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arxiv: 2606.21878 · v1 · pith:ITCIRKKVnew · submitted 2026-06-20 · 🌌 astro-ph.SR

The efficiency per free-fall time as a ratio of the Star Formation Rate to the gas-infall rate in collapsing cores: dependence on the core definition, accretion, and radial structure

Fabi\'an Quesada-Z\'u\~niga , Manuel Zamora-Avil\'es , Enrique V\'azquez-Semadeni , Gilberto C. G\'omez , Aina Palau , Javier Ballesteros-Paredes This is my paper

Pith reviewed 2026-06-26 11:50 UTC · model grok-4.3

classification 🌌 astro-ph.SR
keywords efficiency per free-fall timestar formation ratemolecular cloud coresgravitational collapsenumerical simulationsgas accretioncore definition
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The pith

The efficiency per free-fall time in collapsing cores depends sensitively on core definition and external gas supply.

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

The paper examines the quantity called efficiency per free-fall time, which is formally the ratio of the star formation rate to the gas-infall rate into a core. It performs simulations of isolated core collapse with different initial densities and with closed or open boundaries that control whether fresh gas can enter. The measured value changes with the density threshold chosen to mark the core edge and with whether mass can accrete from outside. This matters because the quantity is used to characterize star formation activity in molecular clouds, so its dependence on these choices affects how simulation results and observations are compared.

Core claim

In simulations that begin with a central Gaussian overdensity and evolve toward a density profile n proportional to r to the minus two, a sink forms at the center. After sink formation the efficiency per free-fall time rises and then stays relatively stable while accretion continues to replenish core mass, but increases once the reservoir is exhausted. The value is higher in low-mass cores because the larger infall rates onto high-mass cores offset their higher star formation rates. Both the boundary conditions and the density threshold used to define the core alter the inferred efficiency.

What carries the argument

The ratio defined as average star formation rate divided by (core mass divided by free-fall time), where core mass is the gas mass above a chosen density threshold.

If this is right

  • After a sink particle forms, the efficiency per free-fall time becomes stable during ongoing accretion but rises sharply once the gas reservoir is depleted.
  • Low-density cores are more sensitive to boundary conditions than high-density cores because they have smaller mass reservoirs.
  • The efficiency per free-fall time ends up higher in low-mass cores than in high-mass cores because higher infall rates onto the latter compensate for their higher star formation rates.
  • Changing the density threshold that defines the core directly changes the measured core mass and therefore the inferred efficiency.

Where Pith is reading between the lines

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

  • Observed differences in efficiency per free-fall time between cores could partly reflect differences in how the cores are bounded or supplied rather than differences in intrinsic star formation physics.
  • The power-law radial structure that develops during collapse directly sets the infall rate entering the efficiency calculation, so any process that alters that structure would change the measured value.

Load-bearing premise

That defining the core as all gas above a density threshold in simplified isolated simulations with Gaussian initial overdensity captures the physics needed to measure the efficiency in real molecular cloud cores.

What would settle it

Measuring the efficiency in a set of simulations that vary only the density threshold while keeping all other parameters fixed and checking whether the predicted change in the ratio matches the change seen when the same threshold variation is applied to observed core samples with independent accretion-rate estimates.

Figures

Figures reproduced from arXiv: 2606.21878 by Aina Palau, Enrique V\'azquez-Semadeni, Fabi\'an Quesada-Z\'u\~niga, Gilberto C. G\'omez, Javier Ballesteros-Paredes, Manuel Zamora-Avil\'es.

Figure 1
Figure 1. Figure 1: The density profile (measured as the mean density in thin annuli at each radius) for each simulation is presented, highlighting five different moments in time: one immediately after sink formation (green dot-dashed lines), along with two time points preceding and two following this time. Each panel shows an 𝑟 −2 profile (solid black line), with a dashed horizontal line indicating the threshold number densi… view at source ↗
Figure 2
Figure 2. Figure 2: Evolution of the star formation rate (𝑀¤ ★) for each simulation, which is represented with different colors: red for the C100 simulation, green for the O100 simulation, blue for the C1000 simulation and black for the O1000 simulation. stable even for the lowest density threshold, yielding SFE values of SFE ≲ 0.4. For the highest threshold (𝑛thr = 105 cm−3 ), the core became more compact and its mass became… view at source ↗
Figure 3
Figure 3. Figure 3: Core mass and SFE evolution (left and right vertical labels, respectively) for each simulation. Here, we show three different core definitions as follows: the core with 𝑛thr = 103 cm−3 with dotted lines, the core with 𝑛thr = 104 cm−3 with dashed lines, and the core with 𝑛thr = 105 cm−3 with solid lines . The top left panel corresponds to the simulation labeled as C100, the top right panel to O100, the bott… view at source ↗
Figure 4
Figure 4. Figure 4: Evolution of the ratio of the SFR to the gas-infall rate (𝜖ff) for each simulation. As in [PITH_FULL_IMAGE:figures/full_fig_p007_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Profiles of the ratio of the SFR to the gas-infall rate (𝜖ff) for each simulation. The top left panel corresponds to the simulation labeled as C100, the top right panel to O100, the bottom left panel to the C1000, and the bottom right panel to the O1000. The dotted colored lines depict the expected slopes for the indicated values of the density-profile slope, 𝑝. ous times in each simulation, as resulting f… view at source ↗
read the original abstract

