Radiative lifetimes and cooling functions for astrophysically important molecules

Abstract

Extensive line lists generated as part of the ExoMol project are used to compute lifetimes for individual rotational, rovibrational and rovibronic excited states, and temperature-dependent cooling functions by summing over all dipole-allowed transitions for the states concerned. Results are presented for SiO, CaH, AlO, ScH, H${}_2$O and methane. The results for CH${}_4$ are particularly unusual with 4 excited states with no dipole-allowed decay route and several others where these decays lead to exceptionally long lifetimes. These lifetime data should be useful in models of masers and estimates of critical densities, and can provide a link with laboratory measurements. Cooling functions are important in stellar and planet formation.

16 pages, 10 figures

References in corpus (15)

• ExoMol line lists IV: The rotation-vibration spectrum of methane up to 1500 K
• ExoMol line lists VII: The rotation-vibration spectrum of phosphine up to 1500 K
• ExoMol molecular line lists V: The ro-vibrational spectra of NaCl and KCl
• ExoMol molecular line lists: IX The spectrum of AlO
• High accuracy CO${}_2$ line intensities determined from theory and experiment
• The spectrum of hot methane in astronomical objects using a comprehensive computed line list
• ExoMol molecular line lists - XIII: The spectrum of CaO
• ExoMol molecular line lists X: The spectrum of sodium hydride
• The calculated rovibronic spectrum of scandium hydride, ScH
• ExoMol molecular line lists XII: Line Lists for 8 isotopologues of CS
• Exomol molecular line lists VI: A high temperature line list for Phosphorus Nitride
• The rovibrational spectrum of BeH, MgH and CaH at high temperatures in the $X{}^2{\Sigma }^{+}$ state: a theoretical study
• ExoMol molecular line lists: XI The spectrum of nitric acid
• Hybrid variation-perturbation method for calculating rovibrational energy levels of polyatomic molecules
• The Status of Spectroscopic Data for the Exoplanet Characterisation Missions

Cited by in corpus (35)

• The ExoMol database: molecular line lists for exoplanet and other hot atmospheres
• ExoMol molecular line lists - XVI: The rotation-vibration spectrum of hot H${}_2$S
• The 2020 release of the ExoMol database: molecular line lists for exoplanet and other hot atmospheres
• Duo: a general program for calculating spectra of diatomic molecules
• ExoCross: a general program for generating spectra from molecular line lists
• ExoMol molecular line lists - XIV: The rotation-vibration spectrum of hot SO${}_2$
• ExoMol molecular line lists - XXIII: spectra of PO and PS
• Perspective: Accurate ro-vibrational calculations on small molecules
• The ExoMol project: Software for computing large molecular line lists
• ExoMol line lists XXIV: A new hot line list for silicon monohydride, SiH
• ExoMol Line List XXI: Nitric Oxide (NO)
• The {\it ab initio} calculation of spectra of open shell diatomic molecules
• ExoMol line lists -- XLIV. IR and UV line list for silicon monoxide (SiO)
• ExoMol molecular line lists XX: a comprehensive line list for H${}_3^{+}$
• Laboratory spectra of hot molecules: data needs for hot super-Earth exoplanets
• Direct Detection of Spin-(In)dependent Nuclear Scattering of Sub-GeV Dark Matter Using Molecular Excitations
• ExoMol molecular line lists XXXVI: $X{}^2\Pi -X{}^2\Pi$ and $A{}^2{\Sigma }^{+}-X{}^2\Pi$ transitions of SH
• ExoMol line lists - XXXII. The rovibronic spectrum of MgO
• ExoMol molecular line lists - XXVI: spectra of SH and NS
• ExoMol line lists XV: A new hot line list for hydrogen peroxide
• Spectroscopy of YO from first principles
• ExoMol line lists -- LVI: The SO line list, MARVEL analysis of experimental transition data and refinement of the spectroscopic model
• Predicted Landé $g$-factors for open shell diatomic molecules
• Empirical Line Lists in the ExoMol Database
• Ab initio calculations to support accurate modelling of the rovibronic spectroscopy calculations of vanadium monoxide (VO)
• Rovibronic spectroscopy of PN from first principles
• Data structures for photoabsorption within the ExoMol project
• Ultrafast intermolecular energy transfer from vibrations to electronic motion
• PyExoCross: a Python program for generating spectra and cross-sections from molecular line lists
• ExoMol line lists -- {XLVI}: Empirical rovibronic spectra of silicon mononitrate (SiN) covering the 6 lowest electronic states and 4 isotopologues
• Cascade infrared thermal photon emission
• Radiative cooling of H3O+ and its deuterated isotopologues
• Simulating electric field interactions with polar molecules using spectroscopic databases
• Efficient non-resonant intermolecular vibrational energy transfer
• Disentangling the molecular nature of the benchmark molecule H2O2 through many-body fragmentation dynamics