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REVIEW 2 major objections 6 minor 64 references

Tracking the Chemical Evolution of Hydrocarbons Through Carbon Grain Supply in Protoplanetary Disks

T0 review · 2 major / 6 minor · reviewed 2026-08-09 · deepseek-v4-flash

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Pith's one-line read The chemistry driver decides where carbon ends up in planet-forming disk gas.

desk verdict Useful hydrocarbon grid for JWST interpreters, but the headline water–C2H2 claim is confounded by the model setup. read the letter →

arxiv 2502.01765 v1 pith:L5EJWGN3 submitted 2025-02-03 astro-ph.EP

Eshan Raul , Felipe Alarcón , Edwin A. Bergin This is my paper · ORCID
classification astro-ph.EP
keywords astrochemistryprotoplanetarydiskshydrocarbonchemistryC/Oratiocosmic-rayionizationUVphotochemistryC2H2carbongraindestruction
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 asks where carbon goes when carbon-rich grains release their carbon into the hot inner gas of planet-forming disks, the region where terrestrial planets assemble. Using a grid of single-cell chemical models run at 400 K with gas density $10^8$ cm$^{-3}$, the authors vary the C/O ratio from 0.4 to 100 and compare two chemistry drivers: ionization by cosmic rays/X-rays versus ultraviolet light. They find the driver, not the C/O ratio, mostly sets the final carbon reservoirs: X-ray-driven chemistry parks carbon in CO and long-chain hydrocarbons (C5, C6, C8), while UV-driven chemistry parks it in atomic carbon and CO. They also find that C2H2, a key JWST tracer, is produced most efficiently at C/O = 1 and is boosted up to an order of magnitude by water, through the reaction $\mathrm{H_2O + C_2H_3^+ \rightarrow C_2H_2 + H_3O^+}$. The work matters because JWST now sees hydrocarbon-rich inner disks, and knowing which conditions produce those molecules constrains how refractory carbon is destroyed and whether forming planets inherit carbon-poor solids.

What carries the argument

The engine of the analysis is a single-cell chemical kinetics model built on the UMIST 2012 gas-phase network, with 536 species and 7349 reactions, integrated to 3 Myr at a fixed 400 K and $n_{\mathrm{H}} = 10^8$ cm$^{-3}$ with $10^{-2}$ cm grains. Carbon supply is injected by raising initial CH4, C, H2O, or CO abundances to set C/O ratios from 0.4 to 100, and the same grid is solved twice: once with only cosmic-ray/X-ray ionization ($\zeta = 5\times10^{-17}$ to $10^{-12}$ s$^{-1}$) and once with only UV photochemistry (0.007 to 45 $G_0$, i.e., multiples of the standard interstellar UV field). Dominant production and destruction pathways are extracted from the Jacobian of the network, which identifies which reaction carries the flux for each species at each time. The specific identity carrying the water dependence of C2H2 is the neutralization reaction $\mathrm{H_2O + C_2H_3^+ \rightarrow C_2H_2 + H_3O^+}$, which ties acetylene production to the presence of water rather than to free oxygen.

What would settle it

Rerun the same single-cell grid at $n_{\mathrm{H}} = 10^8$ cm$^{-3}$ and 400 K with the three-body and PAH-forming reactions that the paper cites in Section 4.3 included; the central claim fails if long-chain hydrocarbons no longer dominate the carbon budget in the X-ray limit, or if the order-of-magnitude water enhancement of C2H2 disappears. A complementary check: find a water-poor inner disk with strong persistent C2H2 emission, which the models say should not occur.

Watch

Extended reading notes

Core claim

The paper's central claim is that the carbon chemistry of inner disk gas is governed by what powers the chemistry, not simply by how much carbon is added. In the cosmic-ray/X-ray-driven limit, the excess carbon released from grains is funneled into CO and long-chain hydrocarbons C5, C6, C8, with C2H2, C2H4, C4H2, and C6H6 appearing transiently, while in the UV-driven limit the vast majority of carbon ends in atomic carbon and CO, with hydrocarbon enrichment short-lived. A second load-bearing claim is that C2H2 is optimally produced at C/O = 1, not at higher C/O, and that its abundance depends strongly, up to an order of magnitude, on initial water abundance via $\mathrm{H_2O + C_2H_3^+ \rightarrow C_2H_2 + H_3O^+}$. The authors further find that CH4 is a transient carbon donor that hands its carbon to CO, C2H2, and HCN, and that the choice of methane versus atomic carbon as the initial carrier of excess carbon hardly affects the final equilibrium, with both converging on similar timescales set by the ionization rate.

