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REVIEW 3 major objections 6 minor 59 references

PDRs4All XV: CH radical and H$_3^+$ molecular ion in the irradiated protoplanetary disk d203-506

T0 review · 3 major / 6 minor · reviewed 2026-08-07 · deepseek-v4-flash

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Pith's one-line read This paper claims that JWST observations of the irradiated Orion disk d203-506 reveal the CH radical and, likely, the H$_3^+$ molecular ion, with H$_3^+$ formed by ultraviolet-driven chemistry rather than cosmic-ray ionization.

desk verdict Solid CH detection, but the headline H3+ claim is still a candidate, not a secure detection. read the letter →

arxiv 2506.05186 v2 pith:7KPSQB4E submitted 2025-06-05 astro-ph.GA

I. Schroetter , O. Berné , J. R. Goicoechea , J. H. Black , O. Roncero , F. Alarcon , P. Amiot , O. Asvany
show 15 more authors
C. Boersma S. Brünken J. Cami L. Coudert E. Dartois A. Fuente B. Gans A. Gusdorf U. Jacovella M. A. Martin Drumel T. Onaka E. Peeters E. Roueff A. G. G. M. Tielens M. Zannese
This is my paper
classification astro-ph.GA
keywords CHradicalH3+molecularionprotoplanetarydiskJWSTNIRSpecphotodissociationregionUV-drivenchemistryionsPAHTATmol
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper reports the first claimed detections of the methylidyne radical (CH) and the trihydrogen cation (H$_3^+$) in a protoplanetary disk, using a JWST-NIRSpec spectrum of the strongly UV-irradiated Orion disk d203-506. CH is clearly detected at signal-to-noise 48 in its 3.3 $\mu$m ro-vibrational emission, while H$_3^+$ is likely detected at signal-to-noise 8 through several $\nu_2 = 1 \to 0$ lines and a stacked residual feature at zero velocity. The authors estimate CH and H$_3^+$ abundances of a few $10^{-7}$ and about $10^{-8}$ relative to hydrogen nuclei. CH fits standard hydrocarbon photochemistry in the disk's photodissociation region, but H$_3^+$ is usually attributed to cosmic-ray ionization of H$_2$; here the authors argue instead for a UV-driven formation route in dense, strongly irradiated gas. If correct, these detections show that ultraviolet radiation alone can drive the chemistry of key molecular ions in planet-forming disks.

What carries the argument

The load-bearing tool is PAHTATmol (Polycyclic Aromatic Hydrocarbons Toulouse Astronomical Templates with Molecules), a fitting engine that models a JWST spectrum as a linear combination of PAH band Gaussians, stellar and dust continuum blackbodies, atomic and H$_2$ lines, and LTE ro-vibrational emission from 19 small molecules, radicals, and ions. Molecular templates are precomputed with a spectroscopic simulation program at 300, 500, 1000, 1500, and 2000 K from laboratory line lists, and the fit uses non-negative least squares. Detection is judged by a signal-to-noise ratio computed from the fitted line peaks divided by the local residual scatter, with a threshold of S/N > 5; CH scores 48 and H$_3^+$ scores 8. For the weakest species the paper adds a stacking step in which residual spectra around the predicted H$_3^+$ lines are co-added, converting a set of near-threshold line candidates into a single visible emission feature at zero velocity.

What would settle it

Compute the $\nu_2$ band spectrum of H$_3^+$ with a non-LTE excitation model that includes chemical formation pumping and FUV radiative pumping at the densities and radiation field of d203-506 ($n_{\rm H} \simeq 10^7$ cm$^{-3}$, $G_0 = 2\times 10^4$), and compare its predicted ratios among R(1,0), Q(1,0), Q(5,G), R(7,0), and R(7,6)u with the observed residual spectrum; if no single physical model reproduces the stacked feature and its line ratios, the identification fails. A complementary check is higher-resolution spectroscopy of those lines to verify the feature sits at zero velocity with the disk's line profile rather than at the position of a residual spike from a modeled species.

