A consistent retrieval analysis of 10 hot Jupiters observed in transmission
American Astronomical Society / IOP Publishing
© 2017. The American Astronomical Society. All rights reserved.
We present a consistent optimal estimation retrieval analysis of 10 hot Jupiter exoplanets, each with transmission spectral data spanning the visible to near-infrared wavelength range. Using the NEMESIS radiative transfer and retrieval tool, we calculate a range of possible atmospheric states for WASP-6b, WASP-12b, WASP-17b, WASP- 19b, WASP-31b, WASP-39b, HD 189733b, HD 209458b, HAT-P-1b, and HAT-P-12b. We find that the spectra of all 10 planets are consistent with the presence of some atmospheric aerosol; WASP-6b, WASP-12b, WASP-17b, WASP-19b, HD 189733b, and HAT-P-12b are all fit best by Rayleigh scattering aerosols, whereas WASP-31b, WASP-39b and HD 209458b are better represented by a gray cloud model. HAT-P-1b has solutions that fall into both categories. WASP-6b, HAT-P-12b, HD 189733b, and WASP-12b must have aerosol extending to low atmospheric pressures (below 0.1 mbar). In general, planets with equilibrium temperatures between 1300 and 1700 K are best represented by deeper, gray cloud layers, whereas cooler or hotter planets are better fit using high Rayleigh scattering aerosol. We find little evidence for the presence of molecular absorbers other than H2O. Retrieval methods can provide a consistent picture across a range of hot Jupiter atmospheres with existing data, and will be a powerful tool for the interpretation of James Webb Space Telescope observations
J.K.B. is currently funded under European Research Council project 617119 (ExoLights). J.K.B. also acknowledges the support of the Science and Technology Facilities Council during earlier stages of this work. S.A. acknowledges the support of the Leverhulme Trust (RPG- 2012-661) and S.A. and P.G.J.I. receive funding from the Science and Technology Facilities Council (ST/K00106X/1). D.K.S. acknowledges support from the European Research Council under the European Unions Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement number 336792. This work is based on observations with the NASA/ESA HST, obtained at the Space Telescope Science Institute (STScI) operated by AURA, Inc. This work is also based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.
This is the final version of the article. Available from the publisher via the DOI in this record.
Vol. 834, 50