Load-bearing premise

The load-bearing assumption is that the UMIST 2012 gas-phase reaction set, without three-body reactions or polycyclic aromatic hydrocarbon formation, captures the dominant hydrocarbon chemistry at 400 K and $n_{\mathrm{H}} = 10^8$ cm$^{-3}$; the paper itself flags in Section 4.3 that adding three-body pathways can lead to vastly different reaction pathways.

Editorial extensions

If this is right

  • In X-ray/cosmic-ray-dominated inner disk gas, most excess carbon from grain destruction will be hidden in CO and in long-chain hydrocarbons (C5, C6, C8), so those species, not just C2H2, are the reservoirs to observe.
  • In UV-dominated gas, atomic carbon and CO hold the vast majority of the carbon; hydrocarbon molecules are transient, surviving only briefly or when carbon is continuously resupplied.
  • C2H2 is predicted to be brightest at C/O = 1 and in water-rich gas; boosting C/O beyond unity lowers its equilibrium abundance because carbon is parsed into chains in the X-ray case or into atomic carbon in the UV case.
  • Water presence enhances C2H2 by up to an order of magnitude through $\mathrm{H_2O + C_2H_3^+ \rightarrow C_2H_2 + H_3O^+}$, while water-poor gas shifts carbon toward CH3, CH4, and CH3+.
  • CH4 is a short-lived carbon donor in this chemistry, so its detection implies either recent or ongoing methane supply or a weakly ionizing environment, and whether the initial carrier is CH4 or atomic C barely changes the final equilibrium.

Reading between the lines

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

  • The authors do not pursue it, but their C/O = 1 optimum for C2H2 implies that high observed C2H2/CO2 ratios need not indicate extremely carbon-rich gas; they could mark moderate C/O combined with water-rich, X-ray-irradiated gas.
  • An untested consequence of the UV-limit result is that atomic carbon (C I) should be a bright reservoir in UV-driven inner disks, so C I line observations could directly test where carbon grain destruction products land.
  • Given the authors' flag that three-body reactions can change the pathways, rerunning this grid with the UMIST 2022 network or with three-body and PAH chemistry included would show whether the long-chain hydrocarbon sink is robust or an artifact of the 2012 network.
  • The convergent behavior of CH4 versus C as initial carriers suggests that in real disks the identity of the grain-destruction product matters mainly for early-time chemistry, not for the equilibrium composition; this could simplify how carbon-supply terms are parameterized in disk models.
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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

2 major / 6 minor

Summary. The paper presents single-cell gas-phase chemical models of the inner regions of protoplanetary disks, integrating the UMIST 2012 network with a stiff ODE solver. It explores how the carbon reservoir is partitioned as a function of C/O ratio, ionization rate, and the dominant ionization driver (X-ray/cosmic-ray versus UV). The authors report that X-ray-driven chemistry favors CO and long-chain hydrocarbons as carbon sinks, whereas UV-driven chemistry favors atomic carbon and CO, and they claim that C2H2 production is optimized at C/O=1 and enhanced by up to an order of magnitude by the initial water abundance through reactions such as H2O + C2H3+ -> C2H2 + H3O+. The paper is framed as a pathfinder for interpreting JWST hydrocarbon spectra of planet-forming disks.

Significance. The methodological core is conventional but sound: the chemical network is an externally published standard, the integration uses a public stiff solver, and the Jacobian-based pathway analysis is a clear and useful tool. The abundance maps for C2H2, CH4, CO2, and other hydrocarbons across ionization conditions and C/O ratios are a useful reference for interpreting mid-infrared disk observations. There is no circularity: no quantity is fitted to data, and the results are emergent outputs of the assumed network. The authors also deserve credit for explicitly flagging the omission of three-body reactions and PAH formation in Section 4.3. However, the two headline conclusions currently sit on fragile supports: the water-enhancement claim is confounded by simultaneous changes in the initial carbon and oxygen carriers, and the long-chain hydrocarbon carbon-sink claim has not been tested against a network that includes three-body chemistry. If the authors add the requested control runs and reconcile the model-count accounting, the paper will be a useful contribution to the field.