Watch

Extended reading notes

Core claim

The paper's central claim, stated in the conclusion, is that two molecules are newly detected in a protoplanetary disk: the CH radical and the H$_3^+$ molecular ion. In the NIRSpec f290lp spectrum of d203-506, fitted with the multi-molecule LTE tool PAHTATmol, CH appears as clear ro-vibrational emission around 3.3 $\mu$m with $T \simeq 2000$ K, $N(\mathrm{CH}) = 4.5\times 10^{14}$ cm$^{-2}$, and a derived abundance of a few $10^{-7}$; its spatial emission peaks slightly deeper in the disk than CH$^+$ and CH$_3^+$, consistent with formation by dissociative recombination of CH$_3^+$ and reactions of carbon atoms with vibrationally excited H$_2$. H$_3^+$ is detected as a likely set of $\nu_2 = 1\to 0$ lines, including R(1,0), Q(1,0), Q(5,G), R(7,0), and R(7,6)u, with $T \gtrsim 1000$ K, $N(\mathrm{H}_3^+) = 1.1\times 10^{13}$ cm$^{-2}$, and an abundance near $10^{-8}$; the stacked residual spectrum shows a clear feature at the expected zero-velocity position. Because H$_3^+$ emission peaks at the same bright spot as FUV-pumped H$_2$ and photodissociated OH, and because the companion photochemical model predicts $N(\mathrm{H}_3^+) \lesssim 10^{13}$ cm$^{-2}$ from UV-driven chemistry involving a hot water vapor reservoir, the authors favor a formation route largely independent of cosmic-ray ionization. This would be the first identification of H$_3^+$ in a protoplanetary disk.

Load-bearing premise

The H$_3^+$ detection stands only if the PAHTATmol model of everything else in the spectrum — PAH bands, continuum, and the other 18 molecules — leaves clean residuals at the H$_3^+$ wavelengths; any error in that global model at those positions could manufacture the weak, S/N=8 features.

Editorial extensions

If this is right

  • CH and H$_3^+$ should be sought in the JWST spectra of other strongly irradiated protoplanetary disks, where the same UV-driven chemistry is expected to operate.
  • A confirmed H$_3^+$ detection in d203-506 would break the usual assumption that interstellar H$_3^+$ traces cosmic-ray ionization; in dense, strongly FUV-irradiated gas, UV-driven routes through hot water vapor can dominate instead.
  • The vibrationally hot H$_3^+$ lines require a non-LTE explanation, since radiative rates near 100 s$^{-1}$ cannot be thermalized at densities of about $10^7$ cm$^{-3}$; this motivates statistical-equilibrium models that include chemical and radiative pumping.
  • The CH column density inferred from LTE emission exceeds the photochemical model prediction by up to a factor of about five, pointing to additional CH formation routes or to radiative pumping of the observed levels.
  • The stacked H$_3^+$ spectrum provides a template that can be used to search for H$_3^+$ in other JWST data sets.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A reader should treat the H$_3^+$ identification as conditional on the global model subtraction; the decisive test, beyond stacking, is a dedicated non-LTE model of H$_3^+$ excitation, which the paper itself says is needed.
  • If CH ro-vibrational lines contribute at 3.3–3.4 $\mu$m, measurements of the 3.3 $\mu$m PAH band in irradiated disks may need to subtract CH, which could affect PAH abundance estimates in such objects.
  • The same fitting approach could be run on other targets in the observing program; a correlation between CH and H$_3^+$ emission strength and incident $G_0$ would test whether the UV-driven formation route scales as predicted.
  • H$_3^+$ emission co-located with OH from water photodissociation suggests the ion could serve as a marker for UV-illuminated water destruction in disks, connecting molecular-ion chemistry to the water reservoir available for planet formation.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 6 minor

