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REVIEW

Collapsars - Gamma-Ray Bursts and Explosions in "Failed Supernovae"

Astrophysics · Submitted 19 Oct 1998 · 2 references

Pith's verdict: The disk half of this paper is solid, cross-validated work; the jet half is a plausibility argument, and the authors are more candid about that than the abstract's numbers suggest.

T0 · AI review

How this review was made: An AI referee (selfhosted/deepseek-v4.1-flash) read the paper on October 29, 2026 and answered a fixed list of questions about it. T0 is the starting level every paper gets. The levels describe how deeply Pith has checked the paper, never the authors.

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  3. T2 Compute The paper's code or calculations re-run with the same results.
  4. T3 Formal statement The claims written out in a formal math language a computer can read.
  5. T4 Proof Those claims proved, and the proof checked by computer.

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arXiv IDastro-ph/9810274 (version 1)
Pith IDLLFAOPZC, Pith's permanent record of this paper and its review
CitationA. MacFadyen, S. E. Woosley. "Collapsars - Gamma-Ray Bursts and Explosions in "Failed Supernovae"." arXiv:astro-ph/9810274 (1998). https://pith.science/paper/LLFAOPZC
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Referee report
The paper

The paper claims

A massive star that collapses straight to a black hole can fire a jet clean through itself and make both a long gamma-ray burst and a supernova.

The reading

Some massive stars may skip the usual supernova bounce: the iron core keeps collapsing and quietly becomes a black hole. This paper asks what happens next if the star was rotating, and argues the answer is a gamma-ray burst. Using a two-dimensional hydrodynamics code, the authors follow a $14$ solar mass helium core for twenty seconds after the black hole forms and find a compact accretion disk feeding the hole at about $0.07$ solar masses per second, while the polar directions drain almost unimpeded and leave a low-density channel along the rotation axis. They then deposit energy in that channel at a rate comparable to what neutrino annihilation in the disk should supply, and a tightly collimated outflow punches out through the star in $5$ to $10$ seconds. If this is right, long bursts and stripped-envelope supernovae are two views of one event, and short hard bursts must come from somewhere else.

What carries the argument

The load-bearing mechanism is the collapsar itself: the combination of a failed core-collapse, a neutrino-cooled alpha-viscosity accretion disk, and the density contrast between equator and pole. Three pieces of machinery carry the argument. First, the Shakura-Sunyaev viscosity prescription, with $H$ the density scale height and $c_s$ the sound speed, is implemented as a full stress tensor so the disk can transport angular momentum and dissipate heat; the authors compare an $0.1$ case against a low-viscosity case whose effective numerical alpha is about $0.001$. Second, photodisintegration of helium and heavier nuclei into free nucleons is folded into the equation of state, which sets the disk thickness, the temperature, and hence the neutrino loss rate. Third, the neutrino luminosity and the efficiency of neutrino annihilation are not computed on the grid but interpolated from the steady-state slim-disk tables of a companion paper, as functions of accretion rate and Kerr parameter at a fixed $3$ solar mass hole; that interpolation is what turns the accretion history into the polar energy deposition that drives the jet.

Extended reading notes

Core claim

The paper's central claim is that a rotating massive helium star whose core collapse fails to produce a shock, and instead forms a black hole of $2$ to $3$ solar masses, is not a failure but a collapsar: an engine that produces both a supernova-like explosion and a gamma-ray burst. The argument runs in stages. Infall along the rotation axis is initially unimpeded, so an evacuated hourglass channel opens within a few seconds while equatorial matter piles up in a centrifugally supported disk at a few hundred kilometres. That disk accretes at a sustained, strongly time-variable rate of roughly $0.07$ solar masses per second for at least $15$ seconds and spins the hole up to a Kerr parameter near $0.9$. Energy deposited along the axis, whether by neutrino annihilation or by magnetic processes in the disk, drives a jet collimated to about $10$ degrees half-angle that displaces the overlying star and breaks out in $5$ to $10$ seconds; only after breakout can highly relativistic flow begin. The authors state the observational consequence bluntly: while only a small fraction of supernovae make gamma-ray bursts, all bursts longer than a few seconds should make supernovae like SN 1998bw, and hard, energetic bursts shorter than a few seconds are difficult to make this way.

