Pith. sign in

REVIEW 4 major objections 5 minor 73 references

Time evolution of o-H$_2$D$^+$, N$_2$D$^+$, and N$_2$H$^+$ during the high-mass star formation process

T0 review · 4 major / 5 minor · reviewed 2026-08-12 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗ Review JSON

Pith's one-line read The X(o-H2D+)/X(N2D+) ratio does not hold up as an evolutionary indicator across 40 massive clumps.

desk verdict Useful new dataset and a robust R_D trend, but the paper's central negative claim about the o-H2D+/N2D+ ratio is inferred rather than directly tested. read the letter →

arxiv 2411.14530 v1 pith:IEGS2YWC submitted 2024-11-21 astro-ph.GA astro-ph.SR

G. Sabatini , S.Bovino , E. Redaelli , F. Wyrowski , J. S. Urquhart , A. Giannetti , J. Brand , K. M. Menten This is my paper · ORCID
classification astro-ph.GAastro-ph.SR
keywords deuteriumfractionationchemicalclockshigh-massstarformationo-H2D+N2D+N2H+ATLASGALbeamdilution
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

The paper tests whether abundance ratios of deuterated molecules can order high-mass star-forming clumps by age. It finds that o-H2D+ abundance drops about six times from quiescent to YSO stages, while N2D+ drops only about three times, so the proposed X(o-H2D+)/X(N2D+) ratio is not a reliable clock. The deuteration fraction RD = N2D+/N2H+ does decline by nearly an order of magnitude, but its interpretation is complicated because the two molecules trace different spatial regions. The authors conclude that beam dilution and observational biases must be addressed before these tracers can calibrate evolutionary stage.

What carries the argument

The central object is the abundance ratio X(o-H2D+)/X(N2D+), proposed by earlier work as a chemical clock for massive clumps. The paper measures its ingredients from APEX spectra: o-H2D+ (110-111), N2H+ (4-3), and N2D+ (3-2) lines fitted with MCWeeds under LTE and cross-checked with RADEX non-LTE models. The luminosity-to-mass ratio L/M and a four-class evolutionary sequence (quiescent, protostellar, YSO, PDR) provide the time axis; the argument is that a reliable clock should show monotonic, class-separated abundance changes, which the ratio does not.

What would settle it

Spatially resolve o-H2D+ and N2D+ emission in a sample of the same clumps with an interferometer: if the ratio X(o-H2D+)/X(N2D+) becomes monotonic with L/M once both emissions are mapped at matched resolution, the paper's negative result would be a beam-dilution artifact; if the ratio stays flat, the chemical counter is truly unreliable. A simpler check is measuring N(N2D+) column densities with resolved maps to see whether the flat N(N2D+)-L/M trend is caused by increasing emitting area.

Watch

Extended reading notes

Core claim

In a sample of 40 ATLASGAL clumps observed with APEX, the paper finds that X(o-H2D+) decreases by about a factor of 6 from quiescent to YSO stages, whereas X(N2D+) decreases by about a factor of 3. Consequently, the recently proposed X(o-H2D+)/X(N2D+) ratio is not confirmed as a reliable evolutionary indicator for high-mass star formation. The deuteration fraction RD = N2D+/N2H+ decreases by almost an order of magnitude with evolution, making it a potential indicator, but the different spatial distribution of N2D+ and N2H+ complicates interpretation.

Load-bearing premise

That the molecules fill the telescope beam (beam-filling factor ηff = 1) for all tracers across all evolutionary stages, so that measured column densities are not systematically biased by the source size.

Editorial extensions

If this is right

  • If correct, the o-H2D+/N2D+ ratio should be avoided as a standalone evolutionary indicator for massive clumps.
  • X(o-H2D+) remains a sensitive tracer of early, cold stages, dropping by a factor of about 6 with evolution.
  • RD = N2D+/N2H+ could still serve as an evolutionary indicator, decreasing by nearly an order of magnitude from quiescent to YSO stages, though with spatial-distribution caveats.
  • Detection rates of both o-H2D+ and N2D+ decline with evolution (80% to 10%; 100% to 67%), matching the picture that deuterated ions vanish as sources heat up.
  • Correcting for beam dilution with spatially resolved observations is required before quantitative age determinations can be trusted.