A parameter used to characterise star formation activity in MCs is the efficiency per free-fall time, $\epsilon_{\rm ff}$, although commonly referred to as an efficiency, it is formally the ratio between the star formation rate (SFR) and the gas-infall rate. Here we numerically study the collapse of cores and define $\epsilon_{\rm ff}\equiv\langle\dot{M}_\star\rangle/(M_{\rm core}/\tau_{\rm ff})$, where $\langle\dot{M}_\star\rangle$ is the average SFR, $M_{\rm core}$ is the gas mass within the core (as the gas cells above a density threshold), and $\tau_{\rm ff}$ is the free-fall time of the core gas. We perform simplified numerical experiments of the gravitational collapse of an isolated core, varying the initial mean number density ($n_0=100$ and $1000~\rm cm^{-3}$) and adopting closed/open BCs to (dis)allow fresh gas accretion into the domain. The simulations start with a slight central Gaussian overdensity that evolved into a power-law profile, $n\propto r^{-p}$ with $p\to2$. As the collapse proceeds, a sink particle forms in the center of the core. We find that both the BCs and the adopted core definition modify the measured core properties and, consequently, the inferred $\epsilon_{\rm ff}$. Low-density models have less mass available, and their accretion histories are therefore much more sensitive to the choice of BCs, while high-density runs, with their larger mass reservoirs, maintain similar accretion histories regardless of the BCs. In all models, after sink formation, $\epsilon_{\rm ff}$ rises and then remains relatively stable while accretion continues to replenish the core's mass, but increases once the gas reservoir is exhausted. Somewhat counterintuitively, $\epsilon_{\rm ff}$ is higher in the low-mass cores, since the larger gas infall rates onto the high-mass cores compensate for their higher SFR. We conclude that the inferred $\epsilon_{\rm ff}$ depends sensitively on both the adopted core definition and external mass supply

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript reports controlled numerical experiments on the gravitational collapse of isolated cores initialized with a central Gaussian overdensity that evolves to a power-law density profile. It defines ε_ff ≡ ⟨Ṁ⋆⟩ / (M_core / τ_ff), where M_core is the mass of gas cells above a chosen density threshold, and examines how the measured ε_ff responds to initial mean density (n0 = 100 or 1000 cm^{-3}), closed versus open boundary conditions, and the density threshold adopted for the core. The central result is that ε_ff depends sensitively on both the core definition and the presence of external mass supply, with higher values found in lower-mass cores because their lower infall rates are not offset by proportionally lower SFRs.

Significance. If the reported sensitivities hold, the work supplies a concrete, internally consistent demonstration that ε_ff inferred from simulations is not robust to standard modeling choices. This is useful for the field because it supplies a controlled test of how core definition and mass reservoir affect the ratio of SFR to gas-infall rate, directly addressing a quantity widely used to compare simulations and observations. The use of clearly defined, reproducible numerical setups with no free parameters fitted to data is a methodological strength.