Load-bearing premise

The energy that drives the jet is not calculated self-consistently: the neutrino luminosity and annihilation efficiency are read off sparse steady-state tables from a companion paper assuming a fixed three solar mass hole and straight-line neutrino paths, and the jet is then switched on by hand at a chosen rate of $5$ times $10^{50}$ erg per second per pole, so if the true efficiency sits near the conservative end of the quoted bracket the polar inflow is never reversed and no jet forms.

Editorial extensions

If this is right

  • Every gamma-ray burst longer than a few seconds should be accompanied by a supernova spectroscopically similar to SN 1998bw, although for distant bright bursts the afterglow from jet deceleration may outshine it.
  • Short, hard bursts with durations near $0.3$ seconds cannot be produced by this engine and require a different progenitor, most plausibly merging neutron stars or a neutron star and a black hole.
  • The enormous spread between GRB 971214 and GRB 980425 reflects mostly how much energy was beamed toward the observer, not a comparably large difference in the total energy released.
  • Hard X-ray precursors are expected as the jet first breaks out of the stellar surface, arriving ahead of the main burst by roughly ten seconds at a radius of $3\times10^{15}$ cm.
  • Collapsars should trace star formation, may be favoured at low metallicity where massive helium cores and rapid rotation survive, and should occur at roughly a per-cent of the supernova rate.

Reading between the lines

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

  • Because the burst is beamed into about $1.5$ per cent of the sky, the model predicts a much larger population of off-axis collapsars visible as broad-lined Type Ic supernovae with weak or absent gamma-rays; finding those without a burst would be strong independent support.
  • The accretion rate sits deliberately near the boundary between advection-dominated and neutrino-cooled disks, so small changes in progenitor mass, angular momentum, or viscosity could shut the jet off while leaving the disk-driven supernova intact. That is a natural route to supernovae without bursts, and it makes the burst rate a steep function of progenitor properties.
  • The reported power at $50$ milliseconds and its overtone in the accretion history suggests a testable discriminant: time structure in a burst light curve on that scale would have to come from the engine, whereas structure on much shorter scales must come from shocks or circumstellar interaction.
  • The jet's energy is quoted as a bracket spanning roughly a factor of thirty. A single well-observed long burst with an independently estimated beaming-corrected energy at the low end of that bracket would strain the neutrino-annihilation channel and push the model toward magnetic extraction from the spinning hole.
Original abstract

Using a two-dimensional hydrodynamics code (PROMETHEUS), we study the continued evolution of rotating massive helium stars whose iron core collapse does not produce a successful outgoing shock, but instead forms a black hole. We study the formation of a disk, the associated flow patterns, and the accretion rate for disk viscosity parameter, alpha ~ 0.001 and 0.1. For the standard 14 solar mass model the average accretion rate for 15 s is 0.07 solar masses per second and the total energy deposited along the rotational axes by neutrino annihilation is (1 - 14) x 10**51 erg, depending upon the evolution of the Kerr parameter and uncertain neutrino efficiencies. Simulated deposition of this energy in the polar regions results in strong relativistic outflow - jets beamed to about 1.5% of the sky. The jets remain highly focused, and are capable of penetrating the star in 5 - 10 s. After the jet breaks through the surface of the star, highly relativistic flow can commence. Because of the sensitivity of the mass ejection and jets to accretion rate, angular momentum, and disk viscosity, and the variation of observational consequences with viewing angle, a large range of outcomes is possible ranging from bright GRBs like GRB 971214 to faint GRB-supernovae like SN 1998bw. X-ray precursors are also possible as the jet first breaks out of the star. While only a small fraction of supernovae make GRBs, we predict that all GRBs longer than a few seconds will make supernovae similar to SN 1998bw. However, hard, energetic GRBs shorter than a few seconds will be difficult to make in this model.

The compiled record

The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 7,841 input tokens, $0.0003 reported.

What the abstract itself states, as probabilities: claims first 0.03 · states limitation 0.90 · human participants 0.01 · controlled comparison 0.04 · randomized assignment 0.01 · states quantitative result 0.98 · compares with prior results 0.20 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v1. Results and the main claim are underlined; .