Reading between the lines

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

  • If beam-filling factors differ systematically between stages, the factor-of-six vs factor-of-three contrast could shrink or grow; resolved maps of the two ions in the same clumps would test whether the ratio is truly flat.
  • The flat N(N2D+) column density with L/M, in contrast to the declining abundance, suggests the molecule is spread over a larger area in evolved clumps; this could be checked by comparing line widths and spatial extents.
  • The paper's negative result for the ratio does not rule out that the ratio works at core scales; single-dish beams average over clumps, so interferometric follow-up may recover a sharp trend.
  • The increase of X(N2H+) with evolution, if confirmed, offers a complementary path: pairing N2H+ with a deuterated counterpart may separate temperature and density effects.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

4 major / 5 minor

Summary. This paper tests two proposed deuterium-based chemical clocks for high-mass star formation. The authors use APEX single-dish observations of N2D+ (3-2) and N2H+ (4-3) toward 40 ATLASGAL clumps within 4 kpc (5 quiescent, 8 protostellar, 18 YSO, 9 PDR), combined with the o-H2D+ (110-111) spectra already published in Sabatini et al. (2020). Column densities and H2-relative abundances are derived with MCWeeds LTE fits and RADEX non-LTE models, and the results are examined as a function of evolutionary class and of L/M. Three main results are reported. First, detection rates decline with evolution for both deuterated species (N2D+: 100% to 67%; o-H2D+: 80% to 10%), while N2H+ is detected in all 40 sources. Second, X(o-H2D+) declines by a factor of about 6 from quiescent to YSO stages, X(N2D+) by about a factor of 3, and X(N2H+) increases slightly; the authors conclude that the X(o-H2D+)/X(N2D+) ratio proposed by Giannetti et al. (2019) is not confirmed as a reliable evolutionary indicator. Third, the deuterium fraction R_D = N(N2D+)/N(N2H+) decreases by nearly an order of magnitude along the evolutionary sequence, with class separations that are statistically significant (Anderson-Darling test) and robust between LTE and non-LTE analyses, although the interpretation is complicated by the different spatial distributions of the two tracers and by beam dilution.

Significance. If confirmed, the paper's central negative result matters for the field: it would show that the o-H2D+/N2D+ ratio does not provide the strong discriminating power suggested by Giannetti et al. (2019), and it strengthens the case for R_D and for interferometric calibration of these clocks in high-mass clumps. The study deserves credit for several concrete strengths: it is a larger and more homogeneous test than earlier single-filament or small-sample studies; it openly corrects a sqrt(pi) error in the previously published o-H2D+ column densities (Sect. 4.2.1); it checks for distance-dependent biases in line widths (Fig. 1); it verifies the R_D class separation with Anderson-Darling tests; it demonstrates the LTE/non-LTE consistency for R_D (Fig. 4b); and Table A.2 is a complete and reusable data product. The detection rates in Table 1 are a clean, analysis-independent result. However, the headline claim about the o-H2D+/N2D+ ratio is currently inferred rather than demonstrated: the ratio is never computed per source or statistically tested, the o-H2D+ detections in the evolved stages are extremely sparse, and the analysis-independence argument is not shown for this ratio.

