15NH3 in the atmosphere of a cool brown dwarf
15NH3 in the atmosphere of a cool brown dwarf
Brown dwarfs serve as ideal laboratories for studying the atmospheres of giant exoplanets on wide orbits as the governing physical and chemical processes in them are nearly identical. Understanding the formation of gas giant planets is challenging, often involving the endeavour to link atmospheric abundance ratios, such as the carbon-to-oxygen (C/O) ratio, to formation scenarios. However, the complexity of planet formation requires additional tracers, as the unambiguous interpretation of the measured C/O ratio is fraught with complexity. Isotope ratios, such as deuterium-to-hydrogen and 14N/15N, offer a promising avenue to gain further insight into this formation process, mirroring their utility within the solar system. For exoplanets only a handful of constraints on 12C/13C exist, pointing to the accretion of 13C-rich ice from beyond the disks' CO iceline. Here we report on the mid-infrared detection of the 14NH3 and 15NH3 isotopologues in the atmosphere of a cool brown dwarf with an effective temperature of 380 K in a spectrum taken with the Mid-InfraRed Instrument of the James Webb Space Telescope. As expected, our results reveal a 14N/15N value consistent with star-like formation by gravitational collapse, demonstrating that this ratio can be accurately constrained. Since young stars and their planets should be more strongly enriched in the 15N isotope, we expect that 15NH3 will be detectable in a number of cold, wide-separation exoplanets.
Pascal Tremblin、Ren¨| Gastaud、Rens Waters、Ewine F. van Dishoeck、Pierre Baudoz、Michael Mueller、David Barrado、Sarah Kendrew、Paul Molli¨¨re、Pierre Royer、Polychronis Patapis、Malavika Vasist、Nicolas Crouzet、Michiel Min、Fred Lahuis、Thomas Henning、G?ran Olofsson、Daniel Rouan、Anthony Boccaletti、Silvia Scheithauer、Luis Colina、Ioannis Argyriou、Manuel Guedel、Leen Decin、Matthias Samland、Gillian Wright、Pierre-Olivier Lagage、Oliver Krause、Tom Ray、Jeroen Bouwman、Alistair Glasse、Mar¨aa Morales-Calder¨?n、Christophe Cossou、Francisco Ardevol Martinez、Adrian M. Glauser、Niall Whiteford、Inga Kamp、Olivier Absil、Ingo Waldmann、G?ran ?stlin、John Pye、Alain Coulais、Bart Vandenbussche
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Pascal Tremblin,Ren¨| Gastaud,Rens Waters,Ewine F. van Dishoeck,Pierre Baudoz,Michael Mueller,David Barrado,Sarah Kendrew,Paul Molli¨¨re,Pierre Royer,Polychronis Patapis,Malavika Vasist,Nicolas Crouzet,Michiel Min,Fred Lahuis,Thomas Henning,G?ran Olofsson,Daniel Rouan,Anthony Boccaletti,Silvia Scheithauer,Luis Colina,Ioannis Argyriou,Manuel Guedel,Leen Decin,Matthias Samland,Gillian Wright,Pierre-Olivier Lagage,Oliver Krause,Tom Ray,Jeroen Bouwman,Alistair Glasse,Mar¨aa Morales-Calder¨?n,Christophe Cossou,Francisco Ardevol Martinez,Adrian M. Glauser,Niall Whiteford,Inga Kamp,Olivier Absil,Ingo Waldmann,G?ran ?stlin,John Pye,Alain Coulais,Bart Vandenbussche.15NH3 in the atmosphere of a cool brown dwarf[EB/OL].(2023-11-14)[2025-07-01].https://arxiv.org/abs/2311.08054.点此复制
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