobiecki, Mateusz, Sousa, Sergio, Sozzetti, Alessandro, Šponer, Judit, Steiger, Lukas, Tanga, Paolo, Tackley, Paul, Taylor, Jake, Tecza, Matthias, Terenzi, Luca, Tremblin, Pascal, Tozzi, Andrea, Triaud, Amaury, Trompet, Loïc, Tsai, Shang-Min, Tsantaki, Maria, Valencia, Diana, Vandaele, Ann Carine, Van der Swaelmen, Mathieu, Vardan, Adibekyan, Vasisht, Gautam, Vazan, Allona, Del Vecchio, Ciro, Waltham, Dave, Wawer, Piotr, Widemann, Thomas, Wolkenberg, Paulina, Yip, Gordon Hou, Yung, Yuk, Zilinskas, Mantas, Zingales, Tiziano, and Zuppella, Paola

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution., Comment: Ariel Definition Study Report, 147 pages. Reviewed by ESA Science Advisory Structure in November 2020. Original document available at: https://www.cosmos.esa.int/documents/1783156/3267291/Ariel_RedBook_Nov2020.pdf/

Published
2021

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