major comments (4)
  1. [Sect. 4.2.3 and Sect. 5; Figs. 2 and 4a] The central negative claim—that the X(o-H2D+)/X(N2D+) ratio is not a reliable evolutionary indicator—is never tested directly. The ratio is not computed for individual sources, not plotted against L/M or evolutionary class, and the Anderson-Darling test used to validate R_D is not applied to it; the conclusion is instead inferred from the separate abundance trends in Figs. 2 and 4a. A factor of about 6 decline in X(o-H2D+) together with a factor of about 3 decline in X(N2D+) implies a ratio change of only about a factor of 2, but whether this is too small to be a useful indicator depends on the per-source scatter of the ratio, which is not shown. Table A.2 shows that only nine sources have both o-H2D+ and N2D+ detections (four quiescent, one protostellar, two YSO, two PDR), so a detection-only test would be severely underpowered; the paper should either present the per-source ratio with an upper-limit treatment of the remaining sources and a class-separation test, or explicitly state that the censoring prevents such a test and qualify the conclusion accordingly.
  2. [Sect. 4.2.2 and Fig. 4b] The assertion in Sect. 4.2.2 that the evolutionary trends of the abundances and abundance ratios are not affected by the choice of analysis is demonstrated only for R_D (Fig. 4b). The non-LTE corrections differ substantially between the two deuterated species: o-H2D+ column densities are overestimated by factors of 1.2-1.6, whereas N2D+ is overestimated by factors of 1.3-5, with the correction depending on the assumed volume density for each source (Table A.2). Because the corrections enter asymmetrically, the LTE trend of the X(o-H2D+)/X(N2D+) ratio could flatten, steepen, or reverse under non-LTE assumptions, and the non-LTE version of this ratio is never shown. The paper should present the non-LTE version of the ratio (as it does for R_D in Fig. 4b) to substantiate the analysis-independence claim; the necessary quantities are already in Table A.2.
  3. [Table 1; Sect. 4.2.3; Fig. 4a] The quantitative comparison between the X(o-H2D+) decline (factor about 6) and the X(N2D+) decline (factor about 3) rests on very unequal detection completeness. In the YSO class, o-H2D+ is detected in only about 10% of the sources (roughly 2 of 18) while N2D+ is detected in 67%; non-detections are shaded in Fig. 2, but no upper-limit treatment is described, and the class medians quoted in Sect. 6 and shown in Fig. 4a are computed from detections only. The YSO median of X(o-H2D+) is therefore based on a handful of detections, and the amplitude of the abundance decline—and hence the implied factor of about 2 dynamic range of the abundance ratio—is not robust. A censored-data treatment of the non-detections and a statement of the number of detections entering each median are needed before the factor-6 versus factor-3 comparison can carry the weight it is given in the conclusions.
  4. [Sect. 4.1 vs Sect. 5] There is an internal tension between the beam-dilution assumption and the spatial-distribution interpretation. Section 4.1 argues that o-H2D+ and N2D+ are chemically linked and should have similar emission extensions, so that eta_ff < 1 would cause a comparable underestimation of the two column densities. Section 5, by contrast, explains the weaker decline of X(N2D+) by its emission arising not only near the YSO but also from the outer envelope—that is, by a different spatial distribution of the two tracers. If the distributions differ, and differ in a stage-dependent way, the comparable-underestimation argument cannot hold simultaneously, and differential beam dilution would bias the very ratio whose reliability is being tested. The manuscript should reconcile these two statements and present the ratio test under explicit assumptions for eta_ff (e.g., equal eta_ff for the two deuterated species versus stage-dependent eta_ff), since the paper currently moves between a chemical-clock conclusion and an observational-bias conclusion.
minor comments (5)
  1. [Sect. 4.2.1 and Table A.2] The symbol N_LTE is used for the LTE-derived column density while N_NLTE denotes the non-LTE value; since 'NLTE' conventionally means non-LTE, expressions such as 'Figure 3a compares NLTE(N2H+) with NLTE(N2D+)' in Sect. 4.2.3 are easily misread. Please rename the LTE column density (e.g., N_fit) and relabel the corresponding table columns.
  2. [Abstract] In the arXiv abstract, the molecular formula 'N$_2$d$^+$' appears with a lowercase 'd'; it should read N2D+.
  3. [Fig. 1 caption] The caption states that the orange and magenta lines represent the median FWHM values of 'N2H+ and N2H+'; the second species should be N2D+.
  4. [Sect. 5] The phrase 'formation and destruction of deutereted molecules' contains a typo; it should read 'deuterated molecules.'
  5. [Sect. 3.2] The sentence 'The final mean T_sys lies between ~600 and 1200' is missing the unit of temperature (K).

