Pith. sign in

REVIEW 3 major objections 5 minor 300 references

This review argues the two best-studied cold clouds reveal a universal chemistry: complex organic molecule production is nearly independent of metallicity.

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 →

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

T0 review · deepseek-v4-flash

2026-08-01 02:12 UTC pith:M2W2CYKG

load-bearing objection Solid, candid field review; the 'representative not outlier' thesis overreaches and needs tempering before publication. the 3 major comments →

arxiv 2607.25515 v1 pith:M2W2CYKG submitted 2026-07-28 astro-ph.GA astro-ph.EPastro-ph.SR

Chemistry of Dark Molecular Clouds

Yuri Aikawa , Izaskun Jimenez-Serra , Paola Caselli This is my paper
classification astro-ph.GA astro-ph.EPastro-ph.SR
keywords molecular cloudsastrochemistryinterstellar icesTMC-1prestellar corescomplex organic moleculesinterstellar moleculesmetallicity
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.

This review argues that the cold, starless clouds TMC-1 CP and L1544 — long treated as special — are actually representative sample chambers for how interstellar chemistry works, and that the chemical recipes made there carry into stars, planets, and comets. It assembles the new deep radio surveys that have greatly expanded the molecular inventory of dark clouds, including aromatic ring molecules, and pairs them with JWST ice observations showing that the major ices are frozen out before stars form. The review's sharpest quantitative claim is that the production efficiency of complex organic molecules relative to methanol is essentially independent of metallicity: ratios lie within a factor of ten across sources spanning 0.25 to 2 times solar. If correct, the chemistry of planet-forming material is set by universal cold-cloud processes rather than by a galaxy's metal content.

Core claim

On the paper's own terms, the central discovery is that the deep, thousand-hour spectral surveys toward TMC-1 CP and the multi-wavelength study of L1544 converge on a single picture: dark-cloud chemistry is generic. TMC-1 CP's rich inventory — carbon chains, aromatic molecules, isomers, anions — is not a freak accident of that one core but the expected outcome of quiescent, well-shielded gas; L1544's catastrophic freeze-out of CO and its methanol peak are the standard prestellar-core configuration. A second, quantitative discovery: comparing column-density ratios of complex organic molecules (COMs) to CH3OH across environments from low-metallicity outer Galaxy hot cores to the metal-rich Gal

What carries the argument

The argument is carried by two kinds of observations: ultra-deep radio line surveys of TMC-1 CP that have expanded the known interstellar molecular inventory by about a third (including aromatic ring molecules), and infrared absorption spectra of ices toward background stars, anchored by millimeter observations of the prestellar core L1544. For the metallicity claim, the key device is the COM/CH3OH column-density ratio: normalizing to methanol cancels absolute abundance uncertainties (such as the gas-to-dust scaling), making the ratio a robust measure of complex organic molecule production efficiency across hot cores, starless cores, and clouds with 0.25–2× solar metallicity.

Load-bearing premise

The metallicity claim rests on assuming that different complex organic molecules desorb from ice with broadly similar efficiencies in starless cores (non-thermal desorption) and hot cores (thermal sublimation); if species desorb at very different rates, the uniform COM/CH3OH ratios would reflect desorption rather than production.

What would settle it

Measure the desorption efficiency of specific COMs (e.g., CH3CHO, CH3CN, HCOOCH3) relative to CH3OH in laboratory ice analogs under both reactive/cosmic-ray desorption and thermal sublimation; if the ratios differ by more than a factor of a few between the two desorption regimes, the Fig. 10 flat trend cannot be read as metallicity-independent production. Alternatively, a larger sample of low-metallicity hot cores where CH3OH is detectable would falsify the claim if any COM/CH3OH ratio falls outside the factor-of-10 band systematically with metallicity.

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

If this is right

  • Molecules detected first in TMC-1 CP, such as benzonitrile and other aromatic species, should be widespread in other dark clouds and searchable there.
  • Catastrophic CO freeze-out in dense prestellar cores is the normal trigger for methanol and larger complex organic molecule formation, not a peculiarity of L1544.
  • The ices that later appear in comets and protoplanetary disks are largely assembled before any star forms, in the prestellar phase.
  • The flat COM/CH3OH ratio across metallicity means that the efficiency of making complex organic molecules is set by cold-cloud ice chemistry, so planet-forming material in low-metallicity galaxies can be as chemically rich as in the Solar neighborhood.
  • Carbon-chain/aromatic chemical differentiation can be used as an evolutionary clock for starless cores.