Using a two-dimensional hydrodynamics code (PROMETHEUS), we study the continued evolution of rotating massive helium stars whose iron core collapse does not produce a successful outgoing shock, but instead forms a black hole. We study the formation of a disk, the associated flow patterns, and the accretion rate for disk viscosity parameter, alpha ~ 0.001 and 0.1. For the standard 14 solar mass model the average accretion rate for 15 s is 0.07 solar masses per second and the total energy deposited along the rotational axes by neutrino annihilation is (1 - 14) x 10**51 erg, depending upon the evolution of the Kerr parameter and uncertain neutrino efficiencies. Simulated deposition of this energy in the polar regions results in strong relativistic outflow - jets beamed to about 1.5% of the sky. The jets remain highly focused, and are capable of penetrating the star in 5 - 10 s. After the jet breaks through the surface of the star, highly relativistic flow can commence. Because of the sensitivity of the mass ejection and jets to accretion rate, angular momentum, and disk viscosity, and the variation of observational consequences with viewing angle, a large range of outcomes is possible ranging from bright GRBs like GRB 971214 to faint GRB-supernovae like SN 1998bw. X-ray precursors are also possible as the jet first breaks out of the star. While only a small fraction of supernovae make GRBs, we predict that all GRBs longer than a few seconds will make supernovae similar to SN 1998bw. However, hard, energetic GRBs shorter than a few seconds will be difficult to make in this model.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 Using a two-dimensional hydrodynamics code (PROMETHEUS), we study the continued evolution of rotating massive helium stars whose iron core collapse does not produce a successful outgoing shock, but instead forms a black hole. contribution 0.58 0.95 0.07 asserted 0.97
s1 We study the formation of a disk, the associated flow patterns, and the accretion rate for disk viscosity parameter, alpha ~ 0.001 and 0.1. contribution 0.78 0.93 0.02 asserted 0.74
s2 For the standard 14 solar mass model the average accretion rate for 15 s is 0.07 solar masses per second and the total energy deposited along the rotational axes by neutrino annihilation is (1 - 14) x 10**51 erg, depending upon the evolution of the Kerr parameter and uncertain neutrino efficiencies. result 1.00 0.93 0.07 asserted 0.96
s3 Simulated deposition of this energy in the polar regions results in strong relativistic outflow - jets beamed to about 1.5% of the sky. result 1.00 0.91 0.10 asserted 1.00
s4 The jets remain highly focused, and are capable of penetrating the star in 5 - 10 s. result 1.00 0.89 0.06 asserted 0.91
s5 After the jet breaks through the surface of the star, highly relativistic flow can commence. result 0.97 0.59 0.05 asserted 0.53
s6 Because of the sensitivity of the mass ejection and jets to accretion rate, angular momentum, and disk viscosity, and the variation of observational consequences with viewing angle, a large range of outcomes is possible ranging from bright GRBs like GRB 971214 to faint GRB-supernovae like SN 1998bw. interpretation 0.84 0.47 0.23 hedged possibility 0.94
s7 X-ray precursors are also possible as the jet first breaks out of the star. result 0.78 0.54 0.04 hedged possibility 1.00
s8 While only a small fraction of supernovae make GRBs, we predict that all GRBs longer than a few seconds will make supernovae similar to SN 1998bw. interpretation 0.90 0.64 0.59 asserted 0.86
s9 However, hard, energetic GRBs shorter than a few seconds will be difficult to make in this model. limitation 0.76 0.57 0.13 hedged possibility 0.54

What kind of paper the classifier reports this is: simulation study 1.00 · evidence from simulation or computation 1.00.

What was examined, and what was not

sources read
  • arXiv listing abstract v1
not examined
  • full text
  • figures and tables
  • references and citing sentences
  • relations to other papers
levels run
  • P abstract
not run
  • S sections
  • T body sentences
  • C citations
  • R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

