Infrared Transmission Spectra for Extrasolar Giant Planets

By Giovanna Tinetti, M. Liang, A. Vidal-Madjar, David Ehrenreich, A. Lecavelier des Etangs, Yuk L. Yung. 2006

71 citations recorded by the source corpus.

Among the hot Jupiters known to date that transit their parent stars, the two best candidates to be observed with transmission spectroscopy in the mid-infrared (MIR) are HD 189733b and HD 209458b, due to their combined characteristics of planetary density, orbital parameters, and parent star distance and brightness. Here we simulate transmission spectra of these two planets during their primary transit in the MIR, and we present sensitivity studies of the spectra to the changes of atmospheric thermal properties, molecular abundances, and C/O ratios. Our model predicts that the dominant species absorbing in the MIR on hot Jupiters are water vapor and carbon monoxide, and their relative abundances are determined by the C/O ratio. Since the temperature profile plays a secondary role in the transmission spectra of hot Jupiters compared to molecular abundances, future primary transit observations in the MIR of those objects might offer insight on extrasolar giant planet atmospheric chemistry. We find here that the absorption features caused by water vapor and carbon monoxide in a cloud-free atmosphere are deep enough to be observable by the present and future generation of space-based observatories, such as Spitzer Space Telescope and James Webb Space Telescope. We discuss our results in light of the capabilities of these telescopes.

Subfields: Astronomy and Astrophysics

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In Astronomy and Astrophysics

1. N. Madhusudhan
2. Jon Fortney
3. A. Showman
4. M. Marley
5. D. Sing
6. J. D'esert
7. V. Parmentier
8. R. Freedman

Citations in the corpus

• Optimal estimation retrievals of the atmospheric structure and composition of HD 189733b from secondary eclipse spectroscopy (2011, methodology): “…upper layers of an exoplanetary atmosphere, have been measured in the near-, mid- and farinfrared (NIR, MIR and FIR, respectively) by both theHubble Space Telescope (HST ) (Swain et al. 2008; Sing et al. 2009) andSpitzer telescope (Tinetti et al. 2007a; Beaulieu et al. 2008; Désert et al. 2009).”
• DETECTION OF AN ATMOSPHERE AROUND THE SUPER-EARTH 55 CANCRI E (2015, background): “…(e.g. Redfield et al. 2008; Swain et al. 2010; Waldmann et al. 2012; Snellen et al. 2008, 2010, 2014; Bean et al. 2010, 2013) and from space (e.g. Charbonneau et al. 2002, 2005; Deming et al. 2005, 2011; Knutson et al. 2007, 2008; Tinetti et al. 2007b, 2010; Swain et al. 2008, 2009a,b, 2013).”
• SEARCH FOR CARBON MONOXIDE IN THE ATMOSPHERE OF THE TRANSITING EXOPLANET HD 189733b (2009, background): “3, we describe the model and techniques used to estimate the physical and orbital parameters of HD189733b.”
• TRANSMISSION SPECTRA OF THREE-DIMENSIONAL HOT JUPITER MODEL ATMOSPHERES (2009, methodology): “This is true for their optical spectrum of HD 189733b shown in Pont et al. (2008), as well as the mid-infrared spectra for HD 189733b and HD 209458b from Tinetti et al. (2007a), even when we use the Tinetti et al. (2007a)P-T profiles.”