Pith. sign in

REVIEW 4 major objections 6 minor 89 references

AB Aur's planet-forming disk is azimuthally chemically differentiated: SO peaks in the north at the streamer impact site, C2H in the south, which the paper attributes to a gas-phase C/O gradient jointly maintained by late infall and planet

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · deepseek-v4-flash

2026-08-01 14:39 UTC pith:GNY4M3FL

load-bearing objection Resolved SO–C2H anti-correlation in AB Aur is a real observational result; the azimuthal C/O-gradient interpretation is plausible but conditional on a chemical model the authors admit cannot fit all three tracers. the 4 major comments →

arxiv 2607.18683 v1 pith:GNY4M3FL submitted 2026-07-21 astro-ph.EP

Azimuthal molecular variations in the AB Aur planet-forming disk

classification astro-ph.EP
keywords protoplanetary disksdisk chemistryAB Aurazimuthal chemical asymmetrygas-phase C/O ratiolate infallstreamersmolecular line survey
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

Using new 1.2 mm interferometric observations, this paper tries to establish that the AB Aur protoplanetary disk is not chemically uniform around its ring. It finds sulfur monoxide (SO) emission concentrated in the northern sector at the inferred impact site of a late-infall streamer, while the ethynyl radical C2H peaks on the opposite southern side and carbon monosulfide (CS) remains an almost symmetric ring. Multi-transition analysis shows the SO enhancement is a real abundance and temperature contrast, not just an excitation effect. Comparison with gas-grain chemical models favors an azimuthal gradient in effective gas-phase C/O: lower (more oxygen-rich) in the north, higher (carbon-rich) in the south, with the global C/O at or above unity. If right, the result shows that environmental accretion and planet formation can jointly create chemical heterogeneity that affects the compositions of forming planets.

Core claim

The central discovery is the chemically selective azimuthal differentiation of the AB Aur disk at roughly 150–220 au: all detected SO transitions peak in the north, spatially coincident with the streamer–disk interaction region; C2H peaks on the opposite southern side; CS forms a nearly axisymmetric ring; HCN and HCO+ peak near a dust continuum overdensity. The paper further claims that this pattern cannot be fully explained by excitation or temperature differences, and that chemical modeling points to a relative difference in effective gas-phase C/O between sectors—higher in the C2H-bright south, with a global C/O at or above unity. It proposes two non-exclusive causes: infall-induced heati

What carries the argument

The analytical engine is a set of molecular line diagnostics applied to a 1.2 mm spectral survey: multi-transition LTE rotational diagram fits for SO and CS to separate column density from excitation; a stacked C2H hyperfine map; an HCO+/H13CO+ ratio to constrain optical depth; and a grid of time-dependent gas-grain chemical models varying elemental C/O. The load-bearing identity is the tracer–C/O mapping—SO favored at low C/O, C2H favored at high C/O, CS nearly insensitive—which converts the observed SO–C2H anti-correlation into an inferred azimuthal C/O gradient.

Load-bearing premise

The inference from chemical asymmetries to an azimuthal C/O gradient rests on the assumption that current sulfur chemistry networks map SO to low C/O, C2H to high C/O, and CS to insensitivity correctly in AB Aur's outer disk; the paper itself concedes that no single C/O ratio can simultaneously reproduce the observed CS, SO, and C2H abundances, so if that tracer–C/O mapping is warped by missing sulfur chemistry or by the fixed 40 K temperature used for comparison, the inferre

What would settle it

Settle it with a calculation: run a chemical network that includes revised sulfur depletion or shock chemistry to see whether a single disk-wide C/O can already produce the observed SO and C2H contrasts; if so, the azimuthal C/O gradient is not needed. Observationally, detect a second C2H transition to break the excitation degeneracy—if C2H column densities become symmetric once temperature is modeled properly, the southern C-rich reading fails. Also image SO2 and OCS: if they do not peak near the northern streamer impact site, the infall-desorption scenario for the O-rich sector is contradict