Where Pith is reading between the lines

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

  • If the representative claim holds, future surveys can use TMC-1 CP and L1544 as calibrators to invert observations of more distant or more massive clouds into physical conditions and chemical ages, rather than treating each detection as a unique event.
  • A testable extension: the metallicity-independence claim predicts that COM/CH3OH ratios in low-metallicity galaxies with detected COMs should stay within a factor of ~10 of the Galactic values even as CH3OH itself becomes harder to form; this can be checked with JWST ice and ALMA gas observations of the same Magellanic Cloud sources.
  • The flat ratio could instead reflect desorption physics rather than production; comparing multiple COM ratios (e.g., CH3CHO/CH3OH vs CH3CN/CH3OH) across objects with different desorption mechanisms would separate the two.
  • The review's framework implies that the chemical complexity available to emerging planets is largely a boundary condition set by the parent cloud, with disk chemistry then recycling this inheritance; as such, searches for prebiotic molecules in disks should prioritize sources that accreted from prestellar cores resembling L1544.

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

3 major / 5 minor

Summary. This review synthesizes current understanding of the chemistry of dark molecular clouds, with emphasis on the deep line surveys toward TMC-1 CP and the prestellar core L1544. It covers gas-phase and grain-surface chemistry, isotope fractionation, molecular inventories, ice observations with JWST, core-to-core comparisons, and the chemistry of giant molecular clouds in the Galactic disk, the Galactic Center, the outer Galaxy, and the Magellanic Clouds. Two claims are presented as the review's main synthesis: (1) TMC-1 CP and L1544 are 'not outliers but representative laboratories' of molecular cloud physics and chemistry; and (2) from Fig. 10, the efficiency of complex organic molecule (COM) production is not significantly affected by metallicity, as judged by COM/CH3OH column-density ratios lying within a factor of 10 over metallicities 0.25–2× solar.

Significance. If substantiated, the representativeness claim would give the deep surveys of TMC-1 CP and L1544 general validity as calibrators of astrochemical models and of the chemical inheritance from clouds to star- and planet-forming regions. The metallicity claim would provide a useful observational constraint on COM formation across galaxies. The review is genuinely useful as an up-to-date and comprehensive survey: it compiles a large molecular inventory in the Supplemental Tables, identifies where current models fail (e.g., aromatics under-predicted by orders of magnitude in §3.1.4, S-species in §3.1.1.5), and is appropriately hedged about tentativeness of ice COMs (§6) and unresolved bottom-up versus top-down scenarios. Its main weaknesses are not technical but interpretive: the two headline claims are stronger than the evidence presented, and one of them rests on an explicitly assumed but circularly supported desorption premise.

major comments (3)
  1. [§5.2, Fig. 10; Summary Point 7] The metallicity-independence claim depends on the premise stated in §5.2: 'We assume that desorption efficiencies are broadly similar among COMs, supported by the absence of systematic differences in COM/CH3OH ratios between hot cores and starless objects.' This support is circular: the absence of systematic ratio differences is the same pattern used to conclude that COM production efficiency is metallicity-independent. The objects in Fig. 10 release COMs by entirely different mechanisms — thermal sublimation at ≳100 K in hot cores versus reactive/cosmic-ray desorption at ~10 K in TMC-1 CP and L1544 — and species-dependent desorption efficiencies, ice stratification, or grain-chemistry selectivity could plausibly erase a metallicity trend. The factor-of-10 band is also too wide to call a strong constraint. I suggest either restricting the conclusion to hot-core data, where the desorption
  2. [Abstract; §3.1.1; §3.2.2; Summary Point 3] The central thesis 'TMC-1 CP and L1544 are not outliers but representative laboratories' is not established by the evidence cited. The paper itself explains why these sources were chosen: TMC-1 CP is the cyanopolyyne peak and has four line-of-sight/velocity components whose overlap 'increases the line intensities, enabling the detection of many molecules' (§3.1.1); L1544 is the prototypical prestellar core, and only ~40 of 1746 starless cores meet the density threshold used to identify such objects (§3.2.2). The comparative data show real core-to-core scatter — CH3CHO in 70% of Taurus but 50% of Perseus cores, larger COMs in ~20% of the Perseus subset, and L1544 chemically richer than L1498/L1517B (§3.2.4). These data support the claim that many molecules are widespread, but not that two deliberately selected extreme sources are statistically representative. If 'representative' is intend
  3. [§5.1 and Fig. 9] The comparison of chemical inventories between TMC-1 CP and G+0.693 uses pie charts based on the number of detected species per chemical family. Detection counts depend critically on survey sensitivity, beam size, line widths, excitation temperatures, line confusion, and analysis methods. The statement that 'the production of O-bearing molecules is favoured' in G+0.693, because 25% of detected species are O-bearing versus 13% in TMC-1 CP, therefore does not directly measure relative production efficiency; it may partly reflect the different spectral surveys and physical conditions. The caption should state this limitation explicitly, or the analysis should be supplemented by abundance-based ratios for common molecules rather than raw species counts.
minor comments (5)
  1. [Supplemental Text, Abstract] The Supplemental Text abstract contains the placeholder line 'Keywords keywords, separated by comma, no full stop, lowercase'. This must be replaced with actual keywords.
  2. [§3.2.4] Typo: 'COMs were threfore thought' should read 'therefore'.
  3. [§2.2] Typo: 'observed in the the shocked region' has a duplicated 'the'.
  4. [§6] Typo: 'another low-metalicity environment' should be 'low-metallicity'. Also in the same paragraph, 'CH3OH formation may be inhibited' is consistent with §4.3, but the preceding sentence about the Outer Galaxy would benefit from a pointer to Fig. 10.
  5. [Fig. 10] Fig. 10 would be more useful with error bars, upper/lower limit markers, and a note on whether any ratios involve optically thick lines. The current presentation makes the 'factor of 10' statement hard to evaluate quantitatively.