Circularity Check

0 steps flagged · score 2.0 of 10

No significant circularity. The tested o-H2D+/N2D+ indicator and the o-H2D+ dataset trace to same-author prior work, but the paper uses new independent N2D+ and N2H+ observations and reaches a negative conclusion against its own group's proposal, so no step reduces to its inputs.

full rationale

The paper's central claim — that X(o-H2D+)/X(N2D+) is not confirmed as a reliable evolutionary indicator while R_D = N2D+/N2H+ decreases with stage — is an empirical comparison rather than a derivation that reduces to its inputs. Abundances are measured from new APEX N2D+ (3-2) and N2H+ (4-3) observations plus previously published o-H2D+ data; evolutionary classes and L/M come from independent 3-70 um continuum and IR criteria (Urquhart et al. 2022; Koenig et al. 2017), not from the deuterated species under test. No fitted constant is relabeled as a prediction: the factor of ~6 (o-H2D+) versus ~3 (N2D+) decrease is a comparison of class medians (Fig. 4a), and the ratio's unreliability is inferred from those two separate trends. Because X(o-H2D+)/X(N2D+) equals N(o-H2D+)/N(N2D+) (the common N(H2) denominator cancels), the comparison is not forced by definition. The self-referential elements are provenance, not load-bearing: the tested ratio was proposed by Giannetti et al. (2019) and the o-H2D+ data come from Sabatini et al. (2020), both with overlapping authorship (Sabatini, Bovino, Giannetti), but the conclusion is negative — it fails to confirm the group's own proposal — and the new N2D+/N2H+ data are independent, with R_D corroborated by external work (Chen et al. 2011; Fontani et al. 2011; Miettinen 2020). Flagged limitations that affect validity, not circularity: Sect. 4.1 admits 'we cannot exclude the possibility that the beam-filling factor is eta_ff < 1... we cannot quantify eta_ff solely on the basis of the data we have at hand'; Sect. 4.2.2 asserts that 'the evolutionary trends of the abundances and abundance ratios given in the following sections are not affected by the choice of analysis,' yet the NLTE comparison is displayed only for R_D (Fig. 4b) while N2D+ NLTE corrections reach factors of 1.3-5 (Table A.2); and the o-H2D+/N2D+ ratio is never directly plotted or Anderson-Darling tested per stage. These are evidence-quality gaps in the central negative result, not circular reductions. Score 2 reflects the minor same-group provenance of the indicator and of one tracer's dataset.

Assumptions & free parameters 1 free parameters · 4 assumptions · 0 invented entities

No new physical entities are introduced. The central claims rest on standard radiative-transfer assumptions (LTE, beam filling, temperature coupling) and on the external evolutionary classification of the ATLASGAL clumps; the most fragile is the unquantified beam filling factor.

free parameters (1)
  • Beam filling factor eta_ff = 1 (assumed)
    Adopted to convert main-beam temperatures to column densities; the authors state they cannot quantify it from the data and that values below 1 would lower the N2D+ and o-H2D+ column densities.
assumptions (4)
  • domain assumption LTE conditions for the N2H+ (4-3) line in the primary analysis
    MCWeeds LTE fits with Tex = Tdust are used for the X(N2H+) trend in Fig. 2; the paper's RADEX NLTE grid gives NNLTE/NLTE up to 30 at the low-density end, so the assumption is formally violated and relies on the claim that trends are unchanged.
  • ad hoc to paper Extended emission with beam filling factor eta_ff = 1
    Invoked in Sect. 4.1 for all tracers; the authors explicitly state that the beam filling factor cannot be constrained from the available single-dish data.
  • domain assumption Gas kinetic temperature equals dust temperature (Tkin = Tdust)
    Used to set the excitation temperature in MCWeeds and the kinetic temperature in RADEX; the paper tests a 40 percent variation and reports minor impact on column densities.
  • domain assumption The four evolutionary classes form a temporal sequence
    The classification into quiescent, protostellar, YSO and PDR relies on mid-infrared and 70 micron morphology plus L/M, carried over from Koenig et al. (2017) and Urquhart et al. (2022); the interpretation of abundance trends as time evolution depends on this.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Time evolution of o-H$_2$D$^+$, N$_2$D$^+$, and N$_2$H$^+$ during the high-mass star formation process." pith.science (2026). https://pith.science/paper/IEGS2YWC

@misc{pith2026241114530,
  author       = {Pith},
  title        = {Pith review of: Time evolution of o-H$_2$D$^+$, N$_2$D$^+$, and N$_2$H$^+$ during the high-mass star formation process},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/IEGS2YWC}},
  note         = {Machine review of arXiv:2411.14530}
}
abstract