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • AB Aur's outer molecular ring is chemically heterogeneous: SO and C2H are anti-correlated at ~200 au while CS stays symmetric.
  • The global gas-phase C/O in AB Aur's outer disk is near or above unity rather than the solar/ISM value of ~0.4.
  • The northern sector is O-rich and the southern sector C-rich in effective gas-phase composition, implying that planets forming in different sectors can inherit different carbon-to-oxygen ratios.
  • HCO+ is optically thick across the molecular ring, so its azimuthal brightness maps excitation temperature and the tau~1 surface, not column density.
  • The elevated HCO+/H13CO+ ratio inside the cavity indicates an enhanced 12C/13C ratio from isotope-selective photodissociation, so giant planets with sub-ISM 12C/13C likely accreted their atmospheres from the outer disk.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If late infall episodically resets local C/O toward ISM-like values, disk-averaged C/O measurements in similar disks could hide strong azimuthal variation; averaging O-rich and C-rich sectors might produce a misleadingly solar value.
  • The SO/C2H anti-correlation could serve as a two-color azimuthal C/O diagnostic; applying it to other disks with known streamers would test whether infall impacts generically create SO-bright, O-rich sectors.
  • Because the sulfur network cannot fit all three species simultaneously, current models likely miss shock or organosulfur pathways; incorporating them might shift the inferred C/O values, so the quantitative gradient should be treated as provisional.
  • A direct test would be deep searches for SO2, OCS, warm H2CO, and CH3OH in the north and CN or c-C3H2 in the south; their spatial coincidence with the respective sectors would support the two-mechanism picture.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

4 major / 6 minor

Summary. The paper presents new NOEMA 1.2 mm observations of AB Aur and analyses maps of CS, SO, C2H, HCN, HCO+, and H13CO+. The central observational result is a chemically selective azimuthal asymmetry: SO is enhanced in the northern sector near the inferred streamer–disk interaction region, C2H peaks on the opposite southern side, CS forms a nearly axisymmetric ring, and HCN/HCO+ are brightest near the dust continuum overdensity. The authors perform LTE rotational-diagram analyses for SO and CS, derive C2H column densities under assumed rotational temperatures, and compare the derived columns with ALCHEMIC gas-grain chemical models over a grid of C/O ratios. They conclude that the data favor gas-phase C/O near or above unity, with a higher effective C/O in the C2H-bright sector, and discuss two scenarios: infall-induced O-rich chemistry at the streamer impact site and planet-driven carbon enhancement on the opposite side. The paper includes extensive appendices with continuum maps, channel maps, and archival data.

Significance. If the azimuthal C/O interpretation is accepted, this would be an important step: it would demonstrate that infall and planet formation jointly produce resolvable chemical inhomogeneity in a single disk, with consequences for planet atmospheric composition. The strictly observational message is strong and valuable independent of the chemical modeling: multiple SO transitions, four C2H hyperfine components stacked in visibility, and an independent CS control all point to a robust spatial anti-correlation. The authors also make sensible methodological choices in moment extraction and provide the channel-map material needed to judge the maps. However, the quantitative bridge from the observed anti-correlation to the headline C/O gradient is currently built on a chemical model that the authors themselves state cannot reproduce the three key molecules simultaneously, and it is sensitive to a fixed T_rot assumption and to a factor 2–3 SO flux discrepancy with previously published work. The paper’s cautious wording in Section 4.2 is not carried through to the abstract and summary, which assert the C/O inference more strongly than the model validation supports.