major comments (2)
  1. [§4.5, Fig. 5, Table 3, Reactions (8) and (24)] The central claim in the abstract and §4.5 that C2H2 production is enhanced by up to an order of magnitude by the initial water abundance is not supported by the model grid as presented. Figure 5 compares Models 2 and 6, but Table 3 changes three abundances at once: H2O is lowered from 1.5e-4 to 1e-8, CO is raised from 1e-14 to 1.5e-4, and CH4 is lowered from 1.5e-4 to 1e-14. The lower C2H2 could therefore be caused by carbon being locked in CO or by the absence of a reactive CH4 donor, rather than by the absence of H2O. In addition, the C/O sequence Models 2-5 is constructed by decreasing H2O while keeping CH4 and CO fixed, so the reported decline of C2H2 with increasing C/O is degenerate with decreasing initial water. Reaction (8), H2O + C2H3+ -> C2H2 + H3O+, makes a real water dependence plausible, but the model grid alone cannot separate water abundance from C/O or from the chemical state of the initial oxygen and carbon reservoirs. I request at least one control model in which only H2O is varied at fixed C/O, fixed CO, and fixed CH4, or an explicit sensitivity analysis that isolates the contribution of Reaction (8).
  2. [§4.3, §4.1, Fig. 4] The abstract's statement that CO and long-chain hydrocarbons act as carbon sinks in the cosmic/X-ray-driven limit is conditional on the UMIST 2012 gas-phase network. Section 4.3 itself notes that Kanwar et al. (2023) included three-body reactions and PAH formation, and that this 'can lead to vastly different reaction pathways than the simple ones we explore.' At the adopted n_H = 1e8 cm^-3 and T = 400 K, three-body association is expected to be competitive, so the carbon-sink partitioning could change qualitatively. Since Figure 4 and §4.1 use the long-chain species (C5, C6, C8) to contrast the X-ray and UV carbon-sink behavior, this omission is load-bearing. I recommend either adding three-body reactions and PAH formation in at least the fiducial X-ray and UV models, or explicitly framing the long-chain result as a two-body-only network result and qualifying the abstract accordingly.
minor comments (6)
  1. [Abstract, §1, Tables 2-3] The number of models is inconsistent: the abstract states 42 models, the introduction states 80 individual models, and Tables 2 and 3 imply 48 if every initial-condition model is run under every physical condition. Please reconcile the number and state the exact grid in one place.
  2. [Table 3, Model 6] The '...' notation in Table 3 is ambiguous for Model 6, because the row implies solar CH4 (1e-14) and solar CO (1.5e-4); please give explicit values and state which models correspond to the 'reduced water' case.
  3. [Fig. 5 caption] The Fig. 5 caption says 'with and without the presence of water (Models #2 vs. 6)', but these models also differ in CH4 and CO; rephrase to describe the two initial-condition prescriptions in Table 3 or add the requested control model.
  4. [§4.6] The phrase 'we proved one simulation' should read 'we ran one simulation'.
  5. [§2.2] The text says the evolution is run 'with logarithmic steps assuming a ratio of 1.1'; please define whether 1.1 is the ratio of successive time steps and state how many time steps were used.
  6. [§4.1] The claim that the UV-driven limit places the majority of carbon in atomic carbon and CO is based on Figure 4 for a single representative C/O ratio (Model #3); please state more explicitly how the conclusion extends across the full C/O grid, or add a supporting figure.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: conclusions emerge from an externally published chemical network with no fitted parameters; minor self-citations are contextual, not load-bearing.

full rationale

The paper's derivation chain is a forward chemical kinetics calculation using the externally published UMIST 2012 network (McElroy et al. 2013). The single-cell models integrate this network under stated initial abundances, temperatures, densities, ionization rates, and UV fields; no quantity is fitted to the outcomes it later reports, and no derived constant is reinserted as an input. The central claims—carbon partitioning into CO/long-chain hydrocarbons under X-ray/cosmic-ray drivers versus C/CO under UV, the transient donor role of CH4 and C, and the water sensitivity of C2H2—are emergent abundances from the ODE integration and carbon-budget accounting (e.g., Fig. 4). The C2H2–water connection is explicitly tied to a network reaction (H2O + C2H3+ -> C2H2 + H3O+, Eq. 8); while this makes the dependence mechanistically direct, it is not circular because the reaction rate is an independent external input and the model still computes the coupled outcome. Several works with overlapping authorship (Bergin, Duval, Bosman, Anderson, Li) are cited for context, physical parameters, and prior observational/theoretical support, but none is invoked as a uniqueness theorem or as the source of the present predictions, so self-citation is not load-bearing. One legitimate caveat, noted in the paper itself (§4.3), is that excluding three-body/PAH reactions may alter the chemistry; this is a completeness limitation, not circularity. A confounding feature (the C/O grid varies initial H2O, and the Model 2 vs 6 water comparison also changes CO and CH4) weakens the causal attribution of the C2H2 trend, but that is an experimental-design degeneracy, not circular reasoning by the criteria used here. Overall, the analysis is self-contained against an external benchmark network, and no prediction reduces to its inputs by construction.