Deuterium fractionation is a well-established evolutionary tracer in low-mass star formation, but its applicability to the high-mass regime remains an open question. The abundances and ratios of deuterated species have often been proposed as reliable evolutionary indicators for different stages of the high-mass star formation. We investigate the role of N$_2$H$^+$ and key deuterated molecules as tracers of the different stages of the high-mass star formation, and test whether their abundance ratios can serve as reliable evolutionary indicators. We conducted APEX observations of o-H$_2$D$^+$ (1$_{10}$-1$_{11}$), N$_2$H$^+$ (4-3), and N$_2$d$^+$ (3-2) in 40 high-mass clumps at different evolutionary stages, selected from the ATLASGAL survey. Molecular column densities ($N$) and abundances ($X$), were derived through spectral line modelling, both under local thermodynamic equilibrium (LTE) and non-LTE conditions. The $N$(o-H$_2$D$^+$) show the smallest deviation from LTE results when derived under non-LTE assumptions. In contrast, N$_2$D$^+$ shows the largest discrepancy between the $N$ derived from LTE and non-LTE. In all the cases discussed, we found that $X$(o-H$_2$D$^+$) decreases more significantly with time than in the case of $X$(N$_2$D$^+$); whereas $X$(N$_2$H$^+$) increases slightly. Therefore, the validity of the recently proposed $X$(o-H$_2$D$^+$)/$X$(N$_2$D$^+$) ratio as a reliable evolutionary indicator was not observed for this sample. While the deuteration fraction derived from N$_2$D$^+$ and N$_2$H$^+$ clearly decreases with clump evolution, the interpretation of this trend is complex, given the different distribution of the two tracers. Our results suggest that a careful consideration of the observational biases and beam-dilution effects are crucial for an accurate interpretation of the evolution of the deuteration process during the high-mass star formation process.

Figures

Figures reproduced from arXiv: 2411.14530 by the authors.

Figure 1
Figure 1. Heliocentric distance versus the FWHM of (a) N [PITH_FULL_IMAGE:figures/full_fig_p004_1.png] view at source ↗
Figure 2
Figure 2. Correlations between L/M and the abundances of o￾H2D + , N2D + , and N2H + obtained with the LTE analysis. Blue dots refer to sources associated with the evolutionary sequence defined in Sect. 2.2, whilst grey dots are associated with PDRs. Shaded dots refer to sources in which o-H2D + is not detected. The blue dashed lines show the result of a linear least-squares fit to the data, while the cyan shaded areas show t… view at source ↗
Figure 4
Figure 4. Summary of the observed evolutionary trends. Panel (a): [PITH_FULL_IMAGE:figures/full_fig_p007_4.png] view at source ↗

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

73 extracted references · 40 canonical work pages

  1. [1]

    & Hirao, T

    Amano, T. & Hirao, T. 2005, JMoSp, 233, 7

    work page 2005

  2. [2]

    2005, JMoSp, 234, 170 Astropy Co., Price-Whelan, A

    Amano, T., Hirao, T., & Takano, J. 2005, JMoSp, 234, 170 Astropy Co., Price-Whelan, A. M., Sip˝ocz, B. M., et al. 2018, AJ, 156, 123 Astropy Co., Robitaille, T. P., Tollerud, E. J., et al. 2013, A&A, 558, A33

    work page 2005

  3. [3]

    2020, MNRAS, 495, 2524

    Balanca, C., Scribano, Y ., Loreau, J., Lique, F., & Feautrier, N. 2020, MNRAS, 495, 2524

    work page 2020

  4. [4]

    Bergin, E. A. & Tafalla, M. 2007, ARA&A, 45, 339

    2007

  5. [5]

    A., & Sridharan, T

    Beuther, H., Zhang, Q., Bergin, E. A., & Sridharan, T. K. 2009, AJ, 137, 406 Article number, page 8 of 13 G. Sabatini et al.: Time evolution of o-H2D+, N2D+, and N2H+ during the high-mass star formation process

    work page 2009

  6. [6]

    2019, ApJ, 887, 224

    Bovino, S., Ferrada-Chamorro, S., Lupi, A., et al. 2019, ApJ, 887, 224

    2019

  7. [7]

    2021, A&A, 654, A34

    Bovino, S., Lupi, A., Giannetti, A., et al. 2021, A&A, 654, A34

    work page 2021

  8. [8]