major comments (4)
  1. [§4.2, Figs. 11–12] The central interpretive claim, C/O ≥ 1 with a higher effective C/O in the C2H-bright sector, is not supported by a model that simultaneously fits the data. The text states that the models 'cannot simultaneously reproduce the abundances of CS, SO, and C2H ... with a single C/O ratio', that CS prefers C/O slightly below unity, SO slightly above unity, and C2H requires C/O ≫ 1, and that the sulfur network is likely incomplete. Yet the abstract and Section 6 conclude that the comparison favors C/O near or above unity. Because the SO–C2H anti-correlation is the basis for the sector C/O difference, the conclusion depends on the reliability of the tracer–C/O mapping. The authors should either provide sensitivity tests showing the mapping is robust against the known missing sulfur chemistry (e.g., varying sulfur depletion, adding simple organosulfide pathways, changing the gas-to-dust ratio), o
  2. [§3.2.2, §4.2, Eq. (3), Fig. 8] The model comparison for C2H is made at a fixed T_rot = 40 K, but the C2H column density depends sensitively on the assumed excitation. Eq. (3) and Fig. 8 show that N(C2H) varies by roughly a factor 2–3 over the plausible range 15–160 K, with the minimum near E_u = 25 K. Since C2H is the molecule that drives the C/O ≫ 1 conclusion, the inferred C/O could shift by a full grid step if the emitting layer is warmer or cooler than 40 K. The authors should show the C2H model comparison over the allowed T_rot range, or better, compute model line intensities at the model gas temperature rather than quoting a single fixed-temperature column. This is a load-bearing point because the abstract’s claim of C/O near or above unity rests substantially on the C2H comparison.
  3. [§3.2.1] The SO rotational-temperature and column-density results, which anchor the 'warm, O-rich north' interpretation, are derived from fluxes that the paper reports as a factor 2–3 higher than Dutrey et al. (2024) for the same transitions. The authors state that the absolute flux calibration uncertainty is ~10% and that investigating the discrepancy is beyond their scope. This discrepancy is not a minor calibration detail: it moves the disk-averaged SO T_rot from ~20 K to 37 K and directly affects the NE/SW temperature and column-density contrast used to infer the sector C/O difference. I am not asking for a full re-analysis, but the manuscript should at least (i) quantify how the derived T_rot and N_SO profiles change if the Dutrey fluxes are adopted, and (ii) explicitly state that the quantitative sector C/O inference is uncertain at this level. The morphological anti-correlation is unaffect
  4. [§5.1.1, §5.1.2] The two physical scenarios (infall-driven O-rich chemistry in the north, planet-driven carbon enhancement in the south) are presented as the likely origin of the C/O gradient, but neither scenario is modeled with local conditions; the case is made by qualitative mapping and by spatial coincidence with previously reported features. Given that the chemical network already fails to reproduce CS, SO, and C2H simultaneously in the axisymmetric model, the sector-specific scenarios would benefit from a concrete test: for example, a local C/O perturbation, a temperature perturbation, or an S-ice desorption prescription applied to the same grid, with predicted SO/C2H/CS maps or visibilities. The current text lists testable predictions, which is good, but the connection between the observed asymmetry and a specific physical mechanism remains model-unsupported. This should be acknowledged in the ab
minor comments (6)
  1. [§3.1] Typo: 'a small enhancement in appears in the quadratic fit' should read 'a small enhancement appears in ...'. Also, 'the only specie' should be 'the only species'.
  2. [§4.2, Fig. 11] Fig. 11 caption says 'chemical productions'; this should be 'chemical model predictions' or 'model abundances'.
  3. [§4] The sentence 'Together, these processes redistributes carbon- and oxygen-bearing volatiles' has a subject-verb agreement error: 'redistribute'.
  4. [§3.2.1] The statement 'we refrain from drawing conclusions regarding the differences with Dutrey et al. (2024)' is contradicted a little by the immediately preceding discussion; it would be helpful to state clearly which of the paper’s quantitative results would survive if the lower fluxes were used.
  5. [Table D.1] The footnote for the CS 7–6 flux is verbose; a concise statement of the integration method and the comparison value would be easier to read.
  6. [Fig. 3/4 captions] The notation 'r=0.5' is used for the robust parameter in the caption text but is not defined there; since the main text uses 'Briggs robust parameter', the caption should be unambiguous.

Circularity Check

0 steps flagged

No significant circularity: the SO–C2H anti-correlation and the C/O-gradient interpretation rest on independent observations and external chemical-mapping support; the model limitations are caveats, not circular steps.

full rationale

The derivation chain is not circular. The central observational result—SO enhanced in the north, C2H in the south, CS nearly axisymmetric—is measured directly from the NOEMA cubes and moment maps (Sect. 3.1), with no dependence on the chemical model. The C/O interpretation (Sect. 4) compares the observed column densities to a precomputed ALCHEMIC/KIDA grid in which the elemental C/O is varied independently; the tracer–C/O mapping is not fitted to the AB Aur azimuthal data and is independently supported by external studies cited by the paper (Le Gal et al. 2021; Bosman et al. 2021a; Keyte et al. 2023). The disk structure and ALCHEMIC code come from prior work by coauthors (Semenov; Rivière-Marichalar), but that is tool provenance, not an input that is renamed as a prediction. The paper explicitly concedes in Sect. 4.2 that “the observationally derived abundances and predictions from contemporary chemical models cannot simultaneously reproduce the abundances of CS, SO, and C2H ... with a single C/O ratio” and that sulfur chemistry is likely missing; this is an openly stated correctness/robustness limitation, not a circular reduction. The proposed interpretations and “testable predictions” (warm H2CO, CH3OH, SO2 in the north; CN, c-C3H2 and planet signatures in the south) are additional observational expectations, not restatements of the data used to infer C/O. No equation reduces to another by construction, and no fitted parameter is relabeled as a prediction. Minor self-citations are present but are not load-bearing.

