Medium-resolution 0.97–5.3 μm Spectra of Very Young Benchmark Brown Dwarfs with NIRSpec on Board the James Webb Space Telescope
Spectra of young benchmark brown dwarfs with well-known ages are vital to characterize other brown dwarfs, for which ages are in general not known. These spectra are also crucial to test atmospheric models, which have the potential to provide detailed information about the atmospheres of these objec...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astronomical Journal |
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| Online Access: | https://doi.org/10.3847/1538-3881/ad2938 |
| _version_ | 1797229479643316224 |
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| author | Elena Manjavacas Pascal Tremblin Stephan Birkmann Jeff Valenti Catarina Alves de Oliveira Tracy L. Beck G. Giardino N. Lützgendorf B. J. Rauscher M. Sirianni |
| author_facet | Elena Manjavacas Pascal Tremblin Stephan Birkmann Jeff Valenti Catarina Alves de Oliveira Tracy L. Beck G. Giardino N. Lützgendorf B. J. Rauscher M. Sirianni |
| author_sort | Elena Manjavacas |
| collection | DOAJ |
| description | Spectra of young benchmark brown dwarfs with well-known ages are vital to characterize other brown dwarfs, for which ages are in general not known. These spectra are also crucial to test atmospheric models, which have the potential to provide detailed information about the atmospheres of these objects. However, to test atmospheric models optimally, medium-resolution, long-wavelength-coverage spectra with well-understood uncertainties are ideal, such as the spectra provided by the NIRSpec instrument on board the James Webb Space Telescope. In this paper, we present medium-resolution JWST/NIRSpec spectra of two young brown dwarfs, TWA 28 (M9.0) and TWA 27A (M9.0), and one planetary-mass object, TWA 27B (L6.0), members of the TW Hydrae Association (age ∼ 10 Myr). We show the richness of the atomic lines and molecular bands present in the spectra. All objects show signs of a circumstellar disk, via a near-infrared excess and/or via emission lines. We matched a set of cloudless atmospheric spectra ( ATMO ), and cloudy atmospheric spectra ( BT-Settl ) to our NIRSpec spectra, and analyzed which wavelength ranges and spectral features both models reproduce best. Both models derive consistent parameters for the three sources, and predict the existence of CH _4 at 3.35 μ m in TWA 27B. Nonetheless, in contrast to other slightly older objects with similar spectral type, like PSO 318.5–22 and VHS 1256b, this feature is not present in the spectrum of TWA 27B. The lack of the CH _4 feature might suggest that the L–T transition of very young dwarfs starts at later spectral types than for older brown dwarfs. |
| first_indexed | 2024-04-24T15:13:15Z |
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| id | doaj.art-e210b66415494a4c8e67e2cd97558312 |
| institution | Directory Open Access Journal |
| issn | 1538-3881 |
| language | English |
| last_indexed | 2024-04-24T15:13:15Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astronomical Journal |
| spelling | doaj.art-e210b66415494a4c8e67e2cd975583122024-04-02T10:11:35ZengIOP PublishingThe Astronomical Journal1538-38812024-01-01167416810.3847/1538-3881/ad2938Medium-resolution 0.97–5.3 μm Spectra of Very Young Benchmark Brown Dwarfs with NIRSpec on Board the James Webb Space TelescopeElena Manjavacas0https://orcid.org/0000-0003-0192-6887Pascal Tremblin1https://orcid.org/0000-0001-6172-3403Stephan Birkmann2Jeff Valenti3Catarina Alves de Oliveira4https://orcid.org/0000-0003-2896-4138Tracy L. Beck5https://orcid.org/0000-0002-6881-0574G. Giardino6https://orcid.org/0000-0002-9262-7155N. Lützgendorf7https://orcid.org/0000-0002-4034-0080B. J. Rauscher8https://orcid.org/0000-0003-2662-6821M. Sirianni9AURA for the European Space Agency (ESA) , ESA Office, Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 USA