Summary. The manuscript presents an analysis of the JWST/NIRSpec spectrum of the irradiated protoplanetary disk d203-506 using a new multi-molecule fitting tool, PAHTATmol. The authors report a clear detection of the CH radical (S/N = 48) and a likely detection of H3+ (S/N = 8) via the ν2 band, with LTE column densities implying abundances of a few 10^-7 and ~10^-8, respectively. They interpret the CH emission as a product of hydrocarbon photochemistry in the disk PDR, and argue that the hot H3+ emission, if real, would favour UV-driven H3+ formation rather than cosmic-ray ionization. A companion photochemical model predicts N(H3+) ≲ 10^13 cm^-2, in agreement with the LTE estimate.

Significance. If confirmed, the H3+ detection would be the first in a protoplanetary disk and would provide direct evidence for UV-driven H3+ formation in strongly irradiated dense gas, a process of broad astrochemical interest. The CH detection is robust and is a valuable new tracer of hydrocarbon chemistry in disk PDRs. The paper introduces PAHTATmol, a fitting tool that integrates state-of-the-art laboratory spectroscopic data (ExoMol and literature constants) and simultaneously fits 19 molecular species; this tool will be useful for future JWST disk and PDR studies. The manuscript also makes a falsifiable prediction of the H3+ column density from a companion model rather than fitting the model to the H3+ lines, a strength of the paper.

major comments (3)
  1. [Sect. 4.2, Appendix B, Fig. 4] The H3+ detection rests entirely on the residual spectrum after subtracting the PAHTATmol global LTE model, yet the manuscript provides no control test to quantify the false-positive rate of the stacking procedure. The stack includes R(1,0), which is partially blended with CH (Sect. 4.2 and Table B.1), and the residual spectrum exhibits spikes from strong lines due to simplified excitation modeling (Sect. 3.2). Because the stacked feature is the primary evidence for H3+, the authors should demonstrate its robustness by (i) stacking an equal number of off-line positions to estimate the noise statistics, (ii) repeating the stack without the CH-blended R(1,0) line, and (iii) explicitly quantifying how uncertainties in the subtracted CH and other molecular models propagate into the H3+ residual. Without such tests, the nominal S/N = 8 does not establish a detection at the claimed confidence.
  2. [Eq. A.1, Appendix A.2] The detection significance defined in Eq. (A.1) uses the standard deviation of the residuals over ±10 pixels as the noise. These residuals are not white noise; they contain correlated structure from imperfect modeling of strong lines and PAH bands, as acknowledged in Sect. 3.2. Consequently, the S/N value is not a statistical significance in the usual sense, and the threshold S/N > 5 does not control the false-discovery rate of the multi-molecule search. The analysis should be supplemented with a Monte Carlo or bootstrap evaluation, or the noise should be estimated from line-free spectral regions, before H3+ can be claimed at the stated confidence.
  3. [Section 5, abstract, Section 4.2] The conclusion states 'We claim the detection of two new molecules in a protoplanetary disk: ... CH and ... H3+', but the abstract and Section 4.2 describe H3+ as a 'likely detection' whose lines are 'weak and lie near the detection threshold' and whose presence is 'open to interpretation' because of blends. Given that the H3+ case depends on the residual-subtraction tests requested above, the conclusion should either be revised to state explicitly that H3+ is tentatively detected pending further modelling, or the manuscript should provide the control tests that would justify the stronger wording. This distinction matters because the UV-formation interpretation is predicated on the H3+ detection.
minor comments (6)
  1. [Eq. A.1] Equation (A.1) is typeset incorrectly in the manuscript (the square root symbol renders as 'vtX'), making the formula difficult to read; please correct the typesetting.
  2. [Abstract] In the abstract, the verb 'underscore' should be 'underscores' to agree with the singular subject 'Our detection'.
  3. [Introduction] The chemical formula 'C 2H +2' appears with awkward spacing; please check the formatting (likely C2H2+).
  4. [Fig. 1 caption] The caption contains 'di fferent' with a spurious space; it should read 'different'.
  5. [References] The reference to Berné et al. (2023) is given in the list with a URL rather than a standard journal citation; it should be formatted consistently with the other references.
  6. [Appendix A.1] The software name 'pgopher' should be capitalized consistently (PGOPHER) when referring to the program.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the CH and H3+ detections are based on independent laboratory spectroscopic data and a data-fitting tool, not on the claimed results.

