TY - JOUR
T1 - Patchy Forsterite Clouds in the Atmospheres of Two Highly Variable Exoplanet Analogs
AU - Vos, Johanna M.
AU - Burningham, Ben
AU - Faherty, Jacqueline K.
AU - Alejandro, Sherelyn
AU - Gonzales, Eileen
AU - Calamari, Emily
AU - Gagliuffi, Daniella Bardalez
AU - Visscher, Channon
AU - Tan, Xianyu
AU - Morley, Caroline V.
AU - Marley, Mark
AU - Gemma, Marina E.
AU - Whiteford, Niall
AU - Gaarn, Josefine
AU - Park, Grace
N1 - Funding Information:
We thank the anonymous referee for useful comments, which improved the quality of this work. The data used in this publication were collected through the MENDEL high-performance computing (HPC) cluster at the American Museum of Natural History. This HPC cluster was developed with National Science Foundation (NSF) Campus Cyberinfrastructure support through Award #1925590. This work has made use of the University of Hertfordshire’s high-performance computing facility. This work was supported by NSF Award 1909776, NASA XRP Award #80NSSC22K0142, and HST-GO-15924.001-A. E.G. acknowledges support from the Heising-Simons Foundation for this research. C.V.M. acknowledges support from NSF Astronomy and Astrophysics Research Grants grant No. 1910969. This work benefited from the 2022 Exoplanet Summer Program in the Other Worlds Laboratory (OWL) at the University of California, Santa Cruz, a program funded by the Heising-Simons Foundation.
Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/2/1
Y1 - 2023/2/1
N2 - We present an atmospheric retrieval analysis of a pair of highly variable, ∼200 Myr old, early T type planetary-mass exoplanet analogs SIMP J01365662+0933473 and 2MASS J21392676+0220226 using the Brewster retrieval framework. Our analysis, which makes use of archival 1-15 μm spectra, finds almost identical atmospheres for both objects. For both targets, we find that the data is best described by a patchy, high-altitude forsterite (Mg2SiO4) cloud above a deeper, optically thick iron (Fe) cloud. Our model constrains the cloud properties well, including the cloud locations and cloud particle sizes. We find that the patchy forsterite slab cloud inferred from our retrieval may be responsible for the spectral behavior of the observed variability. Our retrieved cloud structure is consistent with the atmospheric structure previously inferred from spectroscopic variability measurements, but clarifies this picture significantly. We find consistent C/O ratios for both objects, which supports their formation within the same molecular cloud in the Carina-Near moving group. Finally, we note some differences in the constrained abundances of H2O and CO, which may be caused by data quality and/or astrophysical processes such as auroral activity and their differing rotation rates. The results presented in this work provide a promising preview of the detail with which we will characterize extrasolar atmospheres with JWST, which will yield higher-quality spectra across a wider wavelength range.
AB - We present an atmospheric retrieval analysis of a pair of highly variable, ∼200 Myr old, early T type planetary-mass exoplanet analogs SIMP J01365662+0933473 and 2MASS J21392676+0220226 using the Brewster retrieval framework. Our analysis, which makes use of archival 1-15 μm spectra, finds almost identical atmospheres for both objects. For both targets, we find that the data is best described by a patchy, high-altitude forsterite (Mg2SiO4) cloud above a deeper, optically thick iron (Fe) cloud. Our model constrains the cloud properties well, including the cloud locations and cloud particle sizes. We find that the patchy forsterite slab cloud inferred from our retrieval may be responsible for the spectral behavior of the observed variability. Our retrieved cloud structure is consistent with the atmospheric structure previously inferred from spectroscopic variability measurements, but clarifies this picture significantly. We find consistent C/O ratios for both objects, which supports their formation within the same molecular cloud in the Carina-Near moving group. Finally, we note some differences in the constrained abundances of H2O and CO, which may be caused by data quality and/or astrophysical processes such as auroral activity and their differing rotation rates. The results presented in this work provide a promising preview of the detail with which we will characterize extrasolar atmospheres with JWST, which will yield higher-quality spectra across a wider wavelength range.
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U2 - 10.3847/1538-4357/acab58
DO - 10.3847/1538-4357/acab58
M3 - Article
AN - SCOPUS:85148864142
SN - 0004-637X
VL - 944
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 138
ER -