A Comparative L-dwarf Sample Exploring the Interplay Between Atmospheric Assumptions and Data Properties
arXiv:2209.02754 · doi:10.3847/1538-4357/ac8f2a
Abstract
Comparisons of atmospheric retrievals can reveal powerful insights on the strengths and limitations of our data and modeling tools. In this paper, we examine a sample of 5 similar effective temperature (Teff) or spectral type L dwarfs to compare their pressure-temperature (P-T) profiles. Additionally, we explore the impact of an object's metallicity and the observations' signal-to-noise (SNR) on the parameters we can retrieve. We present the first atmospheric retrievals: 2MASS J152614052043414, 2MASS J053952000059019, 2MASS J153941890520428, and GD 165B increasing the small but growing number of L-dwarfs retrieved. When compared to atmospheric retrievals of SDSS J141624.08+134826.7, a low-metallicity d/sdL7 primary in a wide L+T binary, we find similar Teff sources have similar P-T profiles with metallicity differences impacting the relative offset between their P-T profiles in the photosphere. We also find that for near-infrared spectra, when the SNR is we are in a regime where model uncertainties dominate over data measurement uncertainties. As such, SNR does not play a role in the retrieval's ability to distinguish between a cloud-free and cloudless model, but may impact the confidence of the retrieved parameters. Lastly, we also discuss how to break cloud model degeneracies and the impact of extraneous gases in a retrieval model.
19 pages, 3 figures, 7 tables
References in corpus (20)
- Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
- The Evolution of L and T Dwarfs in Color-Magnitude Diagrams
- Young L Dwarfs Identified in the Field: A Preliminary Low-Gravity, Optical Spectral Sequence from L0 to L5
- A Sample of Very Young Field L Dwarfs and Implications for the Brown Dwarf "Lithium Test" at Early Ages
- Spitzer/IRAC Photometry of M, L, and T Dwarfs
- Uniform Atmospheric Retrieval Analysis of Ultracool Dwarfs I: Characterizing Benchmarks, Gl570D and HD3651B
- High temperature condensate clouds in super-hot Jupiter atmospheres
- SpeX Spectroscopy of Unresolved Very Low Mass Binaries. II. Identification of Fourteen Candidate Binaries with Late-M/Early-L and T Dwarf Components
- Helios-r2 -- A new Bayesian, open-source retrieval model for brown dwarfs and exoplanet atmospheres
- The NIRSPEC Brown Dwarf Spectroscopic Survey II: High-Resolution J-Band Spectra of M, L and T Dwarfs
- Primeval very low-mass stars and brown dwarfs. I. Six new L subdwarfs, classification and atmospheric properties
- A Uniform Retrieval Analysis of Ultracool Dwarfs. III. Properties of Y-Dwarfs
- An Infrared High Proper Motion Survey Using 2MASS and SDSS: Discovery of M, L and T Dwarfs
- On the Radii of Brown Dwarfs Measured with AKARI Near-Infrared Spectroscopy
- Parallax and Luminosity Measurements of an L Subdwarf
- Trigonometric Parallaxes for Two Late-Type Subdwarfs: LSR1425+71 (sdM8.0) and the Binary LSR1610-00 (sd?M6pec)
- Retrieval Study of Brown Dwarfs Across the L-T Sequence
- Considerations for Atmospheric Retrieval of High-Precision Brown Dwarf Spectra
- A Reanalysis of the Fundamental Parameters and Age of TRAPPIST-1
- Correlated spectral variability in brown dwarfs