Axiom & Free-Parameter Ledger

10 free parameters · 6 axioms · 0 invented entities

The directly imaged SO/C2H anti-correlation does not depend on the model inputs. The quantitative C/O layer rests on a parametric 1+1D disk structure from the authors' previous modeling (Rivière-Marichalar et al. 2020, 2022, 2026), on the ALCHEMIC network (Semenov et al. 2010, 2018), and on assumed temperatures (T_rot = 40 K for model comparison; 100/60 K for the C2H excitation test). No new physical entities are introduced; the streamer and protoplanet candidates are taken from prior literature.

free parameters (10)
  • T_mid,0 = 42 K
    Midplane temperature normalization in Eq. (6), taken from Rivière-Marichalar et al. (2020) fit; sets freeze-out/desorption and thermal structure in the chemical model.
  • T_atm,0 = 70 K
    Atmosphere temperature normalization in Eq. (7), same provenance.
  • Sigma_0 = 0.5 g cm^-2
    Surface-density normalization at R0 in Eq. (10); controls total gas column densities in the model grid.
  • R0 = 98 au
    Characteristic radius of the disk model power laws.
  • gas-to-dust mass ratio = 40
    Adopted fiducial in Section 4.1; paper notes observational estimates range to ~5000 and that 40 was chosen to match previous chemical modeling.
  • C2H NE/SW T_rot contrast = 100 K / 60 K
    Assumed representative temperature contrast in Section 3.3, 'motivated by the SO results', used to test whether excitation can explain the C2H asymmetry; not measured for C2H.
  • C2H assumed T_rot in model comparison = 40 K
    Fixed rotational temperature for the observed C2H points in Fig. 11 (midplane temperature at r=200 au of the disk model).
  • Disk-averaged emitting area = radius 2.5 arcsec
    Assumed elliptical region for disk-averaged N_tot; paper notes it changes column densities but not T_rot.
  • FUV field scaling = chi* = 12000 chi0 (r/100 au)^-2
    Stellar FUV flux used in the chemical model, Section 4.1.
  • Initial elemental C/O = 0.44 (solar)
    Starting C/O of the 'low metals' abundances in Table 2; model grid scales O to reach C/O up to 2.
axioms (6)
  • domain assumption LTE + optically thin emission for column-density derivation (Eqs. 1-3)
    All column densities assume LTE and optically thin lines; the paper checks SO (tau<0.05), treats CS as lower limits due to possible moderate opacity, but C2H has no independent opacity check.
  • domain assumption Parametric 1+1D hydrostatic disk structure (Eqs. 6-11)
    The chemical model grid is computed on a temperature/density structure adopted from prior fits, assumed azimuthally symmetric and static; the azimuthal C/O inference is built on this axisymmetric backdrop.
  • domain assumption HCO+/H13CO+ intrinsic 12C/13C = 69 and optically thin H13CO+
    Used to invert Eq. (12) to obtain tau_HCO+ ~ 6-11; the paper acknowledges isotope-selective photodissociation may raise the ratio in the inner cavity.
  • domain assumption ALCHEMIC/KIDA network completeness and the tracer-C/O mapping
    The conclusion that SO is O-favored, C2H is C-favored, and CS is C/O-insensitive depends on the chemical network; the paper concedes missing sulfur pathways.
  • domain assumption 'Low metals' initial abundances (Table 2)
    Chemical model initial conditions adopted from Semenov et al. (2018).
  • ad hoc to paper Qualitative insensitivity of C/O-abundance trends to uncertain disk parameters
    The paper asserts (Section 4.2) that the qualitative dependence of CS/SO/C2H on C/O is robust to gas-to-dust ratio, sulfur depletion, UV penetration, and temperature structure, without a dedicated sensitivity study; this assertion is load-bearing for the C/O-gradient claim.

pith-pipeline@v1.3.0-alltime-deepseek · 30412 in / 19064 out tokens · 161715 ms · 2026-08-01T14:39:24.707750+00:00 · methodology

0 comments
read the original abstract

Late infall episodes are emerging as an important driver of disk evolution. Observed as filamentary streamers in molecular lines and scattered light, such accretion perturbs disk structures, yet its chemical consequences remain unconstrained. We present NOEMA 1.2 mm observations of AB Aur, a structured young Herbig disk showing evidence for ongoing infall and planet formation. We detect azimuthal chemical diversity: SO emission is enhanced in the northern disk near the inferred streamer-disk interaction region, while C$_2$H peaks on the opposite southern side; CS forms a nearly axisymmetric ring. HCN and HCO$^+$ peak near the dust continuum overdensity in the dust ring. Rotational diagram analyses show higher SO rotational temperatures and column densities in the north, whereas CS remains axisymmetric with lower rotational temperatures, suggesting that the species probe different disk layers. For C$_2$H, temperature variations may contribute to but cannot fully explain the asymmetries. The HCO$^+$/H$^{13}$CO$^+$ line ratio indicates that HCO$^+$ is optically thick across the molecular ring, while the elevated ratio inside the cavity suggests enhanced gas-phase $^{12}$C/$^{13}$C, consistent with isotope-selective photodissociation. Comparison with chemical models favors gas-phase C/O ratios near or above unity, with higher effective C/O in the C$_2$H-bright sector. We discuss two origins for the chemical asymmetries: (i) infall-induced heating and desorption of O-bearing ices enhance SO and lower gas-phase C/O near the streamer's impact site, and (ii) planet-driven substructures and localized heating or enhanced UV irradiation promote hydrocarbon-rich chemistry in the southern disk. These results highlight that environmental accretion and planet formation can jointly imprint azimuthal variations in disk chemistry, with potential impacts on forming planets' compositions.