Figures
Figure 1. — Angular momentum (j) distribution in a 20 M⊙ star evolved from an initially rigidly rotating main sequence star with equatorial velocity 200 km s−1 by Heger, Langer, & Woosley (1998). The solid line gives j on the main sequence; the dotted line is at hydrogen depletion; the dashed line, at helium depletion; and the dash-dotted line is the presupernova star. A decrease of the total stellar mass by mass loss during hydrogen and helium burning is apparent. The distribution of j in the presupernova star shows sharp decreases at the outer edges of convective shells and the helium core…
Figure 2. — Density, radial velocity, specific angular momentum, and enc
Figure 3. — The velocity field in Model 14A at 0.751 s showing early disc forma
Figure 4. — The velocity field at 0.751 s color coded by composition. The colo
Figure 5. — The mass accretion rate as a function of radius within 45 degr
Figure 6. — The simulation (crosses; density, temperature, radial velo
Figure 7. — The ratio of centrifugal force to gravity in Model 14A at a tim
Figure 8. — The density in the central regions of Model 14A 7.60 seconds
Figure 9. — A larger view of the density structure in Model 14A at a later t
Figure 10. — The radial Mach number, Mr, at 7.60 seconds in the standard run, Model 14A, This figure highlights regions of supersonic flow and the location of shocks, especially the one at the edge of the accretion disk at 350 km. The yellow arrows near the equator represent the gas which feeds the disc (the tan toiroidal region interior to 350 km). The red arrows indicate outflow due to centrifugal bounce and viscous heating
Figure 11. — Top panel: Mass accretion rate in Model 14A for the entire 2
Figure 12. — Mass accretion rate as a function of angle during the episod
Figure 13. — On a smaller scale the surface mass density (Σ, top panel) an
Figure 14. — The mass flux field, ρ times v at the same times as
Figure 15. — Fourier power spectrum of the accretion rate shown in Fig.
Figure 16. — Flow patterns in Model 14A at 9.48 s on a larger scale (50000 k
Figure 17. — Origin of the viscosity driven “wind” shown in Fig. 16. Regions o
Figure 18. — Upper panel: The total outward directed kinetic energy in t
Figure 19. — The hole mass and normalized Kerr parameter grow rapidly in t
Figure 20. — Energy deposition rate due to neutrino annihilation in the pola
Figure 21. — Time integrated neutrino annihilation energy. The top panel
Figure 22. — Density structure at 7.52 s in the low viscosity run, Model 14
Figure 23. — Despite its low viscosity, the accretion rate in Model 14B is ab
Figure 24. — Velocity vectors show the onset of a mild explosion produced
Figure 25. — Velocities in the equatorial plane for two runs that did (uppe
Figure 26. — Density, temperature, internal energy per gram, and pr
Figure 27. — Energy density in the jet and surrounding area 0.824 s afte

Figures reproduced from arXiv:astro-ph/9810274 by the authors.

References
How later papers used it

364 later papers cite it

Evidence: substantial. 361 of the citing papers share no author with it, and 9 of those carry a confident label from Pith's citation classifier.

Pith read 40 of the 476 citing sentences, choosing only those whose citation markers point at this paper alone, and wrote the paraphrases from them. The summary, the counts, the evidence level, the links and the quotes come from code; the summary counts the papers listed below. A later paper is listed under a label when Pith's citation classifier gives one of its sentences that label at probability 0.8 or more (0.95 for support), Pith's reading finds that the citing paper itself did it, and a second check confirms the paraphrase against the sentence. This section lists uses only. It does not list criticism or disagreement, so their absence here says nothing about how the paper has been received. Papers that share an author with this one are listed apart, under "By the same authors". A quote is the citing authors' own sentence, shown when their paper's licence is CC BY, CC BY-SA or CC0. JSON

Uses its method or tool 1 of 2 papers with this label
Uses its data or values 1 of 3 papers with this label
  • Used this paper's density of the baryonic accretion disk in the collapsar model of about 10^6±2 g/cm^3 as a comparison for the gas density.

    Supersymmetric Partially Interacting Dark Matter (2014) · 0.96 · paraphrased: the licence does not allow quoting

How the literature uses it

90 arXiv papers cite this in 128 sentences

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

Papers citing it · 60 sentences without a confident label

Uses its method or tool 1 paper
Uses its data or values 2 papers
  • Unless noted otherwise, we take $Ṁ=0.02 M_⊙/s$ [ref] and $v_ej=0.05c$ [ref] .

    Signature of Collapsars as Sources for High-energy Neutrinos and $r$-process Nuclei · Antineutrinos from $β$-decay · 1.00

  • In order for the density of the gas to be comparable to the density of the baryonic accretion disk in the collapsar model ($∼10^6±2 g/cm^3$ [ref] ) the Jeans mass of the gas must be[The Wolf-Rayet stars in Mrk 996 are $∼4.5$ Myr old ($z∼10^-4$) [ref] , therefore the relevant interacting dark matter temperature is that of the dark photon bath approximately today since the interacting dark matter is still coupled with the dark photon bath.] [equation]

    Supersymmetric Partially Interacting Dark Matter · Gamma Ray Burst Phenomenology · 0.96

Compares with it 1 paper
Cites it as support 4 papers
Cites it as background 57 papers

Discussion

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