Circularity Check

1 steps flagged

Local circularity in §5.2 metallicity argument; central review synthesis otherwise self-contained.

specific steps
  1. other [§5.2 (Figure 10, paragraph beginning 'We note that the dominant desorption mechanisms...')]
    "We assume that desorption efficiencies are broadly similar among COMs, supported by the absence of systematic differences in COM/CH3OH ratios between hot cores and starless objects. Figure 10 shows that the majority of the ratios lie within a factor of 10, which suggests that the COM production efficiency is not significantly affected by metallicity."

    The premise used to convert the observable COM/CH3OH ratio into a claim about production efficiency is itself inferred from the same observed ratio pattern that the conclusion explains. If desorption efficiencies were species-dependent, the flat ratios would reflect desorption physics—thermal sublimation in hot cores versus reactive/cosmic-ray desorption in TMC-1 CP and L1544—rather than COM production. The 'absence of systematic differences' between hot cores and starless objects is not an independent calibration; it is drawn from the same Fig. 10 ratio scatter whose flatness is then interpreted as metallicity-independent production. The conclusion therefore depends on an assumption whose only cited support is the very phenomenon under interpretation.

full rationale

Most of this manuscript is a literature synthesis with no fitted parameters or first-principles derivations, so the classic prediction-reduces-to-fit circularity is absent. The central claim that TMC-1 CP and L1544 are representative laboratories is an interpretive statement, not a derived result. It may be over-strong—the paper itself notes that TMC-1 CP's overlapping velocity components 'increase the line intensities, enabling the detection of many molecules' and that L1544 was selected as an extreme prestellar core—but that is a selection-bias/under-support concern, not a circularity. Self-citations are abundant in this review but are normal and are not used as an unverified uniqueness theorem or ansatz. The one genuinely circular step is in §5.2: the desorption-efficiency assumption is justified by the absence of systematic COM/CH3OH ratio differences between hot cores and starless objects, and then the same ratio flatness (within a factor of 10) is used to conclude that COM production efficiency is metallicity-independent. Because the sources in Fig. 10 span different desorption regimes, the flat ratios could equally reflect species-specific desorption efficiencies; the argument lacks an independent calibration of desorption. This is a local, acknowledged limitation of the metallicity synthesis, not a defect in the review's entire derivation chain, so a moderate score is appropriate.

Axiom & Free-Parameter Ledger

0 free parameters · 4 axioms · 0 invented entities

No free parameters are fitted in this review: numeric inputs (metallicity labels in Fig 10, grain parameters in Eq 1, cosmic-ray ionization rates in §2.3.3) are adopted from the cited literature, and the paper performs no regression or model fit to the claims it advances. The load-bearing assumptions are the four listed domain/ad hoc premises about reaction networks, gas-to-dust scaling, cross-survey comparability, and the N2H+ proxy. No invented entities: candidate reservoirs such as ammonium salts (NH4SH) and sulfur allotropes (S2, S8) are cited hypotheses from prior literature, and the review explicitly concludes the S and P reservoirs remain unknown.

axioms (4)
  • domain assumption Chemical reaction network models (UMIST/KIDA) with thousands of largely estimated reactions are representative vehicles for interpreting observed abundances
    §2.3 uses pseudo-time-dependent network models as the interpretive frame; the review itself documents under-prediction of aromatics by several orders of magnitude and of S-species by ≥1 order (§3.1.1.5, §3.1.4), so the assumption is load-bearing but imperfect.
  • domain assumption Gas-to-dust mass ratio scales linearly with metallicity, so dust-derived hydrogen column densities are valid in the LMC/SMC and outer Galaxy
    §4.3 explicitly notes the systematic uncertainty this introduces; molecular abundances relative to H in low-metallicity environments inherit this scaling.
  • ad hoc to paper Cross-source abundance and detection-rate comparisons are unbiased despite heterogeneous sensitivity, beam size, and analysis methods
    The representativeness claim of Summary Point 3 and the Fig 10 metallicity comparison pool surveys of very different depth (sub-mK rms, 1000-hour integrations at TMC-1 CP vs shorter surveys elsewhere) and methods (single-dish vs interferometric); the review does not quantify survey-selection effects.
  • domain assumption N2 abundance and hence the nitrogen budget can be inferred from N2H+ observations
    Adopted in §2.2 to establish major N reservoirs; N2 itself is unobservable in dark clouds, so the proxy relationship carries the reservoir estimate.