Assumptions & free parameters 6 free parameters · 6 assumptions · 0 invented entities

The central claim rests on the fidelity of the UMIST 2012 network, the single-cell representation of the disk surface, and the choice of cosmic rays as an X-ray proxy. These are standard assumptions in astrochemistry but are not validated against observations here.

free parameters (6)
  • C/O ratio via initial CH4/C, H2O, CO abundances = 0.4, 1, 2, 6, 100
    Central exploratory axis, varied by hand to simulate different carbon supply scenarios; not fitted to data.
  • Ionization rate zeta = 1e-12, 1e-14, 1e-15, 5e-17 s^-1
    Grid parameter for cosmic-ray/X-ray-driven chemistry, chosen based on X-ray penetration estimates from Glassgold et al. (1997).
  • UV field strength = 45, 3.7, 0.3, 0.007 G0
    Grid parameter for UV-driven chemistry, chosen to cover strong to weak irradiation cases.
  • Initial water abundance = 2.25e-4, 1.5e-4, 7.5e-5, 2.5e-5, 1.5e-6, 1e-8
    Varied to set C/O and to test the dependence of hydrocarbon production on water; central to the C2H2 result.
  • Dust-to-gas ratio = 1e-3 (UV models), 1e-2 (X-ray models)
    Set separately for the two regimes to represent dust settling; affects grain surface reactions and charge balance.
  • Grain radius = 1e-2 cm
    Fixed to represent sub-mm grains that dominate dust mass in disk evolution models.
assumptions (6)
  • domain assumption UMIST 2012 reaction rate coefficients are accurate for the temperature (400 K) and density (1e8 cm^-3) regime explored.
    Section 2.1: the entire chemistry depends on this network; the paper notes a 2022 update exists but does not use it.
  • domain assumption Cosmic-ray ionization is a valid proxy for X-ray ionization of H2 in driving H3+ chemistry.
    Section 2.2: the authors justify this by the comparable production of H3+ and by observations of cosmic-ray attenuation.
  • domain assumption A single-cell, constant-temperature (400 K), constant-density model captures the chemistry of the emission layer.
    Section 2.2: the model ignores vertical structure, mixing, and thermal balance; the authors state this is a simplification.
  • ad hoc to paper Three-body reactions and PAH growth do not substantially alter the hydrocarbon pathways.
    Section 4.3 acknowledges Kanwar et al. (2023) include these and that they can lead to 'vastly different reaction pathways'; the paper assumes they are not needed.
  • domain assumption Photodesorption is negligible under the chosen high-temperature, high-extinction conditions.
    Section 2.2: the authors exclude photodesorption because the UV flux is small in shielded regions and temperatures are high.
  • standard math Numerical ODE integration with the QNDF solver reaches the correct chemical equilibrium by 3 Myr.
    Section 2.1: relies on the DifferentialEquations.jl solver to handle stiff kinetics; no convergence tests are shown.

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Pith. "Pith review of Tracking the Chemical Evolution of Hydrocarbons Through Carbon Grain Supply in Protoplanetary Disks." pith.science (2026). https://pith.science/paper/L5EJWGN3

@misc{pith2026250201765,
  author       = {Pith},
  title        = {Pith review of: Tracking the Chemical Evolution of Hydrocarbons Through Carbon Grain Supply in Protoplanetary Disks},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/L5EJWGN3}},
  note         = {Machine review of arXiv:2502.01765}
}
abstract

The gas present in planet-forming disks typically exhibits strong emission features of abundant carbon and oxygen molecular carriers. In some instances, protoplanetary disks show an elevated C/O ratio above interstellar values, which leads to a rich hydrocarbon chemistry evidenced in the mid-infrared spectra. The origin of this strengthened C/O ratio may stem from the release of less complex hydrocarbons from the chemical processing of carbonaceous grains. We have explored a set of 42 single-cell models in which we match the physical conditions to the inner regions of planet-forming disks, while varying the C/O ratio by exploring different levels of CH$_4$, C, H$_2$O, and CO to the gas-phase chemistry, which we evaluate in both the cosmic/X-ray and UV-driven limit. We find that the carbon-bearing species in our models exhibit high dependencies on the driver of the chemistry, where both CO and long chain hydrocarbons act as carbon sinks in the cosmic/X-ray-driven chemistry limit, while the vast majority ends up in atomic carbon and CO in the UV-driven limit. We also find moderate dependencies upon the C/O ratio, where this and the ionization rate/UV field determines the point of peak production of a species as well as its equilibrium abundance. We also find that the production of several hydrocarbons, specifically C$_2$H$_2$, is strongly dependent up to an order of magnitude on the initial water abundance. We lastly find that in the X-ray-driven limit, both CH$_4$ and C serve as highly transient donor species to the carbon chemistry.

Figures

Figures reproduced from arXiv: 2502.01765 by the authors.