major comments (2)
  1. [Abstract / Results] Abstract and results section: the claim that ε_ff is higher in low-mass cores because 'larger gas infall rates onto the high-mass cores compensate for their higher SFR' is the key counter-intuitive result; however, the manuscript does not report the actual numerical values of ⟨Ṁ⋆⟩, M_core, and τ_ff (or their ratios) for the different n0 and BC cases, making it impossible to verify the magnitude of the compensation or to judge whether the difference is statistically significant given the sink-particle accretion implementation.
  2. [Methods] Methods: the core is defined as all gas cells above a chosen density threshold, yet the specific threshold values, the resulting M_core(threshold) curves, and the time evolution of the enclosed mass are not tabulated or plotted; without these data the statement that 'both the BCs and the adopted core definition modify the measured core properties' cannot be assessed quantitatively.
minor comments (2)
  1. [Results] The evolution of the density profile to n ∝ r^{-p} with p → 2 is stated but not illustrated; a figure showing radial profiles at several times before and after sink formation would clarify how the power-law index is measured and whether it is the same across the n0 and BC runs.
  2. [Abstract / Methods] Notation: the symbol ⟨Ṁ⋆⟩ is introduced as an average SFR, but the time window over which the average is taken (e.g., from sink formation to a fixed multiple of τ_ff) is not stated explicitly.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive review and recommendation of minor revision. We address each major comment below.

read point-by-point responses

  1. Referee: [Abstract / Results] Abstract and results section: the claim that ε_ff is higher in low-mass cores because 'larger gas infall rates onto the high-mass cores compensate for their higher SFR' is the key counter-intuitive result; however, the manuscript does not report the actual numerical values of ⟨Ṁ⋆⟩, M_core, and τ_ff (or their ratios) for the different n0 and BC cases, making it impossible to verify the magnitude of the compensation or to judge whether the difference is statistically significant given the sink-particle accretion implementation.

    Authors: We agree that explicit numerical values are needed to substantiate the compensation claim. The revised manuscript will add a table reporting the time-averaged ⟨Ṁ⋆⟩, M_core, τ_ff and resulting ε_ff (with standard deviations) for every n0–BC combination. This will permit direct verification of the magnitude of the effect and assessment of its robustness given the sink implementation. revision: yes

  2. Referee: [Methods] Methods: the core is defined as all gas cells above a chosen density threshold, yet the specific threshold values, the resulting M_core(threshold) curves, and the time evolution of the enclosed mass are not tabulated or plotted; without these data the statement that 'both the BCs and the adopted core definition modify the measured core properties' cannot be assessed quantitatively.

    Authors: We acknowledge that quantitative support for the sensitivity to core definition is currently insufficient. The revision will include (i) explicit statement of the density thresholds used in each model and (ii) a new figure displaying M_core versus threshold at representative times together with the time evolution of enclosed mass for the adopted thresholds under both boundary conditions. revision: yes

Circularity Check

0 steps flagged

No significant circularity

full rationale

The paper performs numerical hydrodynamical experiments of isolated core collapse under varying initial densities and boundary conditions, then directly computes ε_ff from the simulation outputs using the explicit definition ε_ff ≡ ⟨Ṁ_star⟩ / (M_core / τ_ff), where all quantities are measured quantities extracted from the runs. The reported sensitivity of ε_ff to core density-threshold definition and to open/closed boundaries follows immediately from those measurements; no parameter is fitted to data and then re-labeled as a prediction, no uniqueness theorem or ansatz is imported via self-citation, and the central claim is scoped to the internal behavior of the chosen numerical setups rather than asserted as an external physical law. The derivation chain is therefore self-contained and does not reduce to its inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The central claim rests on standard assumptions of self-gravitating hydrodynamics and the free-fall time definition; no new entities or fitted parameters are introduced in the abstract.

axioms (2)
  • domain assumption Gravitational collapse of an isolated core can be modeled with standard hydrodynamics and a sink particle for the central star.
    Invoked throughout the numerical experiments described in the abstract.
  • domain assumption Free-fall time τ_ff is computed from the mean density of gas cells above the chosen threshold.
    Used in the explicit definition of ε_ff.

pith-pipeline@v0.9.1-grok · 5986 in / 1291 out tokens · 15156 ms · 2026-06-26T11:50:18.380079+00:00 · methodology

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Reference graph

Works this paper leans on

93 extracted references · 75 canonical work pages · 27 internal anchors

  1. [1]

    , title =

    Gong, Hao and Ostriker, Eve C. , title =. The Astrophysical Journal , year =

  2. [2]

    and Kim, Chang-Goo and others , title =

    Mao, Saoli and Ostriker, Eve C. and Kim, Chang-Goo and others , title =. The Astrophysical Journal , year =

  3. [3]

    The Astrophysical Journal Supplement Series , archivePrefix = "arXiv", eprint =

    yt: A Multi-code Analysis Toolkit for Astrophysical Simulation Data. The Astrophysical Journal Supplement Series , archivePrefix = "arXiv", eprint =. doi:10.1088/0067-0049/192/1/9 , adsurl =

    work page doi:10.1088/0067-0049/192/1/9

  4. [4]

