ExoMol molecular line lists – X. The spectrum of sodium hydride

Abstract

Accurate and complete rotational, rotational-vibrational and rotational-vibrationalelectronic line lists are calculated for sodium hydride: both the NaH and NaD isotopologues are considered. These line lists cover all ro-vibrational states of the ground (X 1 Σ + ) and first excited (A 1 Σ + ) electronic states. The calculations use available spectroscopically-determined potential energy curves and new high-quality, ab initio dipole moment curves. Partition functions for both isotopologues are calculated and the effect of quasibound states is considered. The resulting line lists are suitable for temperatures up to about 7000 K and are designed for studies of exoplanet atmospheres, brown dwarfs and cool stars. In particular, the NaH A − X band is found to show a broad absorption feature at about 385 nm which should provide a signature for the molecule. All partition functions, lines and transitions are available as Supplementary Information to this article and at www.exomol.com.

EXOCROSS: a general program for generating spectra from molecular line lists

“…10. Overview of the absorption line intensities of NaH at T =2000 K computed using the line list of Rivlin et al (2015). the column number 10 (see Table 5), which can be used to generate absorption cross section of NO for the overtone band = 5, i.e.…”

“…Another typical example is to generate cross sections for specific electronic bands, see Fig. 10, where an overview of three absorption electronic bands X-X, A-X, A-A of NaH is shown (Rivlin et al 2015).…”

New avenues for thermal inversions in atmospheres of hot Jupiters

“…This is done through our self-consistent radiative-convective equilibrium code GENESIS . Key to this new find has been the molecular cross sections generated from the latest and most accurate line lists available (Hill et al 2013;McKemmish et al 2016;Patrascu et al 2015;Yurchenko et al 2016;Rivlin et al 2015;Yadin et al 2012).…”

ExoMol molecular line lists – XIII. The spectrum of CaO

“…CaO is one of a number of molecules which may be observable constituents of hot, rocky exoplanets. The ExoMol project has already provided linelists for a number of other, similar molecules including MgH and CaH (Yadin et al 2012), SiO (Barton et al 2013), NaCl and KCl (Barton et al 2014), AlO (Patrascu et al 2015), ScH (Lodi et al 2015) and NaH (Rivlin et al 2015). A number of other potentially important species, including VO (McKemmish et al 2015), TiO, TiH, NiH and CrH (Gorman et al 2016), are currently being studied.…”