full rationale

The paper's central claims are the detections of CH and H3+ in the protoplanetary disk d203-506, derived by fitting the JWST-NIRSpec spectrum with the PAHTATmol tool. The molecular emission templates are computed from independent laboratory spectroscopic constants and databases (e.g., ExoMol via Mizus et al. 2017 and Bowesman et al. 2023 for H3+; Masseron et al. 2014 for CH), not from the observed d203-506 spectrum. The fitted LTE column densities and excitation temperatures are outputs of the fit, not inputs that presuppose the detections. The H3+ detection is admittedly weak (S/N=8) and relies on residual subtraction after removing a global model including other molecules; this is a statistical and systematic uncertainty, but it is not a definitional circularity because the residual feature is compared against the laboratory line positions and relative intensities, and the stacking procedure does not force a feature at zero velocity by construction. The companion paper by Goicoechea et al. (2025) predicts an H3+ column density of ≲1e13 cm-2 from a PDR chemical model with stated assumptions (G0=2e4, nH=1e7 cm-3); that prediction is independent of the H3+ line detections reported here, and its agreement with the LTE estimate is presented as an external comparison, not as an input to the detection. The use of the H2 column density from Berné et al. (2024) for abundance scaling is a previously measured quantity from the same team, but it does not enter the detection significance or the line identification, so it is not load-bearing for the central claim. No equation or fitting step in the paper defines a 'prediction' in terms of the fitted quantity itself, and no self-citation is used to forbid alternative interpretations. The limitations noted in the paper (simplified LTE excitation, residual spikes, blended lines) are candidly stated and affect the robustness of the H3+ detection, but they do not make the derivation circular.

Assumptions & free parameters 5 free parameters · 5 assumptions · 0 invented entities

The central detection claims rest on the fitted LTE temperatures and column densities, plus the accuracy of the global continuum/PAH subtraction. The abundance estimates additionally assume a simple N(H)=N(H2) conversion. No new physical entities are introduced; all species are known molecules with laboratory line lists.

free parameters (5)
  • LTE excitation temperature (Tex) for each detected molecule = CH ~2000 K; CO 1000/2000 K; H3+ 1000/2000 K; OH ~1000-2000 K
    Free parameter in the LTE fit; directly sets line intensity ratios and therefore the derived column density.
  • LTE column density N for each molecule = CH 4.5e14 cm^-2; H3+ 1.1e13 cm^-2
    Derived from the linear fit factor Fmol; abundance estimates scale linearly with N.
  • Two-temperature component weights for CO and H3+ = not specified
    A combination of T=1000 K and 2000 K is needed to fit the lines; adds two free parameters per species.
  • PAH emission Gaussians (number, amplitude, width) = not specified
    Broad Gaussians are fit to reproduce the 3.3-3.4 um PAH bands; subtraction quality directly affects the CH line fluxes.
  • Blackbody continuum parameters = not specified
    Stellar and dust continuum modeled as blackbodies; residuals affect all molecular line fits.
assumptions (5)
  • domain assumption Local thermodynamic equilibrium (LTE) with a single excitation temperature for each species
    Invoked in Sect. 3.1 for all species; the paper acknowledges non-LTE excitation is likely for CH and H3+ due to radiative pumping, which affects derived column densities.
  • domain assumption Single-slab radiative transfer
    Sect. 3.1: 'assuming single-slab radiative transfer.' Real disks have gradients; two-temperature fits are an attempt to capture this.
  • ad hoc to paper Detection threshold S/N > 5 (Eq. A.1)
    Appendix A.2: the threshold is defined by the authors; a different threshold would change which molecules are claimed detected.
  • domain assumption N(H) = N(H2) in the disk PDR for abundance conversion
    Sect. 4.1: used to convert CH and H3+ column densities to abundances; this ignores atomic hydrogen and introduces a factor-of-two ambiguity.
  • domain assumption H2 column density from Berné et al. (2024) is accurate for the same aperture
    Sect. 4.1: abundances are normalized to this previously published value; any error propagates linearly into the reported abundances.