    , year = 2026, month = jan, volume =

    Comparing the Mgas-Nyso Relation inside a Giant Molecular Cloud. , year = 2026, month = jan, volume =. doi:xxx , adsurl =

    2026

  5. [5]

    Probability distribution function of integrated intensity for dense molecular gas tracers

    ATOMS: ALMA Three-millimeter Observations of massive Star-forming regions - XX. Probability distribution function of integrated intensity for dense molecular gas tracers. , keywords =. doi:10.1093/mnras/staf176 , archivePrefix =. 2501.16682 , primaryClass =

    work page doi:10.1093/mnras/staf176

  6. [6]

    N2H+ depletion in the massive protostellar cluster AFGL 5142

    N _ 2 H ^ + depletion in the massive protostellar cluster AFGL 5142. , keywords =. doi:10.1051/0004-6361/201014152 , archivePrefix =. 1009.2333 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1051/0004-6361/201014152

  7. [7]

    Properties of dense cores in clustered massive star-forming regions at high angular resolution

    Properties of dense cores in clustered massive star-forming regions at high angular resolution. , keywords =. doi:10.1093/mnras/stt679 , archivePrefix =. 1304.5136 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stt679

  8. [8]

    The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers

    The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers. , keywords =. doi:10.1086/680342 , archivePrefix =. 1501.01629 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1086/680342

  9. [9]

    , keywords =

    The ALMA Survey of Star Formation and Evolution in Massive Protoclusters with Blue Profiles (ASSEMBLE): Core Growth, Cluster Contraction, and Primordial Mass Segregation. , keywords =. doi:10.3847/1538-4365/acfee5 , archivePrefix =. 2309.14684 , primaryClass =

    work page doi:10.3847/1538-4365/acfee5

  10. [10]

    , keywords =

    The effect of photoionizing feedback on the shaping of hierarchically-forming stellar clusters. , keywords =. doi:10.1093/mnras/staa2921 , archivePrefix =. 2003.12711 , primaryClass =

    work page doi:10.1093/mnras/staa2921 2003

  11. [11]

    and Bernard, Jean-Philippe and Chu, You-Hua and Fukui, Yasuo and Gruendl, Robert A

    Wong, Tony and Hughes, Annie and Ott, Jürgen and Muller, Erik and Pineda, Jorge L. and Bernard, Jean-Philippe and Chu, You-Hua and Fukui, Yasuo and Gruendl, Robert A. and Henkel, Christian and Kawamura, Akiko and Klein, Ulrich and Looney, Leslie W. and Maddison, Sarah and Mizuno, Yoji and Paradis, Deborah and Seale, Jonathan and , Daniel E. Welty , title ...

    work page doi:10.1088/0067-0049/197/2/16 2011

  12. [12]

    The Star Formation Rate of Supersonic MHD Turbulence

    The Star Formation Rate of Supersonic Magnetohydrodynamic Turbulence. , keywords =. doi:10.1088/0004-637X/730/1/40 , archivePrefix =. 0907.0248 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/0004-637x/730/1/40

  13. [13]

    Analytical star formation rate from gravoturbulent fragmentation

    Analytical Star Formation Rate from Gravoturbulent Fragmentation. , keywords =. doi:10.1088/2041-8205/743/2/L29 , archivePrefix =. 1110.0033 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/2041-8205/743/2/l29 2041

  14. [14]

    , keywords =

    Stellar feedback in the star formation-gas density relation: Comparison between simulations and observations. , keywords =. doi:10.1051/0004-6361/202347527 , archivePrefix =. 2311.18522 , primaryClass =

    work page doi:10.1051/0004-6361/202347527

  15. [15]

    , keywords =

    FLASH: An Adaptive Mesh Hydrodynamics Code for Modeling Astrophysical Thermonuclear Flashes. , keywords =. doi:10.1086/317361 , adsurl =

    work page doi:10.1086/317361

  16. [16]

    Physica Scripta Volume T , year = 2008, month = dec, volume =

    Introduction to FLASH 3.0, with application to supersonic turbulence. Physica Scripta Volume T , year = 2008, month = dec, volume =. doi:10.1088/0031-8949/2008/T132/014046 , adsurl =

    work page doi:10.1088/0031-8949/2008/t132/014046 2008

  17. [18]

