Jonathan Tennyson

Abstract: We report the analysis of two new spectroscopic observations of the super-Earth 55 Cancri e, in the near infrared, obtained with the WFC3 camera onboard the HST. 55 Cancri e orbits so close to its parent star, that temperatures much higher than 2000 K are expected on its surface. Given the brightness of 55 Cancri, the observations were obtained in scanning mode, adopting a very long scanning length and a very high scanning speed. We use our specialized pipeline to take into account systematics introduced by these observational parameters when coupled with the geometrical distortions of the instrument. We measure the transit depth per wavelength channel with an average relative uncertainty of 22 ppm per visit and find modulations that depart from a straight line model with a 6$\sigma$ confidence level. These results suggest that 55 Cancri e is surrounded by an atmosphere, which is probably hydrogen-rich. Our fully Bayesian spectral retrieval code, T-REx, has identified HCN to be the most likely molecular candidate able to explain the features at 1.42 and 1.54 $\mu$m. While additional spectroscopic observations in a broader wavelength range in the infrared will be needed to confirm the HCN detection, we discuss here the implications of such result. Our chemical model, developed with combustion specialists, indicates that relatively high mixing ratios of HCN may be caused by a high C/O ratio. This result suggests this super-Earth is a carbon-rich environment even more exotic than previously thought.

TL;DR: In this paper , the rotation-vibration-electronic (rovibronic) line lists for calcium monohydride (40Ca1H) and magnesium mg1H and its minor isotopologues were presented.

TL;DR: In this paper, the neutral-neutral and ion-neutral reactions of Mu, Mu+, HMu, and HMu+ with H, H2, H+2, and H+3 were considered.

TL;DR: In this article, the CO+ cation was studied as a function of internuclear distances in the range 1.7-3.0 a(0), and R-matrix wavefunctions were constructed for 1Sigma(+), (2)Pi,(2)Delta and 4Pi total symmetries by study of collisions of electrons with a CO2+ target.

TL;DR: In this paper, a hydrogen cyanide line list (MOMeNT-90) developed for the HITRAN spectroscopic database covering 0-7500 cm − 1 range (λ > 1330 nm) is presented, which is a combination of variationally calculated line intensities with line centers obtained from experimentally derived energy levels.