pith-pipeline@v1.3.0-alltime-deepseek · 61798 in / 19462 out tokens · 197438 ms · 2026-08-01T02:12:23.335857+00:00 · methodology

0 comments
read the original abstract

Recent molecular line surveys, particularly toward the starless core TMC-1 CP, have greatly expanded the inventory of interstellar molecules, revealing numerous isomers and even aromatic species. Their diverse formation pathways---from ion-molecule reactions to the possible fragmentation of carbonaceous grains---remain under debate, linking chemistry to the life cycle of the interstellar medium. Simple tracers such as carbon chains and deuterated ions are used to probe the physical conditions and evolutionary state of nearby filaments and cores, as well as in massive infrared dark clouds. Ice chemistry has also entered a new era with JWST: spatial distributions of ices indicate a connection between catastrophic freeze-out, established in the prestellar core L1544, and formation of complex organic molecules. Overall, TMC-1 CP and L1544 are not outliers but representative laboratories of molecular cloud physics and chemistry. Extending these findings across diverse environments, from the Central Molecular Zone to low-metallicity galaxies, is essential for a unified picture of how interstellar chemistry regulates the path from clouds to stars and planets.

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

300 extracted references · 30 canonical work pages · 2 internal anchors

  1. [1]

    Acevedo O, Fitzjarrald D. 2001. J. Atmos. Sci. 58:2650--67

    2001

  2. [2]

    Agric. For. Meteorol. 149:1--10

  3. [3]

    Baas P, Steeneveld G, van de Weil B, Holtslag A. 2006. J. Atmos. Sci. 63:3045--54

    2006

  4. [4]

    Badran F, Thiria S, Crepon M. 1991. J. Geophys. Res. 96:20,521--29

    1991

  5. [5]

    Bakas NA, Ioannou PJ. 2007. J. Atmos. Sci. 64:1509--29

    2007

  6. [6]

    Calanca P, Forrer J, Rotach M. 1998. Q. J. R. Meteorol. Soc. 124:1--18

    1998

  7. [7]

    D'Asaro EA, Lien RC. 2000. J. Phys. Oceanog. 30:123--45

    2000

  8. [8]

    de Silva I, Fernando H, Eaton F, Hebert D. 1996. Earth Planetary Sci. Let. 143:217--31

    1996

  9. [9]

    , keywords =

    Classification of Filament Formation Mechanisms in Magnetized Molecular Clouds. , keywords =. doi:10.3847/1538-4357/ac07a1 , archivePrefix =. 2012.02205 , primaryClass =

    Pith/arXiv arXiv 2012

  10. [10]

    , keywords =

    Molecular Development in the Large Magellanic Cloud. , keywords =. doi:10.1088/0004-637X/812/2/142 , adsurl =

    work page doi:10.1088/0004-637x/812/2/142

  11. [11]

    , keywords =

    Simulations of the Chemistry in the Small Magellanic Cloud. , keywords =. doi:10.3847/0004-637X/822/2/105 , adsurl =

    work page doi:10.3847/0004-637x/822/2/105

  12. [12]

    , keywords =

    Hot Cores in Magellanic Clouds. , keywords =. doi:10.3847/1538-4357/aabaf2 , adsurl =

    work page doi:10.3847/1538-4357/aabaf2

  13. [13]

    , keywords =

    Millimeter-wave Observations of CN and HNC and Their ^ 15 N Isotopologues: A New Evaluation of the ^ 14 N/ ^ 15 N Ratio across the Galaxy. , keywords =. doi:10.1088/0004-637X/744/2/194 , adsurl =

    work page doi:10.1088/0004-637x/744/2/194

  14. [14]

    Chemical Reviews , keywords =

    Chemistry of Dark Clouds: Databases, Networks, and Models. Chemical Reviews , keywords =. doi:10.1021/cr4001176 , archivePrefix =. 1310.3651 , primaryClass =

    Pith/arXiv arXiv

  15. [15]

    , keywords =

    O-bearing complex organic molecules at the cyanopolyyne peak of TMC-1: Detection of C _ 2 H _ 3 CHO, C _ 2 H _ 3 OH, HCOOCH _ 3 , and CH _ 3 OCH _ 3. , keywords =. doi:10.1051/0004-6361/202140978 , archivePrefix =. 2104.11506 , primaryClass =