emanjavacas@stsci.edu; Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USAUniversité Paris-Saclay , UVSQ, CNRS, CEA, Maison de la Simulation, F-91191 Gif-sur-Yvette, FranceEuropean Space Agency , European Space Astronomy Centre, Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, SpainSpace Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USAEuropean Space Agency , European Space Astronomy Centre, Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, SpainSpace Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USAATG Europe for the European Space Agency , ESTEC, Keplerlaan 1, 2200 AG Noordwijk, The NetherlandsEuropean Space Agency , ESTEC, Keplerlaan 1, 2200 AG Noordwijk, The NetherlandsNASA Goddard Space Flight Center , Observational Cosmology Laboratory, Greenbelt, USAEuropean Space Agency (ESA) , ESA Office, Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USASpectra of young benchmark brown dwarfs with well-known ages are vital to characterize other brown dwarfs, for which ages are in general not known. These spectra are also crucial to test atmospheric models, which have the potential to provide detailed information about the atmospheres of these objects. However, to test atmospheric models optimally, medium-resolution, long-wavelength-coverage spectra with well-understood uncertainties are ideal, such as the spectra provided by the NIRSpec instrument on board the James Webb Space Telescope. In this paper, we present medium-resolution JWST/NIRSpec spectra of two young brown dwarfs, TWA 28 (M9.0) and TWA 27A (M9.0), and one planetary-mass object, TWA 27B (L6.0), members of the TW Hydrae Association (age ∼ 10 Myr). We show the richness of the atomic lines and molecular bands present in the spectra. All objects show signs of a circumstellar disk, via a near-infrared excess and/or via emission lines. We matched a set of cloudless atmospheric spectra ( ATMO ), and cloudy atmospheric spectra ( BT-Settl ) to our NIRSpec spectra, and analyzed which wavelength ranges and spectral features both models reproduce best. Both models derive consistent parameters for the three sources, and predict the existence of CH _4 at 3.35 μ m in TWA 27B. Nonetheless, in contrast to other slightly older objects with similar spectral type, like PSO 318.5–22 and VHS 1256b, this feature is not present in the spectrum of TWA 27B. The lack of the CH _4 feature might suggest that the L–T transition of very young dwarfs starts at later spectral types than for older brown dwarfs.https://doi.org/10.3847/1538-3881/ad2938L dwarfsM dwarf starsSpectroscopy |
| spellingShingle | Elena Manjavacas Pascal Tremblin Stephan Birkmann Jeff Valenti Catarina Alves de Oliveira Tracy L. Beck G. Giardino N. Lützgendorf B. J. Rauscher M. Sirianni Medium-resolution 0.97–5.3 μm Spectra of Very Young Benchmark Brown Dwarfs with NIRSpec on Board the James Webb Space Telescope The Astronomical Journal L dwarfs M dwarf stars Spectroscopy |
| title | Medium-resolution 0.97–5.3 μm Spectra of Very Young Benchmark Brown Dwarfs with NIRSpec on Board the James Webb Space Telescope |
| title_full | Medium-resolution 0.97–5.3 μm Spectra of Very Young Benchmark Brown Dwarfs with NIRSpec on Board the James Webb Space Telescope |
| title_fullStr | Medium-resolution 0.97–5.3 μm Spectra of Very Young Benchmark Brown Dwarfs with NIRSpec on Board the James Webb Space Telescope |
| title_full_unstemmed | Medium-resolution 0.97–5.3 μm Spectra of Very Young Benchmark Brown Dwarfs with NIRSpec on Board the James Webb Space Telescope |
| title_short | Medium-resolution 0.97–5.3 μm Spectra of Very Young Benchmark Brown Dwarfs with NIRSpec on Board the James Webb Space Telescope |
| title_sort | medium resolution 0 97 5 3 μm spectra of very young benchmark brown dwarfs with nirspec on board the james webb space telescope |
| topic | L dwarfs M dwarf stars Spectroscopy |
| url | https://doi.org/10.3847/1538-3881/ad2938 |
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