Figures

Figures reproduced from arXiv: 2607.18683 by Dmitry Semenov, Edwige Chapillon, Haochang Jiang, Lucas M. Stapper, Myriam Benisty, Pablo Rivi\`ere-Marichalar, Thomas Henning, Vincent Pi\'etu.

Figure 1
Figure 1. Figure 1: The gallery of detected lines in peak intensity, integrated intensity, line width and line central velocity maps (from left to [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Left: De-projected, azimuthally averaged radial profiles of the full-disk (black), and along the red- and blue-shift sides of the disk (red and blue). In each panel, the radial locations of the ring peak and the gap bottom are labeled "BX" and "DX," re￾spectively, where X is the distance in au. Right: Teardrop plots. The solid line indicates the radial location of the continuum ring. And the dashed line ma… view at source ↗
Figure 3
Figure 3. Figure 3: Integrated intensity (Top) and peak intensity (Bottom) maps of CS J = 5 − 4, SO JN = 65 − 54 and stacked C2H. Overlaid contours show the r = 0.5 266 GHz continuum (Left, see also Appendix A) at 15, 30, and 45σ, where σ = 0.06 mJy beam−1 is the rms noise measured at emission free region. The CS maps shown are imaged with r = 0.5 for better angular resolution. Dashed lines indicate the disk major and minor a… view at source ↗
Figure 4
Figure 4. Figure 4: Integrated intensity (Top) and peak intensity (Bottom) maps of HCN J = 3 − 2, HCO+ J = 3 − 2 and H13CO+ J = 3 − 2. Contours and annotations are identical to [PITH_FULL_IMAGE:figures/full_fig_p005_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Rotational diagram fitting of SO based on three tran [PITH_FULL_IMAGE:figures/full_fig_p007_5.png] view at source ↗
Figure 7
Figure 7. Figure 7: Rotational diagram fitting for CS and SO, but using disk [PITH_FULL_IMAGE:figures/full_fig_p008_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: Peak column densities of C2H (dashed lines) as a func￾tion of assumed rotational temperature. The dashed vertical line marks the upper-state energy Eu for the C2H N = 3 − 2 transi￾tions. The red color represents the values averaged along the SW side, and the blue color represents the values averaged along the NE side of the disk. The peak column densities and rotational temperatures of CS (stars, [PITH_FU… view at source ↗
Figure 9
Figure 9. Figure 9: Derived C2H column densities on the northern and southern sides of the disk assuming a temperature contrast motivated by the SO rotational analysis, i.e., Trot = 100 K in the north and 60 K in the south. 200 400 Radius [au] 0.0 0.5 1.0 1.5 2.0 N [c m 2 ] 1e13 NE side, Trot = 100 K 200 400 Radius [au] 0.0 0.5 1.0 1.5 2.0 N [c m 2 ] 1e13 SW side, Trot = 60 K CS 5-4 SO 65-54 SO 56-45 SO 76-65 rot. diag [PITH… view at source ↗
Figure 10
Figure 10. Figure 10: Derived CS and SO column densities on the northern and southern sides of the disk under the same temperature contrast [PITH_FULL_IMAGE:figures/full_fig_p010_10.png] view at source ↗
Figure 12
Figure 12. Figure 12: The observationally derived column density ratio be [PITH_FULL_IMAGE:figures/full_fig_p012_12.png] view at source ↗
Figure 11
Figure 11. Figure 11: The observationally derived column density of CS, SO [PITH_FULL_IMAGE:figures/full_fig_p012_11.png] view at source ↗
Figure 13
Figure 13. Figure 13: The location of the asymmetric C2H ring (four￾components staked peak intensity map) relative to the proto￾planet candidates from Tang et al. (2017, pink), Boccaletti et al. (2020, purple), and Currie et al. (2022, 2025, yellow). J = 5 − 4, and C2H N = 3 − 2, J = 5 2 − 3 2 , corresponding to the transitions analyzed in this work. We assume Trot = 20 K for CS, and Trot = 40 K for both SO and C2H, motivated … view at source ↗
Figure 14
Figure 14. Figure 14: Comparison of the integrated C2H, CS, and SO line fluxes of AB Aur with those of other Herbig disks compiled by Booth et al. (2026). All line fluxes are scaled to a common distance of 150 pc and converted to the benchmark transitions analyzed in this work under the assumptions of optically thin LTE emission (see main text). Colored symbols identify individual disks, while arrows denote 3σ upper limits. Th… view at source ↗
Figure 15
Figure 15. Figure 15: Integrated intensity radial profiles of HCO [PITH_FULL_IMAGE:figures/full_fig_p016_15.png] view at source ↗

