2022ApJ...938...56G


Query : 2022ApJ...938...56G

2022ApJ...938...56G - Astrophys. J., 938, 56 (2022/October-2)

A Comparative L-dwarf Sample Exploring the Interplay between Atmospheric Assumptions and Data Properties.

GONZALES E.C., BURNINGHAM B., FAHERTY J.K., LEWIS N.K., VISSCHER C. and MARLEY M.

Abstract (from CDS):

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 five L dwarfs of similar effective temperature (Teff) or spectral type to compare their pressure-temperature (P-T) profiles. Additionally, we explore the impact of an object's metallicity and the signal-to-noise ratio (S/N) of the observations on the parameters we can retrieve. We present the first atmospheric retrievals: 2MASS J15261405+2043414, 2MASS J05395200-0059019, 2MASS J15394189-0520428, and GD 165B increasing the small but growing number of L dwarfs retrieved. When compared to the atmospheric retrievals of SDSS J141624.08+134826.7, a low-metallicity d/sdL7 primary in a wide L+T binary, we find that 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 S/N is ≳80 we are in a regime where model uncertainties dominate over data measurement uncertainties. As such, S/N 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.

Abstract Copyright: © 2022. The Author(s). Published by the American Astronomical Society.

Journal keyword(s): Brown dwarfs - Exoplanets - Atmospheric composition - Fundamental parameters of stars - L dwarfs - Stellar atmospheres - Metallicity

Simbad objects: 7

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Number of rows : 7
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 SIPS J0539-0059 BD* 05 39 52.0040375405 -00 59 01.491092352           L5V 95 0
2 2MASS J14162408+1348263 BD* 14 16 24.0739698960 +13 48 26.193281184           L5 88 1
3 GD 165B BD* 14 24 39.09480 +09 17 10.4352         20.53 L4V 216 0
4 GD 165 WD* 14 24 39.1495824408 +09 17 14.160753960   14.46 14.32 14.6 14.91 DA4.1 176 0
5 2MASSI J1526140+204341 BD* 15 26 14.0097630623 +20 43 40.439684259           L5 46 0
6 2MASS J15394189-0520428 BD* 15 39 41.9238250231 -05 20 42.754120152         17.47 L4.2V 48 1
7 2MASSW J2224438-015852 BD* 22 24 43.8544128559 -01 58 53.284975671           L4.5V 150 0

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