Figure 1
Figure 1. Omnibus plots of C2H2, CH4, H2O, CO, CO2, and C showing the relative abundance of these species at every chemical condition for a number density of 108 cm−3 in the X-ray dominated case, sorted by initial C/O ratio. The solid lines represent the abundances of our simulations using our fiducial ionization rate ζ15 (ζ = 10−15s −1 ), while the faded lines portray our other modeled rates (ζ12, ζ14, and ζ17). We find that… view at source ↗
Figure 2
Figure 2. Omnibus plots of C2H2, CH4, H2O, CO, CO2, and C showing the relative abundance of these species at every chemical condition for a number density of 108 cm−3 in the UV dominated case, sorted by initial C/O ratio, done in the same manner as [PITH_FULL_IMAGE:figures/full_fig_p008_2.png] view at source ↗
Figure 3
Figure 3. Heat map of key hydrocarbons abundance at 3 × 106 years for different C/O ratios and physical conditions in both the X-ray and UV-dominated chemistry regimes. We find that in our high UV field models (UV1 and UV2), virtually no chemistry occurs whatsoever, as can also be seen by the lack of non-fiducial models in [PITH_FULL_IMAGE:figures/full_fig_p011_3.png] view at source ↗
Figures from the paper (5 more)
Figure 4
Figure 4. Figure 4: 4-panel individual species plot of the amount of carbon in each carbon-bearing species for both the UV and the X-ray case. All panels are displayed at our fiducial ζ15 (ζ = 10−15s −1 ) ionization rate at a C/O = 2 (Model #3). This plot changes as C/O increases (not sho…
Figure 5
Figure 5. Figure 5: Abundance over time plot showing the production of several hydrocarbons with and without the presence of water (Models #2 vs. 6). This model is evaluated in the X-ray dominated case at our ζ14 (ζ = 10−14s −1 ) ionization rate. demonstrating that C2H2 is even more stabl…
Figure 6
Figure 6. Figure 6: Abundance over time plot showing the production of several hydrocarbons with CH4 vs. C as an initial carrier. This model is evaluated in the X-ray dominated case at our fiducial ζ15 (ζ = 10−15s −1 ) ionization rate at a C/O = 2 (Model #3). We have also found that the i…
Figure 7
Figure 7. Figure 7: Omnibus plots of HCN, C2H4, C4H2, and C6H6 C showing the relative abundance of these species in the X-ray dominated case, sorted by initial C/O ratio, done in the same manner as [PITH_FULL_IMAGE:figures/full_fig_p016_7.png]
Figure 8
Figure 8. Figure 8: Omnibus plots of HCN, C2H4, C4H2, and C6H6 showing the relative abundance of these species in the UV dominated case, sorted by initial C/O ratio, done in the same manner as [PITH_FULL_IMAGE:figures/full_fig_p017_8.png]

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Works this paper leans on

64 extracted references · 12 canonical work pages

  1. [1]

    R., Cernicharo, J., Faure, A., & Roueff, E

    Ag´ undez, M., Goicoechea, J. R., Cernicharo, J., Faure, A., & Roueff, E. 2010, ApJ, 713, 662, doi: 10.1088/0004-637X/713/1/662

    work page doi:10.1088/0004-637x/713/1/662 2010

  2. [2]

    1999, A&A, 351, 233

    Aikawa, Y., & Herbst, E. 1999, A&A, 351, 233

    1999

  3. [3]

    2021, ApJS, 257, 13, doi: 10.3847/1538-4365/ac143c Alarc´ on, F., Teague, R., Zhang, K., Bergin, E

    Aikawa, Y., Cataldi, G., Yamato, Y., et al. 2021, ApJS, 257, 13, doi: 10.3847/1538-4365/ac143c Alarc´ on, F., Teague, R., Zhang, K., Bergin, E. A., &

    doi:10.3847/1538-4365/ac143c 2021

  4. [4]

    2020, ApJ, 905, 68, doi: 10.3847/1538-4357/abc1d6 Alarc´ on, F., Bosman, A

    Barraza-Alfaro, M. 2020, ApJ, 905, 68, doi: 10.3847/1538-4357/abc1d6 Alarc´ on, F., Bosman, A. D., Bergin, E. A., et al. 2021, ApJS, 257, 8, doi: 10.3847/1538-4365/ac22ae

    doi:10.3847/1538-4357/abc1d6 2020

  5. [5]

    E., Bergin, E

    Anderson, D. E., Bergin, E. A., Blake, G. A., et al. 2017, ApJ, 845, 13, doi: 10.3847/1538-4357/aa7da1

    doi:10.3847/1538-4357/aa7da1 2017

  6. [6]

    E., Blake, G

    Anderson, D. E., Blake, G. A., Cleeves, L. I., et al. 2021, ApJ, 909, 55, doi: 10.3847/1538-4357/abd9c1

    doi:10.3847/1538-4357/abd9c1 2021

  7. [7]