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

89 extracted references · 2 linked inside Pith

  1. [1]

    Armitage , P. J. 2015, arXiv e-prints, arXiv:1509.06382

  2. [2]

    A., Booth , R

    Bergin , E. A., Booth , R. A., Colmenares , M. J., & Ilee , J. D. 2024 a , , 969, L21

  3. [3]

    A., Bosman , A., Teague , R., et al

    Bergin , E. A., Bosman , A., Teague , R., et al. 2024 b , , 965, 147

  4. [4]

    A., Du , F., Cleeves , L

    Bergin , E. A., Du , F., Cleeves , L. I., et al. 2016, , 831, 101

  5. [5]

    2024, , 62, 157

    Birnstiel , T. 2024, , 62, 157

  6. [6]

    2026, arXiv e-prints, arXiv:2602.07731

    Blakely , D., Thompson , W., Johnstone , D., et al. 2026, arXiv e-prints, arXiv:2602.07731

  7. [7]

    2020, , 637, L5

    Boccaletti , A., Di Folco , E., Pantin , E., et al. 2020, , 637, L5

  8. [8]

    S., Calahan , J., Temmink , M., et al

    Booth , A. S., Calahan , J., Temmink , M., et al. 2026, , 171, 128

  9. [9]

    S., Temmink , M., van Dishoeck , E

    Booth , A. S., Temmink , M., van Dishoeck , E. F., et al. 2024, , 167, 165

  10. [10]

    S., van der Marel , N., Leemker , M., van Dishoeck , E

    Booth , A. S., van der Marel , N., Leemker , M., van Dishoeck , E. F., & Ohashi , S. 2021, , 651, L6

  11. [11]

    D., Alarc \'o n , F., Bergin , E

    Bosman , A. D., Alarc \'o n , F., Bergin , E. A., et al. 2021 a , , 257, 7

  12. [12]

    D., Alarc \'o n , F., Zhang , K., & Bergin , E

    Bosman , A. D., Alarc \'o n , F., Zhang , K., & Bergin , E. A. 2021 b , , 910, 3

  13. [13]

    P., & Henning , T

    Brauer , F., Dullemond , C. P., & Henning , T. 2008, , 480, 859

  14. [14]

    K., Bergin , E

    Calahan , J. K., Bergin , E. A., Bosman , A. D., et al. 2023, Nature Astronomy, 7, 49

  15. [15]

    J., & Ormel , C

    Calcino , J., Price , D. J., & Ormel , C. W. 2025, arXiv e-prints, arXiv:2510.05601

  16. [16]

    2022, , 134, 114501

    CASA Team , Bean , B., Bhatnagar , S., et al. 2022, , 134, 114501

  17. [17]

    I., Bergin , E

    Cleeves , L. I., Bergin , E. A., & Harries , T. J. 2015, , 807, 2

  18. [18]

    2025, , 990, L42

    Currie , T., Hashimoto , J., Aoyama , Y., et al. 2025, , 990, L42

  19. [19]

    2022, Nature Astronomy, 6, 751

    Currie , T., Lawson , K., Schneider , G., et al. 2022, Nature Astronomy, 6, 751

  20. [20]

    2016, , 826, 75

    Dong , R., Fung , J., & Chiang , E. 2016, , 826, 75

  21. [21]

    Draine , B. T. 1978, , 36, 595

  22. [22]

    Draine , B. T. & Bertoldi , F. 1996, , 468, 269

  23. [23]

    2023, in Astronomical Society of the Pacific Conference Series, Vol

    Drazkowska , J., Bitsch , B., Lambrechts , M., et al. 2023, in Astronomical Society of the Pacific Conference Series, Vol. 534, Astronomical Society of the Pacific Conference Series, ed. S. Inutsuka , Y. Aikawa , T. Muto , K. Tomida , & M. Tamura , 717

  24. [24]

    P., Isella , A., Andrews , S

    Dullemond , C. P., Isella , A., Andrews , S. M., Skobleva , I., & Dzyurkevich , N. 2020, , 633, A137