    J., Noriega-Crespo, A., Mizuno, D

    Carey, S. J., Noriega-Crespo, A., Mizuno, D. R., et al. 2009, PASP, 121, 76

    2009

Show all 73 references
  1. [9]

    & Ceccarelli, C

    Caselli, P. & Ceccarelli, C. 2012, A&A Rev., 20, 56

    2012

  2. [10]

    2008, A&A, 492, 703

    Caselli, P., Vastel, C., Ceccarelli, C., et al. 2008, A&A, 492, 703

    2008

  3. [11]

    M., Tafalla, M., Dore, L., & Myers, P

    Caselli, P., Walmsley, C. M., Tafalla, M., Dore, L., & Myers, P. C. 1999, ApJ, 523, L165

    1999

  4. [12]

    2014, in Protostars and Planets VI, ed

    Ceccarelli, C., Caselli, P., Bockelée-Morvan, D., et al. 2014, in Protostars and Planets VI, ed. H. Beuther, R. S. Klessen, C. P. Dullemond, & T. Henning, 859

    2014

  5. [13]

    2023, in Astronomical Society of the Pacific Conference Series, V ol

    Ceccarelli, C., Codella, C., Balucani, N., et al. 2023, in Astronomical Society of the Pacific Conference Series, V ol. 534, Protostars and Planets VII, ed. S. Inutsuka, Y . Aikawa, T. Muto, K. Tomida, & M. Tamura, 379

    2023

  6. [14]

    2011, ApJ, 743, 196

    Chen, H.-R., Liu, S.-Y ., Su, Y .-N., & Wang, M.-Y . 2011, ApJ, 743, 196

    2011

  7. [15]

    L., Meade, M

    Churchwell, E., Babler, B. L., Meade, M. R., et al. 2009, PASP, 121, 213

    2009

  8. [16]

    S., et al

    Contreras, Y ., Schuller, F., Urquhart, J. S., et al. 2013, A&A, 549, A45

    2013

  9. [17]

    M., et al

    Crapsi, A., Caselli, P., Walmsley, C. M., et al. 2005, ApJ, 619, 379

    2005

  10. [18]

    2016, A&A, 586, A149

    Csengeri, T., Leurini, S., Wyrowski, F., et al. 2016, A&A, 586, A149

    2016

  11. [19]

    & Lepp, S

    Dalgarno, A. & Lepp, S. 1984, ApJ, 287, L47

    1984

  12. [20]

    2021, MNRAS, 504, 2742

    Elia, D., Merello, M., Molinari, S., et al. 2021, MNRAS, 504, 2742

    2021

  13. [21]

    H., Stutzki, J., & Wiedner, M

    Emprechtinger, M., Caselli, P., V olgenau, N. H., Stutzki, J., & Wiedner, M. C. 2009, A&A, 493, 89

    2009

  14. [22]

    2016, A&A, 592, A21

    Feng, S., Beuther, H., Zhang, Q., et al. 2016, A&A, 592, A21

    2016

  15. [23]

    2011, A&A, 529, L7

    Fontani, F., Palau, A., Caselli, P., et al. 2011, A&A, 529, L7

    2011

  16. [24]

    2007, A&A, 470, 639

    Fontani, F., Pascucci, I., Caselli, P., et al. 2007, A&A, 470, 639

    2007

  17. [25]

    2019, A&A, 621, L7

    Giannetti, A., Bovino, S., Caselli, P., et al. 2019, A&A, 621, L7

    2019

  18. [26]

    2017, A&A, 603, A33

    Giannetti, A., Leurini, S., Wyrowski, F., et al. 2017, A&A, 603, A33

    2017

  19. [27]

    2014, A&A, 570, A65

    Giannetti, A., Wyrowski, F., Brand, J., et al. 2014, A&A, 570, A65

    2014

  20. [28]

    Goldsmith, P. F. 2001, ApJ, 557, 736 Güsten, R., Nyman, L. Å., Schilke, P., et al. 2006, A&A, 454, L13

    2001

  21. [29]

    & van Dishoeck, E

    Herbst, E. & van Dishoeck, E. F. 2009, ARA&A, 47, 427

    2009

  22. [30]

    2010, A&A, 513, A41

    Hily-Blant, P., Walmsley, M., Pineau Des Forêts, G., & Flower, D. 2010, A&A, 513, A41

