Experimental energy levels of 12C14N through marvel analysis

Syme, Anna-Maree; McKemmish, Laura K.

doi:10.1093/mnras/staa2791

Cited by 19 publications

(6 citation statements)

References 97 publications

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“…The molecules and opacity sources we include are H 2 O, CO, CO 2 , SO 2 , CH 4 , HCN, H 2 S, CH 3 , C 2 H 2 , C 2 H 4 , CN, CH, OH, and SH (Harris et al 2006;Rothman et al 2010;Barber et al 2014;Brooke et al 2014Brooke et al , 2016Masseron et al 2014;Yurchenko & Tennyson 2014;Azzam et al 2016;Underwood et al 2016;Chubb et al 2018Chubb et al , 2020Polyansky et al 2018;Yousefi et al 2018;Adam et al 2019;Gorman et al 2019;Bernath 2020;Syme & McKemmish 2020;Yurchenko et al 2020). We have three sets of synthetic spectra: one each for the morning and evening thermal profiles, plus a set of spectra that are the mean of the morning and evening spectra (corresponding to the transmission spectrum that would be observed during transit).…”

Section: Modeling Detailsmentioning

confidence: 99%

Volatile-to-sulfur Ratios Can Recover a Gas Giant’s Accretion History

Crossfield

2023

ApJL

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The newfound ability to detect SO2 in exoplanet atmospheres presents an opportunity to measure sulfur abundances and so directly test between competing modes of planet formation. In contrast to carbon and oxygen, whose dominant molecules are frequently observed, sulfur is much less volatile and resides almost exclusively in solid form in protoplanetary disks. This dichotomy leads different models of planet formation to predict different compositions of gas giant planets. Whereas planetesimal-based models predict roughly stellar C/S and O/S ratios, pebble-accretion models more often predict superstellar ratios. To explore the detectability of SO2 in transmission spectra and its ability to diagnose planet formation, we present a grid of atmospheric photochemical models and corresponding synthetic spectra for WASP-39b (where SO2 has been detected). Our 3D grid contains 113 models (spanning 1–100× the solar abundance ratio of C, O, and S) for thermal profiles corresponding to the morning and evening terminators, as well as mean terminator transmission spectra. Our models show that for a WASP-39b-like O/H and C/H enhancement of ∼10× solar, SO2 can only be seen for C/S and O/S ≲ 1.5× solar, and that WASP-39b’s reported SO2 abundance of 1–10 ppm may be more consistent with planetesimal accretion than with pebble-accretion models (although some pebble models also manage to predict similarly low ratios). More extreme C/S and O/S ratios may be detectable in higher-metallicity atmospheres, suggesting that smaller and more metal-rich gas and ice giants may be particularly interesting targets for testing planet formation models. Future studies should explore the dependence of SO2 on a wider array of planetary and stellar parameters, both for the prototypical SO2 planet WASP-39b, as well as for other hot Jupiters and smaller gas giants.

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Section: Modeling Detailsmentioning

confidence: 99%

Volatile-to-sulfur Ratios Can Recover a Gas Giant’s Accretion History

Crossfield

2023

ApJL

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“…The construction of the communicated molecular CN line strengths "CNv-lsf" [20] first, makes use of Wigner-Witmer eigenfunctions and a diatomic line position fitting program, second, computes Frank-Condon factors and r-centroids, and third, combines these factors with the rotational factors that usually decouple from the overall molecular line-strength due to the symmetry of diatomic molecules. In turn, the ExoMol states and transition files for CN [4,30,31] and the PGOPHER data file [32] are examined in order to generate line strength data that can be used with BESP and NMT. The LIFBASE program is utilized for visual comparisons of CN B-X simulated and recorded data.…”