    The Schmidt Kennicutt law, the star formation efficiency, and the mass density of clusters from gravitational collapse rather than turbulent support

    Gravity or turbulence? VII. The Schmidt Kennicutt law, the star formation efficiency, and the mass density of clusters from gravitational collapse rather than turbulent support. , keywords =. doi:10.1093/mnras/staf1123 , archivePrefix =. 2409.11588 , primaryClass =

    work page doi:10.1093/mnras/staf1123

  18. [19]

    The physics behind the Kennicutt-Schmidt relation

    Gravity or turbulence? - VI. The physics behind the Kennicutt-Schmidt relation. , keywords =. doi:10.1093/mnras/stae2036 , archivePrefix =. 2408.13636 , primaryClass =

    work page doi:10.1093/mnras/stae2036

  19. [20]

    , year = 1986, month = nov, volume =

    Relationships Between Dense Cores and Young Stars. , year = 1986, month = nov, volume =. doi:10.1086/131882 , adsurl =

    work page doi:10.1086/131882 1986

  20. [21]

    , keywords =

    Star formation in molecular clouds - Observation and theory. , keywords =. doi:10.1146/annurev.aa.25.090187.000323 , adsurl =

    work page doi:10.1146/annurev.aa.25.090187.000323

  21. [22]

    2006 , eprint=

    An Observational Perspective of Low-Mass Dense Cores I: Internal Physical and Chemical Properties , author=. 2006 , eprint=

    2006

  22. [23]

    The nature of the dense core population in the Pipe Nebula: A survey of NH3, CCS, and HC5N molecular line emission

    The Nature of the Dense Core Population in the Pipe Nebula: A Survey of NH _ 3 , CCS, and HC _ 5 N Molecular Line Emission. , keywords =. doi:10.1086/522889 , archivePrefix =. 0708.3660 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1086/522889

  23. [24]

    , keywords =

    Simultaneous Evolution of the Virial Parameter and Star Formation Rate in Molecular Clumps Undergoing Global Hierarchical Collapse. , keywords =. doi:10.3847/1538-4357/abb8d4 , archivePrefix =. 2002.01594 , primaryClass =

    work page doi:10.3847/1538-4357/abb8d4 2002

  24. [25]

    Filaments in Simulations of Molecular Cloud Formation

    Filaments in Simulations of Molecular Cloud Formation. , keywords =. doi:10.1088/0004-637X/791/2/124 , archivePrefix =. 1308.6298 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/0004-637x/791/2/124

  25. [26]

    Scale-free gravitational collapse as the origin of $\rho \sim r^{-2}$ density profile -- a possible role of turbulence in regulating gravitational collapse

    Scale-free gravitational collapse as the origin of r ^ -2 density profile - a possible role of turbulence in regulating gravitational collapse. , keywords =. doi:10.1093/mnras/sty657 , archivePrefix =. 1803.03273 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/sty657

  26. [27]

    , keywords =

    A compilation of interstellar gas properties. , keywords =. doi:10.1086/156500 , adsurl =

    work page doi:10.1086/156500

  27. [28]

    , keywords =

    The Neutral Atomic Phases of the Interstellar Medium. , keywords =. doi:10.1086/175510 , adsurl =

    work page doi:10.1086/175510

  28. [30]

    Control of star formation by supersonic turbulence

    Control of star formation by supersonic turbulence. Reviews of Modern Physics , keywords =. doi:10.1103/RevModPhys.76.125 , archivePrefix =. astro-ph/0301093 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1103/revmodphys.76.125

  29. [31]

    , keywords =

    Inefficient star formation through turbulence, magnetic fields and feedback. , keywords =. doi:10.1093/mnras/stv941 , adsurl =

    work page doi:10.1093/mnras/stv941

  30. [32]

    , keywords =

    Star Formation Efficiency and Dispersal of Giant Molecular Clouds with UV Radiation Feedback: Dependence on Gravitational Boundedness and Magnetic Fields. , keywords =. doi:10.3847/1538-4357/abe934 , adsurl =

    work page doi:10.3847/1538-4357/abe934

  31. [33]

    A Simple Law of Star Formation

    A Simple Law of Star Formation. , keywords =. doi:10.1088/2041-8205/759/2/L27 , archivePrefix =. 1208.3758 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/2041-8205/759/2/l27 2041

  32. [34]

    Disentangling the independently controllable factors of variation by interacting with the world