    2010

  23. [31]

    M., Foster, J

    Hoq, S., Jackson, J. M., Foster, J. B., et al. 2013, ApJ, 777, 157

    2013

  24. [32]

    Hugo, E., Asvany, O., & Schlemmer, S. 2009, J. Chem. Phys., 130, 164302

    2009

  25. [33]

    Hunter, J. D. 2007, Computing In Science & Engineering, 9, 90

    2007

  26. [34]

    M., et al

    Izumi, N., Sanhueza, P., Koch, P. M., et al. 2024, ApJ, 963, 163

    2024

  27. [35]

    Kennicutt, R. C. 2005, in Massive Star Birth: A Crossroads of Astrophysics, ed. R. Cesaroni, M. Felli, E. Churchwell, & M. Walmsley, V ol. 227, 3–11

    2005

  28. [36]

    2014, IEEE Transactions on Tera- hertz Science and Technology, 4, 588

    Klein, T., Ciechanowicz, M., Leinz, C., et al. 2014, IEEE Transactions on Tera- hertz Science and Technology, 4, 588

    2014

  29. [37]

    C., Caselli, P., et al

    Kong, S., Tan, J. C., Caselli, P., et al. 2016, ApJ, 821, 94 König, C., Urquhart, J. S., Csengeri, T., et al. 2017, A&A, 599, A139

    2016

  30. [38]

    2022, ApJ, 939, 102

    Li, S., Sanhueza, P., Lu, X., et al. 2022, ApJ, 939, 102

    2022

  31. [39]

    2023, ApJ, 949, 109

    Li, S., Sanhueza, P., Zhang, Q., et al. 2023, ApJ, 949, 109

    2023

  32. [40]

    2020, A&A, 635, A188

    Lin, S.-J., Pagani, L., Lai, S.-P., Lefèvre, C., & Lique, F. 2020, A&A, 635, A188

    2020

  33. [41]

    Loison, J.-C., Wakelam, V ., Gratier, P., & Hickson, K. M. 2019, MNRAS, 484, 2747

    2019

  34. [42]

    2011, A&A, 526, A47

    Maret, S., Hily-Blant, P., Pety, J., Bardeau, S., & Reynier, E. 2011, A&A, 526, A47

    2011

  35. [43]

    2020, A&A, 634, A115

    Miettinen, O. 2020, A&A, 634, A115

    2020

  36. [44]

    2011, A&A, 534, A134

    Miettinen, O., Hennemann, M., & Linz, H. 2011, A&A, 534, A134

    2011

  37. [45]

    2008, A&A, 481, 345

    Molinari, S., Pezzuto, S., Cesaroni, R., et al. 2008, A&A, 481, 345

    2008

  38. [46]

    2010, PASP, 122, 314

    Molinari, S., Swinyard, B., Bally, J., et al. 2010, PASP, 122, 314

    2010

  39. [47]

    2023, ApJ, 950, 148 Müller, H

    Morii, K., Sanhueza, P., Nakamura, F., et al. 2023, ApJ, 950, 148 Müller, H. S. P., Schlöder, F., Stutzki, J., & Winnewisser, G. 2005, JMoSt, 742, 215 Öberg, K. I. & Bergin, E. A. 2021, Phys. Rep., 893, 1

    2023

  40. [48]

    Pagani, L., Salez, M., & Wannier, P. G. 1992, A&A, 258, 479

    1992

  41. [49]

    2010, JSS, Articles, 35, 1

    Patil, A., Huard, D., & Fonnesbeck, C. 2010, JSS, Articles, 35, 1

    2010

  42. [50]

    2012, ApJ, 751, 135

    Pillai, T., Caselli, P., Kauffmann, J., et al. 2012, ApJ, 751, 135

    2012

  43. [51]

    2020, A&A, 644, A29

    Redaelli, E., Bizzocchi, L., & Caselli, P. 2020, A&A, 644, A29

    2020

  44. [52]

    2019, A&A, 629, A15

    Redaelli, E., Bizzocchi, L., Caselli, P., et al. 2019, A&A, 629, A15

    2019

  45. [53]