  25. [25]

    2024, , 689, L7

    Dutrey , A., Chapillon , E., Guilloteau , S., et al. 2024, , 689, L7

  26. [26]

    Eistrup , C., Walsh , C., & van Dishoeck , E. F. 2018, , 613, A14

  27. [27]

    Ferrari , P., Berden , G., Redlich , B., Waters , L. B. F. M., & Bakker , J. M. 2024, Nature Communications, 15, 5928

  28. [28]

    2017, , 846, L3

    Fuente , A., Baruteau , C., Neri , R., et al. 2017, , 846, L3

  29. [29]

    2010, , 524, A19

    Fuente , A., Cernicharo , J., Ag \'u ndez , M., et al. 2010, , 524, A19

  30. [30]

    Gaia Collaboration , Brown , A. G. A., Vallenari , A., et al. 2021, , 649, A1

  31. [31]

    G., et al

    Garufi , A., Ginski , C., van Holstein , R. G., et al. 2024, , 685, A53

  32. [32]

    2022, , 658, A104

    Garufi , A., Podio , L., Codella , C., et al. 2022, , 658, A104

  33. [33]

    2013, GILDAS: Grenoble Image and Line Data Analysis Software , Astrophysics Source Code Library, record ascl:1305.010

    Gildas Team . 2013, GILDAS: Grenoble Image and Line Data Analysis Software , Astrophysics Source Code Library, record ascl:1305.010

  34. [34]

    Hoch , K. K. W., Konopacky , Q. M., Theissen , C. A., et al. 2023, , 166, 85

  35. [35]

    A., Le Gal , R., et al

    Huang , J., Bergin , E. A., Le Gal , R., et al. 2024, , 973, 135

  36. [36]

    M., & Carrasco-Gonz \'a lez , C

    Jiang , H., Mac \' as , E., Guerra-Alvarado , O. M., & Carrasco-Gonz \'a lez , C. 2024, , 682, A32

  37. [37]

    W., Krijt , S., & Dong , R

    Jiang , H., Wang , Y., Ormel , C. W., Krijt , S., & Dong , R. 2023, , 678, A33

  38. [38]

    Kaufman , M. J. & Neufeld , D. A. 1996, , 456, 611

  39. [39]

    S., et al

    Keyte , L., Kama , M., Booth , A. S., et al. 2023, Nature Astronomy, 7, 684

  40. [40]

    D., Zhang , K., et al

    Krijt , S., Bosman , A. D., Zhang , K., et al. 2020, , 899, 134

  41. [41]

    G., & Dullemond , C

    Kuffmeier , M., Goicovic , F. G., & Dullemond , C. P. 2020, , 633, A3

  42. [42]

    S., & Haugb lle , T

    Kuffmeier , M., Jensen , S. S., & Haugb lle , T. 2023, European Physical Journal Plus, 138, 272

  43. [43]

    J., Le Gal , R., \"O berg , K

    Law , C. J., Le Gal , R., \"O berg , K. I., et al. 2026, , 997, 91

  44. [44]

    J., Le Gal , R., Yamato , Y., et al

    Law , C. J., Le Gal , R., Yamato , Y., et al. 2025, , 985, 84

  45. [45]

    J., Teague , R., Loomis , R

    Law , C. J., Teague , R., Loomis , R. A., et al. 2021, , 257, 4

  46. [46]

    I., Loomis , R

    Le Gal , R., \"O berg , K. I., Loomis , R. A., Pegues , J., & Bergner , J. B. 2019, , 876, 72

  47. [47]

    I., Teague , R., et al

    Le Gal , R., \"O berg , K. I., Teague , R., et al. 2021, , 257, 12

  48. [48]

    1996, , 311, 690

    Lee , H.-H., Herbst , E., Pineau des Forets , G., Roueff , E., & Le Bourlot , J. 1996, , 311, 690

  49. [49]

    A., Cleeves , L

    Loomis , R. A., Cleeves , L. I., \"O berg , K. I., et al. 2018, , 859, 131

  50. [50]

    A., Facchini , S., Benisty , M., et al

    Loomis , R. A., Facchini , S., Benisty , M., et al. 2025, , 984, L7

  51. [51]

    2023, , 677, L7

    Mah , J., Bitsch , B., Pascucci , I., & Henning , T. 2023, , 677, L7

  52. [52]

    C., & Kataoka , A

    Miotello , A., Kamp , I., Birnstiel , T., Cleeves , L. C., & Kataoka , A. 2023, in Astronomical Society of the Pacific Conference Series, Vol. 534, Protostars and Planets VII, ed. S. Inutsuka , Y. Aikawa , T. Muto , K. Tomida , & M. Tamura , 501