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Cite this review

Pith. "Pith review of PDRs4All XV: CH radical and H$_3^+$ molecular ion in the irradiated protoplanetary disk d203-506." pith.science (2026). https://pith.science/paper/7KPSQB4E

@misc{pith2026250605186,
  author       = {Pith},
  title        = {Pith review of: PDRs4All XV: CH radical and H$_3^+$ molecular ion in the irradiated protoplanetary disk d203-506},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/7KPSQB4E}},
  note         = {Machine review of arXiv:2506.05186}
}
abstract

Most protoplanetary disks experience a phase in which they are subjected to strong ultraviolet radiation from nearby massive stars. This UV radiation can substantially alter their chemistry by producing numerous radicals and molecular ions. In this Letter we present detailed analysis of the JWST-NIRSpec spectrum of the d203-506 obtained as part of the PDRs4All Early Release Science program. Using state-of-the-art spectroscopic data, we searched for species using a multi-molecule fitting tool, PAHTATmol, that we developed for this purpose. Based on this analysis, we report the clear detection of ro-vibrational emission of the CH radical and likely detection of the H$_3^+$ molecular ion, with estimated abundances of a few times 10$^{-7}$ and approximately 10$^{-8}$, respectively. The presence of CH is predicted by gas-phase models and well explained by hydrocarbon photochemistry. H$_3^+$ is usually formed through reactions of H$_2$ with H$_2^+$ originating from cosmic ray ionization of H$_2$. However, recent theoretical studies suggest that H$_3^+$ also forms through UV-driven chemistry in strongly irradiated ($G_0>$10$^3$), dense ($n_{\rm H} >10^{6}$ cm$^{-3}$) gas. The latter is favored as an explanation for the presence of ``hot'' H$_3^+$ ($T_{\rm ex}\gtrsim$1000 K) in the outer disk layers of d203-506, coinciding with the emission of FUV-pumped H$_2$ and other ``PDR species'', such as CH$^+$, CH$_3^+$, and OH. Our detection of infrared emission from vibrationally excited H$_3^+$ and CH raises questions about their excitation mechanisms and, underscore that UV radiation can have a profound impact on the chemistry of planet forming disks. They also demonstrate the power of JWST pushing the limit for the detection of elusive species in protoplanetary disks.

Figures

Figures reproduced from arXiv: 2506.05186 by the authors.

Figure 1
Figure 1. Bottom panel: PAHTATmol shifted fit result (blue curve) on the NIRSpec f290lp filter spectrum of d203-506 (black curve). The different colors at the bottom of the panel show the inverted individual molecular spectra, and a dotted magenta line shows the atomic and H2 emission lines. Upper panel: Model residual (observed spectrum minus the model). 5 ◦25′05.47′′) on the northwestern tip of the disk facing the il￾lumina… view at source ↗
Figure 2
Figure 2. Near-infrared CH rovibrational emission in d203-506. The continuum-subtracted observations are shown in black, and the CH model—offset for clarity—is shown in orange. The dotted magenta lines indicate model spectra for additional species. (e.g., Gerin et al. 2010). We detect the CH ro-vibrational emis￾sion lines around 3.3 µmin the same wavelength range of the 3.3-3.4 µm PAH emission bands (C–H stretching). The dete… view at source ↗
Figure 3
Figure 3. IR JWST images of d203-506. Top left: NIRCam F182M (broad filter centered at 1.82 µm). Top right: NIRCam F212N (H2 1-0 S (1) emission). Bottom left: NIRSpec CH emission map, continuum sub￾tracted. Bottom right: NIRSpec Q(1,0) H + 3 emission map, continuum subtracted. All panels show F212N contours in white. in Appendix B). Table B.1 summarizes the transition properties. Other expected H + 3 lines are blended with em… view at source ↗
Figures from the paper (1 more)
Figure 4
Figure 4. Figure 4: H + 3 lines in d203-506. The label of each (centered) transition is indicated in the title of each panel, in the format Branch(J,G). In the bottom left panel, transitions with G = 0, 1, 2, and 3 are superimposed. Continuum-subtracted observational data are shown in bla…