    Pith/arXiv arXiv

  16. [16]

    , keywords =

    Discovery of the propargyl radical (CH _ 2 CCH) in TMC-1: One of the most abundant radicals ever found and a key species for cyclization to benzene in cold dark clouds. , keywords =. doi:10.1051/0004-6361/202140553 , archivePrefix =. 2103.03807 , primaryClass =

    Pith/arXiv arXiv

  17. [17]

    , keywords =

    A new protonated molecule discovered in TMC-1: HCCNCH ^ +. , keywords =. doi:10.1051/0004-6361/202243396 , archivePrefix =. 2203.06999 , primaryClass =

    Pith/arXiv arXiv

  18. [18]

    , keywords =

    Discovery of interstellar NC _ 4 NH ^ + : Dicyanopolyynes are indeed abundant in space. , keywords =. doi:10.1051/0004-6361/202245492 , archivePrefix =. 2212.06903 , primaryClass =

    Pith/arXiv arXiv

  19. [19]

    , keywords =

    The chemistry of H _ 2 NC in the interstellar medium and the role of the C + NH _ 3 reaction. , keywords =. doi:10.1051/0004-6361/202346279 , archivePrefix =. 2303.12011 , primaryClass =

    Pith/arXiv arXiv

  20. [20]

    , keywords =

    Detection of ethanol, acetone, and propanal in TMC-1 New O-bearing complex organics in cold sources. , keywords =. doi:10.1051/0004-6361/202346076 , archivePrefix =. 2303.16121 , primaryClass =

    Pith/arXiv arXiv

  21. [21]

    , keywords =

    Abundance and excitation of molecular anions in interstellar clouds. , keywords =. doi:10.1051/0004-6361/202347077 , archivePrefix =. 2307.04487 , primaryClass =

    Pith/arXiv arXiv

  22. [22]

    , keywords =

    Aromatic cycles are widespread in cold clouds. , keywords =. doi:10.1051/0004-6361/202347524 , archivePrefix =. 2308.15951 , primaryClass =

    Pith/arXiv arXiv

  23. [23]

    , keywords =

    The rich interstellar reservoir of dinitriles: Detection of malononitrile and maleonitrile in TMC-1. , keywords =. doi:10.1051/0004-6361/202451525 , archivePrefix =. 2408.02843 , primaryClass =

    Pith/arXiv arXiv

  24. [24]

    , keywords =

    Detection of thioacetaldehyde (CH _ 3 CHS) in TMC-1: Sulfur-oxygen differentiation along the hydrogenation sequence. , keywords =. doi:10.1051/0004-6361/202453459 , archivePrefix =. 2501.05125 , primaryClass =

    Pith/arXiv arXiv

  25. [25]

    , keywords =

    A search for the three isomers of cyano-1,3-butadiene in TMC-1: Implications for bottom-up routes involving 1,3-butadiene. , keywords =. doi:10.1051/0004-6361/202554343 , archivePrefix =. 2503.23841 , primaryClass =

    Pith/arXiv arXiv

  26. [26]

    ACS Earth and Space Chemistry , keywords =

    TMC-1: Probing the Onset of Chemical Complexity in Space. ACS Earth and Space Chemistry , keywords =. doi:10.1021/acsearthspacechem.6c00026 , archivePrefix =. 2604.26439 , primaryClass =

    Pith/arXiv arXiv

  27. [27]

    Molecular Evolution in Collapsing Prestellar Cores. II. The Effect of Grain-Surface Reactions. , keywords =. doi:10.1086/376616 , archivePrefix =. astro-ph/0305054 , primaryClass =

    Pith/arXiv arXiv

  28. [28]

    Molecular Evolution in Collapsing Prestellar Cores. III. Contraction of a Bonnor-Ebert Sphere. , keywords =. doi:10.1086/427017 , archivePrefix =. astro-ph/0410582 , primaryClass =

    Pith/arXiv arXiv

  29. [29]

    From Prestellar to Protostellar Cores. II. Time Dependence and Deuterium Fractionation. , keywords =. doi:10.1088/0004-637X/760/1/40 , archivePrefix =. 1210.2476 , primaryClass =

    Pith/arXiv arXiv

  30. [30]

    Molecules with ALMA at Planet-forming Scales (MAPS). XIII. HCO ^ + and Disk Ionization Structure. , keywords =. doi:10.3847/1538-4365/ac143c , archivePrefix =. 2109.06419 , primaryClass =

    Pith/arXiv arXiv

  31. [31]