  53. [53]

    2017, , 849, 130

    Molyarova , T., Akimkin , V., Semenov , D., et al. 2017, , 849, 130

  54. [54]

    M \"u ller , H. S. P., Thorwirth , S., Roth , D. A., & Winnewisser , G. 2001, , 370, L49

  55. [55]

    2016, , 818, 16

    Musiolik , G., Teiser , J., Jankowski , T., & Wurm , G. 2016, , 818, 16

  56. [56]

    & Wurm , G

    Musiolik , G. & Wurm , G. 2019, , 873, 58

  57. [57]

    I., Murray-Clay , R., & Bergin , E

    \"O berg , K. I., Murray-Clay , R., & Bergin , E. A. 2011, , 743, L16

  58. [58]

    2025, Nature Astronomy, 9, 862

    Padoan , P., Pan , L., Pelkonen , V.-M., Haugb lle , T., & Nordlund , A . 2025, Nature Astronomy, 9, 862

  59. [59]

    E., Arzoumanian , D., Andre , P., et al

    Pineda , J. E., Arzoumanian , D., Andre , P., et al. 2023, in Astronomical Society of the Pacific Conference Series, Vol. 534, Protostars and Planets VII, ed. S. Inutsuka , Y. Aikawa , T. Muto , K. Tomida , & M. Tamura , 233

  60. [60]

    2024, , 689, A65

    Rampinelli , L., Facchini , S., Leemker , M., et al. 2024, , 689, A65

  61. [61]

    2019, , 879, L14

    Rivi \`e re-Marichalar , P., Fuente , A., Baruteau , C., et al. 2019, , 879, L14

  62. [62]

    2022, , 665, A61

    Rivi \`e re-Marichalar , P., Fuente , A., Esplugues , G., et al. 2022, , 665, A61

  63. [63]

    2020, , 642, A32

    Rivi \`e re-Marichalar , P., Fuente , A., Le Gal , R., et al. 2020, , 642, A32

  64. [64]

    2026, , 707, A348

    Rivi \`e re-Marichalar , P., Fuente , A., le Gal , R., et al. 2026, , 707, A348

  65. [65]

    2024, , 683, A141

    Rivi \`e re-Marichalar , P., Mac \' as , E., Baruteau , C., et al. 2024, , 683, A141

  66. [66]

    2018, , 617, A28

    Semenov , D., Favre , C., Fedele , D., et al. 2018, , 617, A28

  67. [67]

    2010, , 522, A42

    Semenov , D., Hersant , F., Wakelam , V., et al. 2010, , 522, A42

  68. [68]

    2005, , 621, 853

    Semenov , D., Pavlyuchenkov , Y., Schreyer , K., et al. 2005, , 621, 853

  69. [69]

    Semenov , D. A. 2017, ALCHEMIC: Advanced time-dependent chemical kinetics , Astrophysics Source Code Library, record ascl:1708.008

  70. [70]

    2024, , 633, 58

    Speedie , J., Dong , R., Hall , C., et al. 2024, , 633, 58

  71. [71]

    2025, , 981, L30

    Speedie , J., Dong , R., Teague , R., et al. 2025, , 981, L30

  72. [72]

    M., Hogerheijde , M

    Stapper , L. M., Hogerheijde , M. R., van Dishoeck , E. F., et al. 2024, , 682, A149

  73. [73]

    2017, , 840, 32

    Tang , Y.-W., Guilloteau , S., Dutrey , A., et al. 2017, , 840, 32

  74. [74]

    & Foreman-Mackey , D

    Teague , R. & Foreman-Mackey , D. 2018, Research Notes of the American Astronomical Society, 2, 173

  75. [75]

    R., et al

    Telleschi , A., G \"u del , M., Briggs , K. R., et al. 2007, , 468, 541

  76. [76]

    S., van der Marel , N., & van Dishoeck , E

    Temmink , M., Booth , A. S., van der Marel , N., & van Dishoeck , E. F. 2023, , 675, A131

  77. [77]

    2021, Molecular Astrophysics

    Tielens , A. 2021, Molecular Astrophysics

  78. [78]

    P., et al

    Trapman , L., Longarini , C., Rosotti , G. P., et al. 2025, , 984, L18

  79. [79]

    F., van't Hoff , M

    Tychoniec , ., van Dishoeck , E. F., van't Hoff , M. L. R., et al. 2021, , 655, A65

  80. [80]

    F., Kristensen , L

    van Dishoeck , E. F., Kristensen , L. E., Mottram , J. C., et al. 2021, , 648, A24

Showing first 80 references.