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Works this paper leans on

59 extracted references · 43 canonical work pages

  1. [1]

    S., Crofton, M

    Altman, R. S., Crofton, M. W., & Oka, T. 1984 a , , 81, 4255

    work page 1984

  2. [2]

    S., Crofton, M

    Altman, R. S., Crofton, M. W., & Oka, T. 1984 b , , 80, 3911

    work page 1984

  3. [3]

    M., Barb \'a , R., Aranda, R

    Apell \'a niz, J. M., Barb \'a , R., Aranda, R. F., et al. 2022, A&A, 657, A131

    work page 2022

  4. [4]

    2005, Physical review letters, 94, 073001

    Asvany, O., Giesen, T., Redlich, B., & Schlemmer, S. 2005, Physical review letters, 94, 073001

    work page 2005

  5. [5]

    Bally, J., O’Dell, C., & McCaughrean, M. J. 2000, Astron. J., 119, 2919

    work page 2000

  6. [6]

    2023, Journal of Molecular Spectroscopy, 398, 111840

    Bast, M., B \"o ing, J., Salomon, T., et al. 2023, Journal of Molecular Spectroscopy, 398, 111840

    work page 2023

  7. [7]

    Bernath, P. F. 2020, Journal of Quantitative Spectroscopy and Radiative Transfer, 240, 106687

    work page 2020

  8. [8]

    2022, , 134, 054301

    Bern \'e , O., Habart , \'E ., Peeters , E., et al. 2022, , 134, 054301

    2022

Show all 59 references
  1. [9]

    2024, Sci, 383, 988

    Bern \'e , O., Habart , E., Peeters , E., et al. 2024, Sci, 383, 988

    2024

  2. [10]

    2023, Nat, https://doi.org/10.1038/s41586-023-06307-x

    Bern \'e , O., Martin-Drumel , M.-A., Schroetter , I., & et al. 2023, Nat, https://doi.org/10.1038/s41586-023-06307-x

    2023 doi

  3. [11]

    o ker , T., Arribas , S., L \

    B \"o ker , T., Arribas , S., L \"u tzgendorf , N., et al. 2022, , 661, A82

    2022

  4. [12]

    A., Mizus, I

    Bowesman, C. A., Mizus, I. I., Zobov, N. F., et al. 2023, MNRAS, 519, 6333

    2023

  5. [13]

    S., Bernath, P

    Brooke, J. S., Bernath, P. F., Western, C. M., et al. 2016, Journal of Quantitative Spectroscopy and Radiative Transfer, 168, 142

    2016

  6. [14]

    B., Chen , N

    Changala , P. B., Chen , N. L., Le , H. L., et al. 2023, , 680, A19

    2023

  7. [15]

    W., Altman , R

    Crofton , M. W., Altman , R. S., Haese , N. N., & Oka , T. 1989, , 91, 5882

    1989

  8. [16]

    J., Davidson, D., & Hanson, R

    Dean, A. J., Davidson, D., & Hanson, R. 1991, The Journal of Physical Chemistry, 95, 183

    1991

  9. [17]