    Comets III , year = 2024, editor =

    The Physical and Chemical Processes in Protoplanetary Disks: Constraints on the Composition of Comets. Comets III , year = 2024, editor =. doi:10.2458/azu_uapress_9780816553631-ch002 , adsurl =

    work page doi:10.2458/azu_uapress_9780816553631-ch002 2024

  32. [32]

    , keywords =

    Laboratory spectroscopy of allylimine and tentative detection towards the G+0.693-0.027 molecular cloud. , keywords =. doi:10.1051/0004-6361/202244618 , adsurl =

    work page doi:10.1051/0004-6361/202244618

  33. [33]

    Chemie der Erde / Geochemistry , year = 2017, month = may, volume =

    The nature, origin and modification of insoluble organic matter in chondrites, the major source of Earth's C and N. Chemie der Erde / Geochemistry , year = 2017, month = may, volume =. doi:10.1016/j.chemer.2017.01.007 , adsurl =

    doi:10.1016/j.chemer.2017.01.007 2017

  34. [34]

    , keywords =

    A Case of Simultaneous Star and Planet Formation. , keywords =. doi:10.3847/2041-8213/abc550 , archivePrefix =. 2010.15135 , primaryClass =

    Pith/arXiv arXiv 2041

  35. [35]

    , keywords =

    Cometary Chemistry and the Origin of Icy Solar System Bodies: The View After Rosetta. , keywords =. doi:10.1146/annurev-astro-091918-104409 , archivePrefix =. 1908.04046 , primaryClass =

    Pith/arXiv arXiv 1908

  36. [36]

    , keywords =

    Abundant ammonium hydrosulphide embedded in cometary dust grains. , keywords =. doi:10.1093/mnras/stac2440 , archivePrefix =. 2208.11396 , primaryClass =

    Pith/arXiv arXiv

  37. [37]

    , keywords =

    From filamentary clouds to prestellar cores to the stellar IMF: Initial highlights from the Herschel Gould Belt Survey. , keywords =. doi:10.1051/0004-6361/201014666 , archivePrefix =. 1005.2618 , primaryClass =

    Pith/arXiv arXiv

  38. [38]

    Protostars and Planets VI , year = 2014, editor =

    From Filamentary Networks to Dense Cores in Molecular Clouds: Toward a New Paradigm for Star Formation. Protostars and Planets VI , year = 2014, editor =. doi:10.2458/azu_uapress_9780816531240-ch002 , archivePrefix =. 1312.6232 , primaryClass =

    Pith/arXiv arXiv 2014

  39. [39]

    , keywords =

    Precise Observations of the ^ 12 C/ ^ 13 C Ratios of HC _ 3 N in the Low-mass Star-forming Region L1527. , keywords =. doi:10.3847/1538-4357/833/2/291 , archivePrefix =. 1610.02793 , primaryClass =

    Pith/arXiv arXiv

  40. [40]

    Nature Astronomy , year = 2026, month = mar, volume =

    A detection of sulfur-bearing cyclic hydrocarbons in space. Nature Astronomy , year = 2026, month = mar, volume =. doi:10.1038/s41550-025-02749-7 , adsurl =

    doi:10.1038/s41550-025-02749-7 2026

  41. [41]

    , keywords =

    Complex Molecules in the L1157 Molecular Outflow. , keywords =. doi:10.1086/590110 , archivePrefix =. 0805.2550 , primaryClass =

    Pith/arXiv arXiv

  42. [42]

    , keywords =

    Probing the ion-neutral drift velocity toward the L1544 prestellar core: Detection of ambipolar diffusion using N _ 2 D ^ + and para-NH _ 2 D. , keywords =. doi:10.1051/0004-6361/202658871 , archivePrefix =. 2605.22541 , primaryClass =

    Pith/arXiv arXiv

  43. [43]

    , keywords =

    The chemical make-up of the Sun: A 2020 vision. , keywords =. doi:10.1051/0004-6361/202140445 , archivePrefix =. 2105.01661 , primaryClass =

    Pith/arXiv arXiv 2020

  44. [44]

    , keywords =

    CO Depletion and Deuterium Fractionation in Prestellar Cores. , keywords =. doi:10.1086/374263 , archivePrefix =. astro-ph/0301651 , primaryClass =

    Pith/arXiv arXiv

  45. [45]

    , keywords =

    Detection of complex organic molecules in a prestellar core: a new challenge for astrochemical models. , keywords =. doi:10.1051/0004-6361/201219207 , adsurl =

    doi:10.1051/0004-6361/201219207

  46. [46]

    , keywords =

    Isotope-selective photodestruction of carbon monoxide. , keywords =. doi:10.1086/159812 , adsurl =

    work page doi:10.1086/159812

  47. [47]