    2021, A&A, 650, A202

    Redaelli, E., Bovino, S., Giannetti, A., et al. 2021, A&A, 650, A202

    2021

  46. [54]

    2022, ApJ, 936, 169

    Redaelli, E., Bovino, S., Sanhueza, P., et al. 2022, ApJ, 936, 169

    2022

  47. [55]

    2021, A&A, 652, A71

    Sabatini, G., Bovino, S., Giannetti, A., et al. 2021, A&A, 652, A71

    2021

  48. [56]

    2020, A&A, 644, A34

    Sabatini, G., Bovino, S., Giannetti, A., et al. 2020, A&A, 644, A34

    2020

  49. [57]

    2023, ApJ, 947, L18

    Sabatini, G., Bovino, S., & Redaelli, E. 2023, ApJ, 947, L18

    2023

  50. [58]

    2022, ApJ, 936, 80

    Sabatini, G., Bovino, S., Sanhueza, P., et al. 2022, ApJ, 936, 80

    2022

  51. [59]

    2019, MNRAS, 490, 4489

    Sabatini, G., Giannetti, A., Bovino, S., et al. 2019, MNRAS, 490, 4489

    2019

  52. [60]

    2022, ApJ, 925, 144

    Sakai, T., Sanhueza, P., Furuya, K., et al. 2022, ApJ, 925, 144

    2022

  53. [61]

    2019, ApJ, 886, 102

    Sanhueza, P., Contreras, Y ., Wu, B., et al. 2019, ApJ, 886, 102

    2019

  54. [62]

    1996, A&A, 309, 827

    Saraceno, P., Andre, P., Ceccarelli, C., Griffin, M., & Molinari, S. 1996, A&A, 309, 827

    1996

  55. [63]

    Scholz, F. W. & Stephens, M. A. 1987, JASA, 82, 918

    1987

  56. [64]

    M., Contreras, Y ., et al

    Schuller, F., Menten, K. M., Contreras, Y ., et al. 2009, A&A, 504, 415 Sipilä, O., Caselli, P., Redaelli, E., Juvela, M., & Bizzocchi, L. 2019, MNRAS, 487, 1269 Sipilä, O., Caselli, P., & Taquet, V . 2016, A&A, 591, A9

    2009

  57. [65]

    Smartt, S. J. 2009, ARA&A, 47, 63

    2009

  58. [66]

    2024, A&A, 687, A70

    Socci, A., Sabatini, G., Padovani, M., Bovino, S., & Hacar, A. 2024, A&A, 687, A70

    2024

  59. [67]

    D., Henkel, C., Wyrowski, F., et al

    Tang, X. D., Henkel, C., Wyrowski, F., et al. 2018, A&A, 611, A6

    2018

  60. [68]

    S., Figura, C., Wyrowski, F., et al

    Urquhart, J. S., Figura, C., Wyrowski, F., et al. 2019, MNRAS, 484, 4444

    2019

  61. [69]

    S., König, C., Giannetti, A., et al

    Urquhart, J. S., König, C., Giannetti, A., et al. 2018, MNRAS, 473, 1059

    2018

  62. [70]

    S., Wells, M

    Urquhart, J. S., Wells, M. R. A., Pillai, T., et al. 2022, MNRAS, 510, 3389 van der Tak, F. F. S., Black, J. H., Schöier, F. L., Jansen, D. J., & van Dishoeck, E. F. 2007, A&A, 468, 627 van Dishoeck, E. F. & Blake, G. A. 1998, ARA&A, 36, 317

    2022

  63. [71]

    2006, ApJ, 645, 1198

    Vastel, C., Caselli, P., Ceccarelli, C., et al. 2006, ApJ, 645, 1198

    2006

  64. [72]

    M., et al

    Wienen, M., Wyrowski, F., Menten, K. M., et al. 2015, A&A, 579, A91

    2015

  65. [73]

    (c1)” and “(c2)

    Zinnecker, H. & Yorke, H. W. 2007, ARA&A, 45, 481 Article number, page 9 of 13 A&A proofs: manuscript no. Sabatini24_aa51659-24_finalproofs Appendix A: Physical and chemical properties of the clumps Table A.1 presents a comparison between the main physical properties and evolu...

    2017

Pith tools

Reviewed August 12, 2026 · model on record in the stance chip above.