ExoMol molecular line lists XXX: a complete high-accuracy line list for water

Abstract

A new line list for H 2 16 O is presented. This line list, which is called POKAZATEL, includes transitions between rotation-vibrational energy levels up to 41 000 cm −1 in energy and is the most complete to date. The potential energy surface (PES) used for producing the line list was obtained by fitting a high-quality ab initio PES to experimental energy levels with energies of 41 000 cm −1 and for rotational excitations up to J = 5. The final line list comprises all energy levels up to 41 000 cm −1 and rotational angular momentum J up to 72. An accurate ab initio dipole moment surface (DMS) was used for the calculation of line intensities and reproduces high-precision experimental intensity data with an accuracy close to 1%. The final line list uses empirical energy levels whenever they are available, to ensure that line positions are reproduced as accurately as possible. The POKAZATEL line list contains over 5 billion transitions and is available from the ExoMol website (www.exomol.com) and the CDS database.

Calculated line lists for H216O and H218O with extensive comparisons to theoretical and experimental sources including the HITRAN2016 database

“…We continue to investigate this problem. Intensity measurements of the ν 3 fundamental which were recently made by Devi et al [23] to the measurements of (a) Loos et al [6], Birk et al [34,35] and (b) Ptashnik et al [14]. Uncertainties on this work for (a) are a combination of PES stability and experiment, while POKAZATEL ratios shown in (a) only carry experimental uncertainty.…”

“…Comparing to the HITRAN2016 database, we match to 793 transitions that originate from the work of Toth et al [3], see Figure 4a [23] to the experimental measurements of (a) Toth et al [3] and (b) Sironneau and Hodges [13]. The uncertainty on our work is calculated from PES stability factor.…”

“…Comparison of the calculated intensities in our new line list and POKAZATEL[23] to the experimental data of (a) Mikhailenko et al[9], (b) Leshchishina et al[8], (c) Regalia et al[11] and (d) Campargue et al[12] that are all in HITRAN2016. Error bars on our work are from the PES stability factors.…”

A new set of atmosphere and evolution models for cool T–Y brown dwarfs and giant exoplanets

“…For example, a 1 M Jup object is cooler and less luminous at ages < 0.1 Gyr, and warmer and brighter for ages > 0.1 Gyr compared to the previous AMES-Cond models. We note that line lists of important molecular absorbers are being continuously updated and improved, and we are working on integrating new H 2 O (Polyansky et al 2018) Fig. 18.…”

A weak spectral signature of water vapour in the atmosphere of HD 179949 b at high spectral resolution in the L band

“…Some of the most up-to-date high resolution line list data were used for each species; CH 4 was taken from HI-TRAN 2016 (Gordon et al 2017) and H 2 O and CO 2 taken from the high temperature HITEMP 2010 (Rothman et al 2010) database. We also generated single molecular models of the new and more complete water line list, POKAZA-TEL (Polyansky et al 2018), from the ExoMol database as a comparison to HITEMP regularly used in past HRS observations.…”