Measuring young stars in space and time

• Verfasst von: Ksoll, Victor F. [VerfasserIn]
• Verfasst von: Gouliermis, Dimitrios A. [VerfasserIn]
• Verfasst von: Sabbi, Elena [VerfasserIn]
• Verfasst von: Ryon, Jenna E. [VerfasserIn]
• Verfasst von: Robberto, Massimo [VerfasserIn]
• Verfasst von: Gennaro, Mario [VerfasserIn]
• Verfasst von: Klessen, Ralf S. [VerfasserIn]
• Verfasst von: Köthe, Ullrich [VerfasserIn]
• Verfasst von: De Marchi, Guido [VerfasserIn]
• Verfasst von: Chen, C.-H. Rosie [VerfasserIn]
• Verfasst von: Cignoni, Michele [VerfasserIn]
• Verfasst von: Dolphin, Andrew E. [VerfasserIn]
• Titel: Measuring young stars in space and time
• Titelzusatz: II. the pre-main-sequence stellar content of N44
• Verf.angabe: Victor F. Ksoll, Dimitrios Gouliermis, Elena Sabbi, Jenna E. Ryon, Massimo Robberto, Mario Gennaro, Ralf S. Klessen, Ullrich Koethe, Guido de Marchi, C.-H. Rosie Chen, Michele Cignoni, and Andrew E. Dolphin
• E-Jahr: 2021
• Jahr: 2021 May 7
• Umfang: 25 S.
• Fussnoten: Gesehen am 15.06.2021
• Titel Quelle: Enthalten in: The astronomical journal
• Ort Quelle: London : Institute of Physics Publ., 1998
• Jahr Quelle: 2021
• Band/Heft Quelle: 161(2021), 6, Artikel-ID 257, Seite 1-25
• ISSN Quelle: 1538-3881
• DOI: doi:10.3847/1538-3881/abee8c
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1760469157

Abstract

The Hubble Space Telescope survey Measuring Young Stars in Space and Time (MYSST) entails some of the deepest photometric observations of extragalactic star formation, capturing even the lowest-mass stars of the active star-forming complex N44 in the Large Magellanic Cloud. We employ the new MYSST stellar catalog to identify and characterize the content of young pre-main-sequence (PMS) stars across N44 and analyze the PMS clustering structure. To distinguish PMS stars from more evolved line of sight contaminants, a non-trivial task due to several effects that alter photometry, we utilize a machine-learning classification approach. This consists of training a support vector machine (SVM) and a random forest (RF) on a carefully selected subset of the MYSST data and categorize all observed stars as PMS or non-PMS. Combining SVM and RF predictions to retrieve the most robust set of PMS sources, we find ∼26,700 candidates with a PMS probability above 95% across N44. Employing a clustering approach based on a nearest neighbor surface density estimate, we identify 16 prominent PMS structures at 1σ significance above the mean density with sub-clusters persisting up to and beyond 3σ significance. The most active star-forming center, located at the western edge of N44's bubble, is a subcluster with an effective radius of ∼5.6 pc entailing more than 1100 PMS candidates. Furthermore, we confirm that almost all identified clusters coincide with known H ii regions and are close to or harbor massive young O stars or YSOs previously discovered by MUSE and Spitzer observations.