    M., Kamp, I., Henning, T., et al

    Arabhavi, A. M., Kamp, I., Henning, T., et al. 2024, Science, 384, 1086, doi: 10.1126/science.adi8147

    doi:10.1126/science.adi8147 2024

  8. [8]

    A., Aikawa, Y., Blake, G

    Bergin, E. A., Aikawa, Y., Blake, G. A., & van Dishoeck, E. F. 2007, in Protostars and Planets V, ed. B. Reipurth, D. Jewitt, & K. Keil, 751, doi: 10.48550/arXiv.astro-ph/0603358

    arXiv doi:10.48550/arxiv.astro-ph/0603358 2007

Show all 64 references
  1. [9]

    A., Blake, G

    Bergin, E. A., Blake, G. A., Ciesla, F., Hirschmann, M. M., & Li, J. 2015, Proceedings of the National Academy of Science, 112, 8965, doi: 10.1073/pnas.1500954112

    2015 doi

  2. [10]

    A., Melnick, G

    Bergin, E. A., Melnick, G. J., & Neufeld, D. A. 1998, ApJ, 499, 777, doi: 10.1086/305656 Bern´ e, O., Martin-Drumel, M.-A., Schroetter, I., et al. 2023, Nature, doi: 10.1038/s41586-023-06307-x

    1998 doi

  3. [11]

    J., & Bergin, E

    Bethell, T. J., & Bergin, E. A. 2011, ApJ, 740, 7, doi: 10.1088/0004-637X/740/1/7

    2011 doi

  4. [12]

    2023, MNRAS, 520, 2055, doi: 10.1093/mnras/stad182

    Binkert, F., & Birnstiel, T. 2023, MNRAS, 520, 2055, doi: 10.1093/mnras/stad182

    2023 doi

  5. [13]

    2016, SSRv, 205, 41, doi: 10.1007/s11214-016-0256-1

    Birnstiel, T., Fang, M., & Johansen, A. 2016, SSRv, 205, 41, doi: 10.1007/s11214-016-0256-1

    2016 doi

  6. [14]

    D., Bergin, E

    Bosman, A. D., Bergin, E. A., Calahan, J., & Duval, S. E. 2022, ApJL, 930, L26, doi: 10.3847/2041-8213/ac66ce

    2022 doi

  7. [15]

    2023, MNRAS, 522, 3378, doi: 10.1093/mnras/stad1159

    Broome, M., Kama, M., Booth, R., & Shorttle, O. 2023, MNRAS, 522, 3378, doi: 10.1093/mnras/stad1159

    2023 doi

  8. [16]

    S., & Najita, J

    Carr, J. S., & Najita, J. R. 2008, Science, 319, 1504, doi: 10.1126/science.1153807

    2008 doi

  9. [17]

    2012, A&A, 538, A128, doi: 10.1051/0004-6361/201117409

    Chaabouni, H., Bergeron, H., Baouche, S., et al. 2012, A&A, 538, A128, doi: 10.1051/0004-6361/201117409

    2012 doi

  10. [18]

    2013, ApJ, 770, 78, doi: 10.1088/0004-637X/770/1/78

    Ricca, A. 2013, ApJ, 770, 78, doi: 10.1088/0004-637X/770/1/78

    2013 doi

  11. [19]

    I., Bergin, E

    Cleeves, L. I., Bergin, E. A., Qi, C., Adams, F. C., & ¨Oberg, K. I. 2015, ApJ, 799, 204, doi: 10.1088/0004-637X/799/2/204

    2015 doi

  12. [20]

    Du, F., & Bergin, E. A. 2014, ApJ, 792, 2, doi: 10.1088/0004-637X/792/1/2

    2014 doi

  13. [21]

    E., Bosman, A

    Duval, S. E., Bosman, A. D., & Bergin, E. A. 2022, ApJL, 934, L25, doi: 10.3847/2041-8213/ac822b

    2022 doi

  14. [22]

    2018, A&A, 612, A104, doi: 10.1051/0004-6361/201731390

    Ovelar, M. 2018, A&A, 612, A104, doi: 10.1051/0004-6361/201731390

    2018 doi

  15. [23]

    Fomenkova, M. N. 1999, SSRv, 90, 109, doi: 10.1023/A:1005237828783

    1999 doi

  16. [24]

    Gail, H. P. 2002, A&A, 390, 253, doi: 10.1051/0004-6361:20020614

    2002 doi

  17. [25]

    2017, A&A, 606, A16, doi: 10.1051/0004-6361/201730480

    Gail, H.-P., & Trieloff, M. 2017, A&A, 606, A16, doi: 10.1051/0004-6361/201730480

    2017 doi

  18. [26]