    L., Jusko , P., Schlemmer , S., & Asvany , O

    Dom \'e nech , J. L., Jusko , P., Schlemmer , S., & Asvany , O. 2018, , 857, 61

    2018

  10. [18]

    2019, Astron

    Foschino , S., Bern \'e , O., & Joblin , C. 2019, Astron. Astrophys., 632, A84

    2019

  11. [19]

    2010, A&A, 521, L16

    Gerin, M., De Luca, M., Goicoechea, J., et al. 2010, A&A, 521, L16

    2010

  12. [20]

    2025, A&A, 696, A100

    Goicoechea, J., Pety, J., Cuadrado, S., et al. 2025, A&A, 696, A100

    2025

  13. [21]

    R., Le Bourlot , J., Black , J

    Goicoechea , J. R., Le Bourlot , J., Black , J. H., et al. 2024, , 689, L4

    2024

  14. [22]

    R., Roncero , O., Roueff , E., et al

    Goicoechea , J. R., Roncero , O., Roueff , E., et al. 2025, Submitted to A&A [ [arXiv] 2506.05189 ]

    2025

  15. [23]

    2007, International Reviews in Physical Chemistry, 26, 29

    Gonz \'a lez-Lezana , T. 2007, International Reviews in Physical Chemistry, 26, 29

    2007

  16. [24]

    E., Rothman, L

    Gordon, I. E., Rothman, L. S., Hill, C., et al. 2017, Journal of quantitative spectroscopy and radiative transfer, 203, 3

    2017

  17. [25]

    N., Yurchenko, S

    Gorman, M. N., Yurchenko, S. N., & Tennyson, J. 2019, MNRAS, 490, 1652

    2019

  18. [26]

    Gruebele, M., Polak, M., & Saykally, R. J. 1987, , 87, 3347

    1987

  19. [27]

    J., Reiter , M., O'Dell , C

    Haworth , T. J., Reiter , M., O'Dell , C. R., et al. 2023, , 525, 4129

    2023

  20. [28]

    Hodges, J. N. & Bernath, P. F. 2017, ApJ, 840, 81

    2017

  21. [29]

    M., et al

    Jagod, M.-F., R \"o sslein, M., Gabrys, C. M., et al. 1992, , 97, 7111

    1992

  22. [30]

    J., & Pearson, J

    Lattanzi, V., Walters, A., Drouin, B. J., & Pearson, J. C. 2007, ApJ, 662, 771

    2007

  23. [31]

    2006, , 164, 506

    Le Petit , F., Nehm \'e , C., Le Bourlot , J., & Roueff , E. 2006, , 164, 506

    2006

  24. [32]

    E., Rothman, L

    Li, G., Gordon, I. E., Rothman, L. S., et al. 2015, ApJ Supplement Series, 216, 15

    2015

  25. [33]

    Lindsay, C. M. & McCall, B. J. 2001, Journal of Molecular Spectroscopy, 210, 60

    2001

  26. [34]

    N., & Oka, T

    Liu, D.-J., Haese, N. N., & Oka, T. 1985, , 82, 5368

    1985

  27. [35]

    2014, A&A, 571, A47

    Masseron, T., Plez, B., Van Eck, S., et al. 2014, A&A, 571, A47

    2014

  28. [36]

    R., & Stallard , T

    Miller , S., Tennyson , J., Geballe , T. R., & Stallard , T. 2020, Reviews of Modern Physics, 92, 035003

    2020

  29. [37]

    I., Alijah, A., Zobov, N

    Mizus, I. I., Alijah, A., Zobov, N. F., et al. 2017, MNRAS, 468, 1717

    2017

  30. [38]

    1980, , 45, 531

    Oka , T. 1980, , 45, 531

    1980

  31. [39]

    & Geballe , T

    Oka , T. & Geballe , T. R. 1990, , 351, L53

    1990

  32. [40]

    E., Johnson , S., et al

    Oka , T., Welty , D. E., Johnson , S., et al. 2013, , 773, 42

    2013

  33. [41]

