Infrared spectroscopy of free-floating planet candidates in Upper Scorpius and Ophiuchus

Author(s): H. Bouy, M. Tamura, D. Barrado, K. Motohara, N. Castro Rodríguez, N. Miret-Roig, M. Konishi, S. Koyama, H. Takahashi, N. Huélamo, E. Bertin, J. Olivares, L. M. Sarro, A. Berihuete, J. -C. Cuillandre, P. A. B. Galli, Y. Yoshii, T. Miyata
Abstract: Context. A rich population of low-mass brown dwarfs and isolated planetary mass objects has been reported in the Upper Scorpius and Ophiuchus star-forming complex. Aims. We investigate the membership, nature, and properties of 17 of these isolated planetary mass candidates using low-resolution near-infrared spectra. Methods. We investigated the membership by looking for evidence of their youth using four diagnostics: the slope of the continuum between the J and Ks band, the Hcont, and the TLI-g gravity-sensitive indices. In addition, we compared the spectra to young and field (old) M and L-dwarf standards. Results. All the targets but one are confirmed as young ultracool objects, with spectral types between L0 and L6 and masses in the range 0.004- 0.013 M, according to evolutionary models. The status of the last target is unclear at this point. Conclusions. Only one possible contaminant has been identified among the 17 targets, suggesting that the contamination level of the original sample must be low (≤6%).
Organisation(s): Department of Astrophysics
External organisation(s): Université Bordeaux, University of Tokyo, National Astronomical Observatory of Japan, European Space Astronomy Centre (ESA), Gran Telescopio Canarias (GRANTECAN), Canada-France-Hawaii Telescope, Universidad Nacional de Educacion a Distancia (UNED), University of Cádiz, Université Paris Saclay, University of São Paulo, University of Arizona
Journal: Astronomy and Astrophysics
Volume: 664
ISSN: 0004-6361
DOI: https://doi.org/10.1051/0004-6361/202243850
Publication date: 08-2022
Peer reviewed: Yes
Austrian Fields of Science 2012: 103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas: Astronomy and Astrophysics, Space and Planetary Science
Portal url: https://ucrisportal.univie.ac.at/en/publications/14d00db2-6729-4278-bdf5-d9c6b784d41d

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