    Embedded Clusters in Molecular Clouds. , keywords =. doi:10.1146/annurev.astro.41.011802.094844 , archivePrefix =. astro-ph/0301540 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1146/annurev.astro.41.011802.094844

  33. [35]

    , keywords =

    Molecular Clouds and Star Formation in the Inner Galaxy: A Comparison of CO, H ii, and Far-Infrared Surveys. , keywords =. doi:10.1086/163909 , adsurl =

    work page doi:10.1086/163909

  34. [36]

    , keywords =

    The Edges of Molecular Clouds: Fractal Boundaries and Density Structure. , keywords =. doi:10.1086/170419 , adsurl =

    work page doi:10.1086/170419

  35. [37]

    , keywords =

    Star Clusters Across Cosmic Time. , keywords =. doi:10.1146/annurev-astro-091918-104430 , archivePrefix =. 1812.01615 , primaryClass =

    work page doi:10.1146/annurev-astro-091918-104430

  36. [38]

    ApJ , archivePrefix = "arXiv", eprint =

    On the Star Formation Rates in Molecular Clouds. ApJ , archivePrefix = "arXiv", eprint =. doi:10.1088/0004-637X/724/1/687 , adsurl =

    work page doi:10.1088/0004-637x/724/1/687

  37. [39]

    The Formation of Stars

  38. [40]

    Fragmentation of massive dense cores down to ~1000 AU: Relation between fragmentation and density structure

    Fragmentation of Massive Dense Cores Down to < -0.5ex 1000 AU: Relation between Fragmentation and Density Structure. , keywords =. doi:10.1088/0004-637X/785/1/42 , archivePrefix =. 1401.8292 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/0004-637x/785/1/42

  39. [41]

    , keywords =

    The Single-cloud Star Formation Relation. , keywords =. doi:10.3847/2041-8213/abf564 , archivePrefix =. 2104.04551 , primaryClass =

    work page doi:10.3847/2041-8213/abf564 2041

  40. [42]

    and Olson, K

    Fryxell, B. and Olson, K. and Ricker, P. and Timmes, F. X. and Zingale, M. and Lamb, D. Q. and MacNeice, P. and Rosner, R. and Truran, J. W. and Tufo, H. , title =. 2000 , url =

    2000

  41. [43]

    Leroy and J

    Dyas Utomo and Jiayi Sun and Adam K. Leroy and J. M. Diederik Kruijssen and Eva Schinnerer and Andreas Schruba and Frank Bigiel and Guillermo A. Blanc and M. Star Formation Efficiency per Free-fall Time in nearby Galaxies , journal =. doi:10.3847/2041-8213/aacf8f , url =

    work page doi:10.3847/2041-8213/aacf8f 2041

  42. [44]

    , keywords =

    Tree-based solvers for adaptive mesh refinement code FLASH - II: radiation transport module TreeRay. , keywords =. doi:10.1093/mnras/stab1482 , archivePrefix =. 2105.09644 , primaryClass =

    work page doi:10.1093/mnras/stab1482

  43. [45]

    Mit 5 Textabbildungen

    \"U ber die Verdichtung von H I-Gebieten. Mit 5 Textabbildungen. , year = 1955, month = jan, volume =

    1955

  44. [46]

    , year = 1956, month = jan, volume =

    Boyle's Law and gravitational instability. , year = 1956, month = jan, volume =. doi:10.1093/mnras/116.3.351 , adsurl =

    work page doi:10.1093/mnras/116.3.351 1956

  45. [47]

    XIV.0 Scientific Meeting (virtual) of the Spanish Astronomical Society , year = 2020, month = jul, eid =

    Fragmentation of molecular clouds: the role of magnetic field. XIV.0 Scientific Meeting (virtual) of the Spanish Astronomical Society , year = 2020, month = jul, eid =

    2020

  46. [48]

    The Interstellar Environment of our Galaxy

    The interstellar environment of our galaxy. Reviews of Modern Physics , keywords =. doi:10.1103/RevModPhys.73.1031 , archivePrefix =. astro-ph/0106359 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1103/revmodphys.73.1031

  47. [49]

    The Structure and Evolution of Molecular Clouds: from Clumps to Cores to the IMF

    The Structure and Evolution of Molecular Clouds: from Clumps to Cores to the IMF. Protostars and Planets IV , year = 2000, editor =. doi:10.48550/arXiv.astro-ph/9902246 , archivePrefix =. astro-ph/9902246 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.astro-ph/9902246 2000

  48. [50]