    , keywords =

    Formation of complex organic molecules in cold objects: the role of gas-phase reactions. , keywords =. doi:10.1093/mnrasl/slv009 , archivePrefix =. 1501.03668 , primaryClass =

    Pith/arXiv arXiv

  48. [48]

    , keywords =

    Widespread deuteration across the IRDC G035.39-00.33. , keywords =. doi:10.1093/mnras/stw403 , archivePrefix =. 1602.06798 , primaryClass =

    Pith/arXiv arXiv

  49. [49]

    , keywords =

    ALMA-IRDC: dense gas mass distribution from cloud to core scales. , keywords =. doi:10.1093/mnras/stab803 , archivePrefix =. 2103.09122 , primaryClass =

    Pith/arXiv arXiv

  50. [50]

    , keywords =

    PHANGS-JWST First Results: Multiwavelength View of Feedback-driven Bubbles (the Phantom Voids) across NGC 628. , keywords =. doi:10.3847/2041-8213/aca7b9 , archivePrefix =. 2212.00812 , primaryClass =

    Pith/arXiv arXiv 2041

  51. [51]

    A massive, quiescent core in the dragon cloud (IRDC G028.37+00.07)

    Mother of dragons. A massive, quiescent core in the dragon cloud (IRDC G028.37+00.07). , keywords =. doi:10.1051/0004-6361/202245668 , archivePrefix =. 2303.15499 , primaryClass =

    Pith/arXiv arXiv

  52. [52]

    3D CMZ. I. Central Molecular Zone Overview. , keywords =. doi:10.3847/1538-4357/adb5f0 , archivePrefix =. 2410.17334 , primaryClass =

    Pith/arXiv arXiv

  53. [53]

    Science , keywords =

    Unified prebiotically plausible synthesis of pyrimidine and purine RNA ribonucleotides. Science , keywords =. doi:10.1126/science.aax2747 , adsurl =

    work page doi:10.1126/science.aax2747

  54. [54]

    , keywords =

    Detection of HC11N in the cold dust cloud TMC-1. , keywords =. doi:10.1086/184460 , adsurl =

    work page doi:10.1086/184460

  55. [55]

    , keywords =

    A Survey for Dense Cores in Dark Clouds. , keywords =. doi:10.1086/191365 , adsurl =

    doi:10.1086/191365

  56. [56]

    , keywords =

    N _ 2 H ^ + and C ^ 18 O Depletion in a Cold Dark Cloud. , keywords =. doi:10.1086/340950 , archivePrefix =. astro-ph/0204016 , primaryClass =

    Pith/arXiv arXiv

  57. [57]

    , keywords =

    Molecular Cloud Formation behind Shock Waves. , keywords =. doi:10.1086/422578 , archivePrefix =. astro-ph/0405329 , primaryClass =

    Pith/arXiv arXiv

  58. [58]

    , keywords =

    Cold Dark Clouds: The Initial Conditions for Star Formation. , keywords =. doi:10.1146/annurev.astro.45.071206.100404 , archivePrefix =. 0705.3765 , primaryClass =

    arXiv

  59. [59]

    , keywords =

    Methanol at the Edge of the Galaxy: New Observations to Constrain the Galactic Habitable Zone. , keywords =. doi:10.3847/1538-4357/ac27a6 , adsurl =

    doi:10.3847/1538-4357/ac27a6

  60. [60]

    , keywords =

    The Formation of Large Hydrocarbons and Carbon Clusters in Dense Interstellar Clouds. , keywords =. doi:10.1086/303834 , adsurl =

    work page doi:10.1086/303834

  61. [61]

    Survey overview and data release 1

    The HI/OH/Recombination line survey of the inner Milky Way (THOR). Survey overview and data release 1. , keywords =. doi:10.1051/0004-6361/201629143 , archivePrefix =. 1609.03329 , primaryClass =

    Pith/arXiv arXiv

  62. [62]

    , keywords =

    Star Formation from Low to High Mass: A Comparative View. , keywords =. doi:10.1146/annurev-astro-013125-122023 , archivePrefix =. 2501.16866 , primaryClass =

    Pith/arXiv arXiv

  63. [63]

    , keywords =

    The Per-Tau Shell: A Giant Star-forming Spherical Shell Revealed by 3D Dust Observations. , keywords =. doi:10.3847/2041-8213/ac1f95 , archivePrefix =. 2109.09763 , primaryClass =

    Pith/arXiv arXiv 2041

  64. [64]

    , keywords =

    Ethanolamine ices: Experiments in simulated space conditions. , keywords =. doi:10.1051/0004-6361/202450013 , adsurl =

    work page doi:10.1051/0004-6361/202450013

  65. [65]

    , keywords =

    Cyanopolyyne Chemistry in the L1544 Prestellar Core: New Insights from GBT Observations. , keywords =. doi:10.3847/1538-4357/acb5e8 , archivePrefix =. 2301.10106 , primaryClass =