    T., Widicus Weaver, S

    Garrod, R. T., Widicus Weaver, S. L., & Herbst, E. 2008, ApJ, 682, 283, doi: 10.1086/588035

    2008 doi

  19. [27]

    F., Grant, S

    Gasman, D., van Dishoeck, E. F., Grant, S. L., et al. 2023, arXiv e-prints, arXiv:2307.09301, doi: 10.48550/arXiv.2307.09301

    2023 doi arXiv

  20. [28]

    E., Najita, J., & Igea, J

    Glassgold, A. E., Najita, J., & Igea, J. 1997, ApJ, 480, 344, doi: 10.1086/303952

    1997 doi

  21. [29]

    2011, ApJ, 735, 90, doi: 10.1088/0004-637X/735/2/90

    Gorti, U., Hollenbach, D., Najita, J., & Pascucci, I. 2011, ApJ, 735, 90, doi: 10.1088/0004-637X/735/2/90

    2011 doi

  22. [30]

    L., van Dishoeck, E

    Grant, S. L., van Dishoeck, E. F., Tabone, B., et al. 2023, ApJL, 947, L6, doi: 10.3847/2041-8213/acc44b

    2023 doi

  23. [31]

    I., Herbst, E., & Leung, C

    Hasegawa, T. I., Herbst, E., & Leung, C. M. 1992, ApJS, 82, 167, doi: 10.1086/191713

    1992 doi

  24. [32]

    2021, Frontiers in Astronomy and Space Sciences, 8, 207, doi: 10.3389/fspas.2021.776942

    Herbst, E. 2021, Frontiers in Astronomy and Space Sciences, 8, 207, doi: 10.3389/fspas.2021.776942

    2021

  25. [33]

    P., Fanciullo, L., K¨ ohler, M., et al

    Jones, A. P., Fanciullo, L., K¨ ohler, M., et al. 2013, A&A, 558, A62, doi: 10.1051/0004-6361/201321686

    2013 doi

  26. [34]

    F., & Hogerheijde, M

    Kamp, I., Tilling, I., Woitke, P., Thi, W. F., & Hogerheijde, M. 2010, A&A, 510, A18, doi: 10.1051/0004-6361/200913076

    2010 doi

  27. [35]

    M., et al

    Kamp, I., Henning, T., Arabhavi, A. M., et al. 2023, Faraday Discussions, 245, 112, doi: 10.1039/D3FD00013C

    2023 doi

  28. [36]

    2023, arXiv e-prints, arXiv:2310.04505, doi: 10.48550/arXiv.2310.04505

    Kanwar, J., Kamp, I., Woitke, P., et al. 2023, arXiv e-prints, arXiv:2310.04505, doi: 10.48550/arXiv.2310.04505

    2023 doi arXiv

  29. [37]

    2024, A&A, in press, doi: 10.48550/arXiv.2407.14362

    Kanwar, J., Kamp, I., Jang, H., et al. 2024, A&A, in press, doi: 10.48550/arXiv.2407.14362

    2024 doi arXiv

  30. [38]

    J., & Neufeld, D

    Kaufman, M. J., & Neufeld, D. A. 1996, ApJ, 456, 611, doi: 10.1086/176683

    1996 doi

  31. [39]

    W., & Dominik, C

    Klarmann, L., Ormel, C. W., & Dominik, C. 2018, A&A, 618, L1, doi: 10.1051/0004-6361/201833719

    2018 doi

  32. [40]

    A., & Nomura, H

    Lee, J.-E., Bergin, E. A., & Nomura, H. 2010, ApJL, 710, L21, doi: 10.1088/2041-8205/710/1/L21

    2010 doi

  33. [41]

    Hirschmann, M. M. 2021, Science Advances, 7, eabd3632, doi: 10.1126/sciadv.abd3632 19

    2021 doi

  34. [42]

    2023, A&A, 677, L7, doi: 10.1051/0004-6361/202347169

    Mah, J., Bitsch, B., Pascucci, I., & Henning, T. 2023, A&A, 677, L7, doi: 10.1051/0004-6361/202347169

    2023 doi

  35. [43]

    J., et al

    McElroy, D., Walsh, C., Markwick, A. J., et al. 2013, A&A, 550, A36, doi: 10.1051/0004-6361/201220465

    2013 doi

  36. [44]

    M., Blake, G

    Meijerink, R., Pontoppidan, K. M., Blake, G. A., Poelman, D. R., & Dullemond, C. P. 2009, ApJ, 704, 1471, doi: 10.1088/0004-637X/704/2/1471

    2009 doi

  37. [45]

    J., Walsh, C., Van de Sande, M., & Markwick, A

    Millar, T. J., Walsh, C., Van de Sande, M., & Markwick, A. J. 2024, A&A, 682, A109, doi: 10.1051/0004-6361/202346908