    A robust numerical scheme for highly compressible magnetohydrodynamics: Nonlinear stability, implementation and tests

    A robust numerical scheme for highly compressible magnetohydrodynamics: Nonlinear stability, implementation and tests. Journal of Computational Physics , keywords =. doi:10.1016/j.jcp.2011.01.026 , archivePrefix =. 1101.3007 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1016/j.jcp.2011.01.026 2011

  49. [51]

    Towards the ultimate conservative difference scheme III

    Bram. Towards the ultimate conservative difference scheme III. Upstream-centered finite-difference schemes for ideal compressible flow , journal =. 1977 , issn =. doi:https://doi.org/10.1016/0021-9991(77)90094-8 , url =

    work page doi:10.1016/0021-9991(77)90094-8 1977

  50. [52]

    Riemann Solvers and Numerical Methods for Fluid Dynamics: A Practical Introduction , journal =

    Toro, Eleuterio , year =. Riemann Solvers and Numerical Methods for Fluid Dynamics: A Practical Introduction , journal =

  51. [53]

    Journal of Computational Physics , year = 2009, month = dec, volume =

    A positive MUSCL-Hancock scheme for ideal magnetohydrodynamics. Journal of Computational Physics , year = 2009, month = dec, volume =. doi:10.1016/j.jcp.2009.08.020 , adsurl =

    work page doi:10.1016/j.jcp.2009.08.020 2009

  52. [54]

    Towards a comprehensive scenario

    Global hierarchical collapse in molecular clouds. Towards a comprehensive scenario. , keywords =. doi:10.1093/mnras/stz2736 , archivePrefix =. 1903.11247 , primaryClass =

    work page doi:10.1093/mnras/stz2736 1903

  53. [55]

    From Filamentary Networks to Dense Cores in Molecular Clouds: Toward a New Paradigm for Star Formation

    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 =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.2458/azu_uapress_9780816531240-ch002 2014

  54. [56]

    Physics of the Interstellar and Intergalactic Medium

  55. [57]

    1999 , publisher=

    Introducción a la Física del Medio Interestelar , author=. 1999 , publisher=

    1999

  56. [58]

    1980 , publisher=

    Physics of the Interstellar Medium , author=. 1980 , publisher=

    1980

  57. [59]

    2012 , publisher=

    Finite Element Methods for Navier-Stokes Equations: Theory and Algorithms , author=. 2012 , publisher=

    2012

  58. [60]

    2003 , publisher=

    Fluid Mechanics , author=. 2003 , publisher=

    2003

  59. [61]

    Batchelor, G. K. , year=. An Introduction to Fluid Dynamics , DOI=

  60. [62]

    Philosophical Transactions of the Royal Society of London Series A , year = 1902, month = jan, volume =

    The Stability of a Spherical Nebula. Philosophical Transactions of the Royal Society of London Series A , year = 1902, month = jan, volume =. doi:10.1098/rsta.1902.0012 , adsurl =

    work page doi:10.1098/rsta.1902.0012 1902

  61. [63]

    Chapter 8 - Boundary Conditions , editor =

    Jiri Blazek , keywords =. Chapter 8 - Boundary Conditions , editor =. Computational Fluid Dynamics: Principles and Applications (Third Edition) , publisher =. 2015 , isbn =. doi:https://doi.org/10.1016/B978-0-08-099995-1.00008-7 , url =

    work page doi:10.1016/b978-0-08-099995-1.00008-7 2015

  62. [64]

    2001 , publisher=

    Computational Methods for Fluid Dynamics , author=. 2001 , publisher=

    2001

  63. [65]

    Monthly Notices of the Royal Astronomical Society , volume =

    Wünsch, R and Walch, S and Dinnbier, F and Whitworth, A , title = ". Monthly Notices of the Royal Astronomical Society , volume =. 2018 , month =. doi:10.1093/mnras/sty015 , url =

    work page doi:10.1093/mnras/sty015 2018

  64. [66]

    Salmon and Michael S

    John K. Salmon and Michael S. Warren , abstract =. Skeletons from the Treecode Closet , journal =. 1994 , issn =. doi:https://doi.org/10.1006/jcph.1994.1050 , url =

    work page doi:10.1006/jcph.1994.1050 1994

  65. [67]

    The impact of merging-induced starbursts

    The cosmological simulation code GADGET-2. , keywords =. doi:10.1111/j.1365-2966.2005.09655.x , archivePrefix =. astro-ph/0505010 , primaryClass =

    work page doi:10.1111/j.1365-2966.2005.09655.x 2005

  66. [68]