    Pith/arXiv arXiv

  66. [66]

    , keywords =

    Understanding the kinematics of Galactic Centre gas. , keywords =. doi:10.1093/mnras/252.2.210 , adsurl =

    doi:10.1093/mnras/252.2.210

  67. [67]

    , keywords =

    Detection of ^ 15 NNH ^ + in L1544: non-LTE modelling of dyazenilium hyperfine line emission and accurate ^ 14 N/ ^ 15 N values. , keywords =. doi:10.1051/0004-6361/201321276 , archivePrefix =. 1306.0465 , primaryClass =

    Pith/arXiv arXiv

  68. [68]

    , keywords =

    Deuterated methanol in the pre-stellar core L1544. , keywords =. doi:10.1051/0004-6361/201423858 , archivePrefix =. 1408.2491 , primaryClass =

    Pith/arXiv arXiv

  69. [69]

    , keywords =

    Propargylimine in the laboratory and in space: millimetre-wave spectroscopy and its first detection in the ISM. , keywords =. doi:10.1051/0004-6361/202038083 , archivePrefix =. 2006.08401 , primaryClass =

    Pith/arXiv arXiv 2006

  70. [70]

    , keywords =

    Molecular Abundances in OMC-1: The Chemical Composition of Interstellar Molecular Clouds and the Influence of Massive Star Formation. , keywords =. doi:10.1086/165165 , adsurl =

    doi:10.1086/165165

  71. [71]

    and Ballesteros, Bernabé and Agúndez, Marcelino and Canosa, André and Albaladejo, José and Cernicharo, José and Jiménez, Elena

    Blázquez, Sergio and González, Daniel and Neeman, Elias M. and Ballesteros, Bernabé and Agúndez, Marcelino and Canosa, André and Albaladejo, José and Cernicharo, José and Jiménez, Elena. Gas-phase kinetics of CH3CHO with OH radicals between 11.7 and 177.5 K. Phys. Chem. Chem. Phys. 2020. doi:10.1039/D0CP03203D

    work page doi:10.1039/d0cp03203d 2020

  72. [72]

    , keywords =

    Ice and Dust in the Quiescent Medium of Isolated Dense Cores. , keywords =. doi:10.1088/0004-637X/729/2/92 , archivePrefix =. 1101.2486 , primaryClass =

    Pith/arXiv arXiv

  73. [73]

    , keywords =

    Observations of the icy universe. , keywords =. doi:10.1146/annurev-astro-082214-122348 , archivePrefix =. 1501.05317 , primaryClass =

    Pith/arXiv arXiv

  74. [74]

    , keywords =

    HCNH ^ + abundance in cold dense clouds based on the first hyperfine resolved rate coefficients. , keywords =. doi:10.1051/0004-6361/202348947 , adsurl =

    work page doi:10.1051/0004-6361/202348947

  75. [75]

    , keywords =

    Formation of Complex Organic Molecules in Prestellar Cores: The Role of Nondiffusive Grain Chemistry. , keywords =. doi:10.3847/1538-4357/adea73 , archivePrefix =. 2507.00338 , primaryClass =

    arXiv

  76. [76]

    The Spitzer c2d Survey of Nearby Dense Cores. II. Discovery of a Low-Luminosity Object in the ``Evolved Starless Core'' L1521F. , keywords =. doi:10.1086/508161 , archivePrefix =. astro-ph/0608148 , primaryClass =

    Pith/arXiv arXiv

  77. [77]

    , keywords =

    H _ 2 Ortho-to-para Conversion on Grains: A Route to Fast Deuterium Fractionation in Dense Cloud Cores?. , keywords =. doi:10.3847/2041-8213/aa95b7 , archivePrefix =. 1708.02046 , primaryClass =

    Pith/arXiv arXiv 2041

  78. [78]

    , keywords =

    A new proxy to estimate the cosmic ray ionization rate in dense cores. , keywords =. doi:10.1093/mnrasl/slaa048 , archivePrefix =. 2003.05416 , primaryClass =

    Pith/arXiv arXiv 2003

  79. [79]

    , keywords =

    Chemical analysis of prestellar cores in Ophiuchus yields short timescales and rapid collapse. , keywords =. doi:10.1051/0004-6361/202141252 , archivePrefix =. 2105.02253 , primaryClass =

    Pith/arXiv arXiv

  80. [80]

    , year = 2014, month = dec, volume =

    H _ 2 D ^ + observations give an age of at least one million years for a cloud core forming Sun-like stars. , year = 2014, month = dec, volume =. doi:10.1038/nature13924 , adsurl =

    doi:10.1038/nature13924 2014

Showing first 80 references.