    2024, A&A, 685, A74

    Peeters, E., Habart, E., Bern \'e , O., et al. 2024, A&A, 685, A74

    2024

  34. [42]

    2024, A&A, 689, L12

    Pereira-Santaella, M., Gonz \'a lez-Alfonso, E., Garc \' a-Bernete, I., et al. 2024, A&A, 689, L12

    2024

  35. [43]

    Perri, A. N. & McKemmish, L. K. 2024, MNRAS, 531, 3023

    2024

  36. [44]

    2012, A&A, 542, A69

    Pilleri, P., Montillaud, J., Berné, O., & Joblin, C. 2012, A&A, 542, A69

    2012

  37. [45]

    2024, Molecular Physics, 122, e2241567

    Schlemmer, S., Plaar, E., Gupta, D., et al. 2024, Molecular Physics, 122, e2241567

    2024

  38. [46]

    C., Asvany, O., Salomon, T., Thorwirth, S., & Schlemmer, S

    Schmid, P. C., Asvany, O., Salomon, T., Thorwirth, S., & Schlemmer, S. 2022, The Journal of Physical Chemistry A, 126, 8111

    2022

  39. [47]

    2025, Nat Astronomy, arXiv:2505.22314

    Schroetter , I., Bern \'e , O., Bron , E., et al. 2025, Nat Astronomy, arXiv:2505.22314

    2025 arXiv

  40. [48]

    M., Hodges , J

    Siller , B. M., Hodges , J. N., Perry , A. J., & McCall , B. J. 2013, Journal of Physical Chemistry A, 117, 10034

    2013

  41. [49]

    N., & Yachmenev, A

    Somogyi, W., Yurchenko, S. N., & Yachmenev, A. 2021, The Journal of Chemical Physics, 155

    2021

  42. [50]

    & Oka, T

    Tang, J. & Oka, T. 1999, Journal of molecular spectroscopy, 196, 120

    1999

  43. [51]

    N., Al-Refaie , A

    Tennyson , J., Yurchenko , S. N., Al-Refaie , A. F., et al. 2016, Journal of Molecular Spectroscopy, 327, 73

    2016

  44. [52]

    Western, C. M. 2017, J. Quant. Spectrosc. Radiat. Transf., 186, 221

    2017

  45. [53]

    G., Vallini, L., & Chevance, M

    Wolfire, M. G., Vallini, L., & Chevance, M. 2022, ARA&A, 60, 247

    2022

  46. [54]

    F., Hodges, J., & Masseron, T

    Yousefi, M., Bernath, P. F., Hodges, J., & Masseron, T. 2018, J. Quant, 474, 416

    2018

  47. [55]

    N., Sinden, F., Lodi, L., et al

    Yurchenko, S. N., Sinden, F., Lodi, L., et al. 2018, MNRAS, 473, 5324

    2018

  48. [56]

    2025, , 696, A99

    Zannese , M., Tabone , B., Habart , E., et al. 2025, , 696, A99

    2025

  49. [57]

    2024, Nat Astronomy, 8, 577

    Zannese , M., Tabone , B., Habart , E., et al. 2024, Nat Astronomy, 8, 577

    2024

  50. [58]

    , " * write output.state after.block = add.period write newline

    ENTRY address archiveprefix author booktitle chapter edition editor howpublished institution eprint journal key month note number organization pages publisher school series title type volume year label extra.label sort.label short.list INTEGERS output.state before.all mid.sent...

  51. [59]

    write newline

    " write newline "" before.all 'output.state := FUNCTION n.dashify 't := "" t empty not t #1 #1 substring "-" = t #1 #2 substring "--" = not "--" * t #2 global.max substring 't := t #1 #1 substring "-" = "-" * t #2 global.max substring 't := while if t #1 #1 substring * t #2 gl...

Pith tools

Reviewed August 7, 2026 · model on record in the stance chip above.