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A new look at NICMOS transmission spectroscopy: No conclusive evidence for molecular features

Published online by Cambridge University Press:  10 November 2011

Neale P. Gibson ,
Frederic Pont  and
Suzanne Aigrain
Neale P. Gibson
Affiliation:
Department of Physics, University of Oxford, email: [email protected]
Frederic Pont
Affiliation:
School of Physics, University of Exeter
Suzanne Aigrain
Affiliation:
Department of Physics, University of Oxford, email: [email protected]
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Abstract

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We present a re-analysis of archival HST/NICMOS transmission spectroscopy of the exoplanet system, HD 189733, from which detections of several molecules have been claimed. As expected, we can replicate the transmission spectrum previously published when we use an identical model for the systematic effects, although the uncertainties are larger as we use a residual permutation algorithm in an effort to account for instrumental systematics. We also find that the transmission spectrum is considerably altered when slightly changing the instrument model, and conclude that the NICMOS transmission spectrum is too dependent on the method used to remove systematics to be considered a robust detection of molecular species, given that there is no physical reason to believe that the baseline flux should be modelled as a linear function of any chosen set of parameters.

Keywords

stars: individual (HD 189733)planetary systemstechniques: spectroscopic
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 6 , Symposium S276: The Astrophysics of Planetary Systems: Formation, Structure, and Dynamical Evolution , October 2010 , pp. 478 - 479
Copyright
Copyright © International Astronomical Union 2011

References

Brown, T. M. 2001, ApJ, 553, 1006CrossRefGoogle Scholar
Deroo, P., Swain, M. R., & Vasisht, G. 2010, arXiv:1011.0476v1Google Scholar
Gibson, N. P., Pont, F., & Aigrain, S. 2011, MNRAS, 411, 2199CrossRefGoogle Scholar
Seager, S. & Sasselov, D. D. 2000, ApJ, 537, 916CrossRefGoogle Scholar
Swain, M. R., Vasisht, G., & Tinetti, G. 2008, Nature, 452, 329CrossRefGoogle Scholar
Tinetti, G., Deroo, P., Swain, M. R., et al. 2010, ApJ, 712, L139CrossRefGoogle Scholar