    , keywords =

    A hierarchical O(N log N) force-calculation algorithm. , keywords =. doi:10.1038/324446a0 , adsurl =

    work page doi:10.1038/324446a0

  67. [69]

    Journal of Computational Physics , year = 1999, month = sep, volume =

    A Solution-Adaptive Upwind Scheme for Ideal Magnetohydrodynamics. Journal of Computational Physics , year = 1999, month = sep, volume =. doi:10.1006/jcph.1999.6299 , adsurl =

    work page doi:10.1006/jcph.1999.6299 1999

  68. [70]

    Journal of Computational Physics , volume=

    An 8-wave MHD solver using Godunov-type algorithms , author=. Journal of Computational Physics , volume=. 1984 , publisher=

    1984

  69. [71]

    Ganapathy and Lynn B

    Anshu Dubey and Katie Antypas and Murali K. Ganapathy and Lynn B. Reid and Katherine Riley and Dan Sheeler and Andrew Siegel and Klaus Weide , title =. doi:10.1016/j.parco.2009.08.001 , url =

    work page doi:10.1016/j.parco.2009.08.001 2009

  70. [72]

    Journal of Computational Physics , keywords =

    The Piecewise Parabolic Method (PPM) for Gas-Dynamical Simulations. Journal of Computational Physics , keywords =. doi:10.1016/0021-9991(84)90143-8 , adsurl =

    work page doi:10.1016/0021-9991(84)90143-8

  71. [73]

    MNRAS , keywords =

    Paul C. Clark and Simon C. O. Glover and Ralf S. Klessen , title =. doi:10.1111/j.1365-2966.2011.20087.x , url =

    work page doi:10.1111/j.1365-2966.2011.20087.x 2011

  72. [74]

    Principles of Astrophysical Fluid Dynamics , DOI=

    Clarke, Cathie and Carswell, Bob , year=. Principles of Astrophysical Fluid Dynamics , DOI=

  73. [75]

    Modeling Collapse and Accretion in Turbulent Gas Clouds: Implementation and Comparison of Sink Particles in AMR and SPH

    Modeling Collapse and Accretion in Turbulent Gas Clouds: Implementation and Comparison of Sink Particles in AMR and SPH. , keywords =. doi:10.1088/0004-637X/713/1/269 , archivePrefix =. 1001.4456 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/0004-637x/713/1/269

  74. [76]

    , keywords =

    The Jeans Condition: A New Constraint on Spatial Resolution in Simulations of Isothermal Self-gravitational Hydrodynamics. , keywords =. doi:10.1086/310975 , adsurl =

    work page doi:10.1086/310975

  75. [77]

    Ammonia in Infrared Dark Clouds

    Ammonia in infrared dark clouds. , keywords =. doi:10.1051/0004-6361:20054128 , archivePrefix =. astro-ph/0601078 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1051/0004-6361:20054128

  76. [78]

    The Milky Way as a Star Formation Engine

    The Milky Way as a Star Formation Engine. Protostars and Planets VI , year = 2014, editor =. doi:10.2458/azu_uapress_9780816531240-ch006 , archivePrefix =. 1402.6196 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.2458/azu_uapress_9780816531240-ch006 2014

  77. [79]

    arXiv e-prints , keywords =

    The Life and Times of Giant Molecular Clouds. arXiv e-prints , keywords =. doi:10.48550/arXiv.2203.09570 , archivePrefix =. 2203.09570 , primaryClass =

    work page doi:10.48550/arxiv.2203.09570

  78. [80]

    On The Nature of Variations in the Measured Star Formation Efficiency of Molecular Clouds

    On the nature of variations in the measured star formation efficiency of molecular clouds. , keywords =. doi:10.1093/mnras/stz1758 , archivePrefix =. 1809.08348 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stz1758

  79. [81]

    The Exciting Lives of Giant Molecular Clouds

    The exciting lives of giant molecular clouds. , keywords =. doi:10.1093/mnras/stt508 , archivePrefix =. 1303.4995 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stt508

  80. [82]

    Density profile evolution during prestellar core collapse: collapse starts at the large scale , journal =

    Gilberto C G. Density profile evolution during prestellar core collapse: collapse starts at the large scale , journal =. doi:10.1093/mnras/stab394 , url =

    work page doi:10.1093/mnras/stab394

Showing first 80 references.