    2024 doi

  38. [46]

    2015, ApJ, 809, 120, doi: 10.1088/0004-637X/809/2/120

    Mishra, A., & Li, A. 2015, ApJ, 809, 120, doi: 10.1088/0004-637X/809/2/120

    2015 doi

  39. [47]

    R., ´Ad´ amkovics, M., & Glassgold, A

    Najita, J. R., ´Ad´ amkovics, M., & Glassgold, A. E. 2011, ApJ, 743, 147, doi: 10.1088/0004-637X/743/2/147

    2011 doi

  40. [48]

    F., & Przybilla, N

    Nieva, M. F., & Przybilla, N. 2012, A&A, 539, A143, doi: 10.1051/0004-6361/201118158

    2012 doi

  41. [49]

    Millar, T. J. 2007, ApJ, 661, 334, doi: 10.1086/513419

    2007 doi

  42. [50]

    Nomura, H., & Millar, T. J. 2005, A&A, 438, 923, doi: 10.1051/0004-6361:20052809

    2005 doi

  43. [51]

    2009, ApJ, 696, 143, doi: 10.1088/0004-637X/696/1/143

    Pascucci, I., Apai, D., Luhman, K., et al. 2009, ApJ, 696, 143, doi: 10.1088/0004-637X/696/1/143

    2009 doi

  44. [52]

    S., & Bruderer, S

    Pascucci, I., Herczeg, G., Carr, J. S., & Bruderer, S. 2013, ApJ, 779, 178, doi: 10.1088/0004-637X/779/2/178

    2013 doi

  45. [53]

    M., Salyk, C., Blake, G

    Pontoppidan, K. M., Salyk, C., Blake, G. A., et al. 2010, ApJ, 720, 887, doi: 10.1088/0004-637X/720/1/887

    2010 doi

  46. [54]

    2005, ApJS, 160, 401, doi: 10.1086/432891

    Preibisch, T., Kim, Y.-C., Favata, F., et al. 2005, ApJS, 160, 401, doi: 10.1086/432891

    2005 doi

  47. [55]

    2017, The Journal of Open Research Software, 5, doi: 10.5334/jors.151

    Rackauckas, C., & Nie, Q. 2017, The Journal of Open Research Software, 5, doi: 10.5334/jors.151

    2017 doi

  48. [56]

    C., Bik, A., Cuijpers, L., et al

    Ramirez-Tannus, M. C., Bik, A., Cuijpers, L., et al. 2023, arXiv e-prints, arXiv:2310.11074, doi: 10.48550/arXiv.2310.11074

    2023 doi arXiv

  49. [57]

    2019, MNRAS, 489, 594, doi: 10.1093/mnras/stz2086

    Rubin, M., Altwegg, K., Balsiger, H., et al. 2019, MNRAS, 489, 594, doi: 10.1093/mnras/stz2086

    2019 doi

  50. [58]

    M., Blake, G

    Salyk, C., Pontoppidan, K. M., Blake, G. A., Najita, J. R., & Carr, J. S. 2011, ApJ, 731, 130, doi: 10.1088/0004-637X/731/2/130

    2011 doi

  51. [59]

    A., Cleeves, L

    Seifert, R. A., Cleeves, L. I., Adams, F. C., & Li, Z.-Y. 2021, ApJ, 912, 136, doi: 10.3847/1538-4357/abf09a

    2021 doi

  52. [60]

    F., et al

    Tabone, B., Bettoni, G., van Dishoeck, E. F., et al. 2023, Nature Astronomy, 7, 805, doi: 10.1038/s41550-023-01965-3 van der Marel, N., Williams, J. P., & Bruderer, S. 2018, ApJL, 867, L14, doi: 10.3847/2041-8213/aae88e van Dishoeck, E. F., Grant, S., Tabone, B., et al. 2023, ...

    2023 doi

  53. [61]

    F., & Graff, M

    Wagner, A. F., & Graff, M. M. 1987, ApJ, 317, 423, doi: 10.1086/165287

    1987 doi

  54. [62]

    2019, ApJ, 870, 129, doi: 10.3847/1538-4357/aaf390

    Wei, C.-E., Nomura, H., Lee, J.-E., et al. 2019, ApJ, 870, 129, doi: 10.3847/1538-4357/aaf390

    2019 doi

  55. [63]

    F., Arabhavi, A

    Woitke, P., Thi, W. F., Arabhavi, A. M., et al. 2024, A&A, 683, A219, doi: 10.1051/0004-6361/202347730

    2024 doi

  56. [64]

    Millar, T. J. 2007, A&A, 466, 1197, doi: 10.1051/0004-6361:20064981

    2007 doi

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