Section: Line Positions and Strengths Of Diatomic Spectramentioning

confidence: 99%

Cyanide Molecular Laser-Induced Breakdown Spectroscopy with Current Databases

Parigger¹

2023

Preprint

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This work discusses diatomic molecular spectroscopy of laser-induced plasma and analysis of data records, specifically signatures of cyanide, CN. Line strength data from various databases are compared for simulation of the CN, B2Σ+⟶X2Σ+, Δv=0 sequence. Of interest are recent predictions using an astrophysical database, i.e., ExoMol, a laser-induced fluorescence database, i.e., LIFBASE, and a program for simulating rotational, vibrational and electronic spectra, i.e., PGOPHER. Cyanide spectra that are predicted from these databases are compared with line strength data that are in use by the author for the last three decades in the analysis of laser-plasma emission spectra. Comparisons with experimental laser-plasma records are communicated as well, and for spectral resolutions of 33 and 110 picometer. The accuracy of the CN line strength data is better than one picometer. Laboratory experiments utilize 308-nm, 35-picosecond bursts within an overall 1-nanosecond pulse-width, and 1064-nm, 6-ns pulse-width radiation. Experimental results are compared with predictions. Differences of the databases are elaborated for equilibrium of rotational and vibrational modes and at an internal, molecular temperature of the order of 8,000 Kelvin. Applications of accurate CN data include for example combustion diagnosis, chemistry, and supersonic and hypersonic expansion diagnosis. The cyanide molecule is also of interest in the study of astrophysical phenomena.

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“…For the three electronic states considered in this line list, we show the distribution of sources used in our final states file in Figure 4. Relatively few Mollist energies are included, probably due to the breadth of energy levels empirically determined in our Marvel study (Syme & McKemmish 2020b).…”

Section: Energy Levelsmentioning

confidence: 99%

“…In the case of CN, we need to consider at least the three lowest lying electronic states, the X 2 Σ + ground state, the A 2 Π state at 9243 cm −1 , and the B 2 Σ + state at 25752 cm −1 , as astrophysical observations of interactions between all of these electronic bands have been observed (Hamano et al 2019). All available experimental data was recently compiled for 12 C 14 N (Syme & McKemmish 2020b), which then used the Marvel (Furtenbacher et al 2007) procedure to extract empirical energy levels.…”

Section: Introductionmentioning

confidence: 99%

“…PL = 4, PR = 4, NL = 4 for all states while NR = 8, 5 and 10 for the X 2 Σ + , A 2 Π and B 2 Σ + states respectively. The parameters of these functions are fit using Duo to minimise the difference between the Duo-predicted variational energy levels and the available Marvel experimentallyderived energy levels (Syme & McKemmish 2020b). Duo uses a grid-based sinc DVR method to solve the coupled Schrodinger equation; for our calculations, we use grid of uniformly distributed 1001 points from 0.6-4.0 Å.…”

Section: Introductionmentioning

confidence: 99%

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Full Spectroscopic Model and Trihybrid Experimental-Perturbative-Variational Line List for CN

Syme,

McKemmish

2021

Preprint

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Accurate line lists are important for the description of the spectroscopic nature of small molecules. While a line list for CN (an important molecule for chemistry and astrophysics) exists, no underlying energy spectroscopic model has been published, which is required to consider the sensitivity of transitions to a variation of the proton-to-electron mass ratio.Here we have developed a Duo energy spectroscopic model as well as a novel hybrid style line list for CN and its isotopologues, combining energy levels that are derived experimentally (Marvel), using the traditional/perturbative approach (Mollist), and the variational approach (from a Duo spectroscopic model using standard ExoMol methodology). The final Trihybrid ExoMol-style line list for 12 C 14 N consists of 28,004 energy levels (6,864 experimental, 1,574 perturbative, the rest variational) and 2,285,103 transitions up to 60,000 cm −1 between the three lowest electronic states (X 2 Σ + , A 2 Π, and B 2 Σ + ). The spectroscopic model created is used to evaluate CN as a molecular probe to constrain the variation of the proton-to-electron mass ratio; no overly promising sensitive transitions for extragalactic study were identified.

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Experimental energy levels of 12C14N through marvel analysis

Cited by 19 publications

References 97 publications

Volatile-to-sulfur Ratios Can Recover a Gas Giant’s Accretion History

Volatile-to-sulfur Ratios Can Recover a Gas Giant’s Accretion History

Cyanide Molecular Laser-Induced Breakdown Spectroscopy with Current Databases

Full Spectroscopic Model and Trihybrid Experimental-Perturbative-Variational Line List for CN

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