In order to obtain a complete census of the stellar and substellar population, down to a few in the similar to 1 Myr old Orion Nebula Cluster, we used the infrared channel of the Wide Field Camera 3 of the Hubble Space Telescope with the F139M and F130N filters. These bandpasses correspond to the 1.4 mu m H2O absorption feature and an adjacent line-free continuum region. Out of 4504 detected sources, 3352 (about 75%) appear fainter thanm(130) = 14 (Vega mag) in the F130N filter, a brightness corresponding to the hydrogen-burning limit mass () at similar to 1 Myr. Of these, however, only 742 sources have a negative F130M-F139N color index, indicative of the presence of H2O vapor in absorption, and can therefore be classified as bona fide M and L dwarfs, with effective temperaturesT less than or similar to 2850 K at an assumed 1 Myr cluster age. On our color-magnitude diagram (CMD), this population of sources with H2O absorption appears clearly distinct from the larger background population of highly reddened stars and galaxies with positive F130M-F139N color index and can be traced down to the sensitivity limit of our survey,m(130) 21.5, corresponding to a 1 Myr old 3planetary-mass object under about 2 mag of visual extinction. Theoretical models of the BT-Settl family predicting substellar isochrones of 1, 2, and 3 Myr down to similar to 1M less than or similar to 20. We perform a Bayesian analysis to determine extinction, mass, and effective temperature of each substellar member of our sample, together with its membership probability.

HST Survey of the Orion Nebula Cluster in the H 2 O 1.4 μ m Absorption Band. I. A Census of Substellar and Planetary-mass Objects / Massimo Robberto; Mario Gennaro; Maria Giulia Ubeira Gabellini; Lynne A. Hillenbrand; Camilla Pacifici; Leonardo Ubeda; Morten Andersen; Travis Barman; Andrea Bellini; Nicola Da Rio; Selma E. de Mink; Giuseppe Lodato; Carlo Felice Manara; Imants Platais; Laurent Pueyo; Giovanni Maria Strampelli; Jonathan C. Tan; L. Testi. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - STAMPA. - 896:1(2020), pp. 79.1-79.20. [10.3847/1538-4357/ab911e]

HST Survey of the Orion Nebula Cluster in the H 2 O 1.4 μ m Absorption Band. I. A Census of Substellar and Planetary-mass Objects

L. Testi
2020

Abstract

In order to obtain a complete census of the stellar and substellar population, down to a few in the similar to 1 Myr old Orion Nebula Cluster, we used the infrared channel of the Wide Field Camera 3 of the Hubble Space Telescope with the F139M and F130N filters. These bandpasses correspond to the 1.4 mu m H2O absorption feature and an adjacent line-free continuum region. Out of 4504 detected sources, 3352 (about 75%) appear fainter thanm(130) = 14 (Vega mag) in the F130N filter, a brightness corresponding to the hydrogen-burning limit mass () at similar to 1 Myr. Of these, however, only 742 sources have a negative F130M-F139N color index, indicative of the presence of H2O vapor in absorption, and can therefore be classified as bona fide M and L dwarfs, with effective temperaturesT less than or similar to 2850 K at an assumed 1 Myr cluster age. On our color-magnitude diagram (CMD), this population of sources with H2O absorption appears clearly distinct from the larger background population of highly reddened stars and galaxies with positive F130M-F139N color index and can be traced down to the sensitivity limit of our survey,m(130) 21.5, corresponding to a 1 Myr old 3planetary-mass object under about 2 mag of visual extinction. Theoretical models of the BT-Settl family predicting substellar isochrones of 1, 2, and 3 Myr down to similar to 1M less than or similar to 20. We perform a Bayesian analysis to determine extinction, mass, and effective temperature of each substellar member of our sample, together with its membership probability.
2020
HST Survey of the Orion Nebula Cluster in the H 2 O 1.4 μ m Absorption Band. I. A Census of Substellar and Planetary-mass Objects / Massimo Robberto; Mario Gennaro; Maria Giulia Ubeira Gabellini; Lynne A. Hillenbrand; Camilla Pacifici; Leonardo Ubeda; Morten Andersen; Travis Barman; Andrea Bellini; Nicola Da Rio; Selma E. de Mink; Giuseppe Lodato; Carlo Felice Manara; Imants Platais; Laurent Pueyo; Giovanni Maria Strampelli; Jonathan C. Tan; L. Testi. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - STAMPA. - 896:1(2020), pp. 79.1-79.20. [10.3847/1538-4357/ab911e]
Massimo Robberto; Mario Gennaro; Maria Giulia Ubeira Gabellini; Lynne A. Hillenbrand; Camilla Pacifici; Leonardo Ubeda; Morten Andersen; Travis Barman; Andrea Bellini; Nicola Da Rio; Selma E. de Mink; Giuseppe Lodato; Carlo Felice Manara; Imants Platais; Laurent Pueyo; Giovanni Maria Strampelli; Jonathan C. Tan; L. Testi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/940965
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