{"id":"6a7f7343-6843-41ff-836b-9c6eee72be82","arxiv_id":"2411.11000","paper_version":3,"verdict":"CONDITIONAL","confidence":"HIGH","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":3,"one_line_summary":"Synthetic light curves and spectra of six high-mass stripped-star explosions show broad, faint behavior and reveal that standard analytic ejecta mass estimators can overestimate the true mass by up to a factor of 2.6.","lead":"This paper uses radiation-flow simulations to create fake light curves and spectra for explosions of very heavy, stripped stars. It finds that these models look like real broad-lined supernovae in shape but are too dim, and warns that common mass-estimating formulas can overshoot the true ejected mass by more than two and a half times.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Fixed 56Ni mass/mixing is the load-bearing assumption: the up-to-2.6x rise-time-based mass overestimate is controlled by the same mixing parameter that is imposed as an input, not derived from the explosion physics.","rationale":"The reader's weakest_assumption is the fixed 56Ni mass and mixing, and my stress-test agrees with and sharpens that identification. The key point is that the same fixed mixing parameter directly shapes the rise time used in the very estimator whose bias is the paper's headline result (up to 2.6x, abstract and Figure 5). The paper is transparent about this limitation in Section 3.1, and the pipeline has real strengths (public data, self-consistent explosion energies from C20, and a calibrated comparison method). However, the paper's community-facing warning against rise-time estimators for high-mass SESNe is only as strong as the range of 56Ni and opacity assumptions explored, and only one nickel prescription is used. The abstract vs. text 'consistent' vs. 'marginally resemble' mismatch is a real but minor overstatement. I recommend keeping the CONDITIONAL verdict: the central bias claim is plausible and important, but a single targeted parameter scan would either confirm it or force a meaningful qualification.","tokens_in":22580,"tokens_out":5983,"duration_ms":53804,"concrete_test":"Re-run the MZAMS=45 model (Mej=10.85 Msun) and one low-mass model (e.g., MZAMS=120) with the same hydro profiles but MNi in {0.03, 0.07, 0.15} Msun and mixing out to {20%, 60%, 100%} of the ejecta mass. Recompute tr, Lpeak, and the Wheeler+2015 peak-based Mej ratio. If the factor 1.8-2.6 overestimate persists across all nine combinations, the abstract's bias claim is robust; if the ratio changes by more than ~30% or drops below 1.5 in any corner, the claim must be restated as conditional on the assumed 56Ni yield and mixing.","verdict_should_be":"CONDITIONAL","load_bearing_attack":"The central quantitative claim is that the Wheeler+2015 rise-time method overestimates ejecta mass by a factor up to 2.6 (Section 3.3, Figure 5). The rise time tr used in that estimator is read from the simulated light curve, but Section 3.2 and Figure 4 show tr is strongly controlled by 56Ni mixing: stronger mixing shortens the rise by tens of days. Both MNi=0.07 Msun and the 60% mixing mass cut are imposed inputs (Section 2.3, Table 1), not outputs of the explosion. The paper itself concedes in Section 3.1 that the absence of nuclear-burning networks prevents a direct connection between progenitor properties and 56Ni yield and that the mixing is fixed. Section 3.3 also notes the rising light curve is sensitive to the SNEC opacity floor, calibrated for SNe II (Bersten et al. 2011), which could itself lengthen the rise. Therefore, the 1.8-2.6x ratio in Figure 5 is a property of one nickel/opacity prescription, and the conclusion that high-initial-mass progenitors systematically fool rise-time estimators is not yet established as a physics-driven finding. A second, smaller issue: the abstract says light-curve shape is 'consistent' with broad-LC SESNe while Section 3.2 says 'marginally resemble'--an overstatement that matters because the comparison sample anchors the astrophysical relevance. The helium-line persistence is not the load-bearing issue because the paper's own Section 3.5 carefully documents the recomb-NLTE caveat.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper presents synthetic bolometric light curves and optical/NIR spectral time series for six stripped-envelope supernova models derived from solar-metallicity, non-rotating Wolf-Rayet progenitors with MZAMS = 45-120 Msun. The progenitors are evolved with KEPLER, exploded with the neutrino-driven STIR/FLASH framework, and post-processed with SNEC and TARDIS. The main results are: (1) the models are broad and faint compared to the typical SESN population, marginally resembling observed broad-LC SESNe; (2) the Wheeler et al. (2015) rise-time-based ejecta mass estimator overestimates the true ejecta mass by up to a factor 2.6, while the Haynie & Piro (2023) calibrated tail method is accurate to ~20% within its calibrated mass range but underestimates high-mass models; and (3) He I lines, especially 1.083 um, persist even with 0.02 Msun of helium, so He line strength is not a simple mass indicator. The authors provide public data on Zenodo and explicitly discuss the main caveats, including the fixed 56Ni mass/mixing and the approximate helium treatment.","tokens_in":22914,"tokens_out":6847,"duration_ms":63538,"significance":"The modeling pipeline is state-of-the-art and the paper provides a valuable public set of self-consistent explosion-to-spectra models for high-mass stripped progenitors. Its main strength is the direct test of widely used analytic ejecta-mass estimators against physics-driven explosion simulations, and the explicit, repeated acknowledgment of the fixed inputs (56Ni mass of 0.07 Msun, 60% mixing, SNEC opacity floor) and the recomb-NLTE helium approximation. If the headline overestimate factor (up to 2.6) is robust to variations in these inputs, the result would be an important caution for the SESN community. The helium-line persistence result, if confirmed with more detailed NLTE treatment, would support and extend Teffs et al. (2020) and Williamson et al. (2021). However, the quantitative claims are currently presented without a sensitivity analysis of the key imposed parameters, which limits the strength of the conclusions.","major_comments":[{"comment":"The central quantitative claim that the Wheeler et al. (2015) rise-time method overestimates ejecta mass by a factor up to 2.6 is not robust to the imposed 56Ni mixing and opacity floor. Section 3.2 and Figure 4 show that the rise time is shortened by tens of days when 56Ni is fully mixed, and Section 3.3 itself notes that the SNEC opacity floor was calibrated for SNe II and may be too high for SESNe. Since both the 0.07 Msun 56Ni mass and the 60% mixing mass cut are fixed inputs (Section 2.3, Table 1) rather than outputs of the explosion model, the 1.8-2.6x range in Figure 5 reflects one prescription. Please quantify the sensitivity of the inferred Mej ratios to (a) the mixing fraction (e.g., using the fully mixed cases already shown in Fig. 4) and (b) a lower opacity floor, or explicitly state that the claim is conditional on the fiducial prescription. This is load-bearing because the abstract and conclusion present the overestimate as a general property of high-initial-mass progenitors.","section":"Section 3.3, Figure 5"},{"comment":"The abstract states that the light curve shape 'is consistent with observed SESNe with broad light curves,' but Section 3.2 says the rise/decline rates 'marginally resemble' those of observed broad-LC SESNe. Because the comparison sample is the anchor for the astrophysical relevance of the models, the wording should be aligned. Either strengthen the quantitative comparison (e.g., show the distribution of t-1/2 and t+1/2 for the observed sample and the models, with uncertainties) or soften the abstract claim. As written, the overstatement could mislead readers about the degree of agreement.","section":"Abstract vs Section 3.2"},{"comment":"The abstract's claim that the Haynie & Piro (2023) method 'reduces uncertainties to an average of 20% within the calibrated ejecta mass range' is supported only by a visual inspection of Figure 5 for five models sharing the same 56Ni input. Please list the inferred masses and the individual ratios for the Mej < 5 Msun models, state the number of models used, and clarify whether the 20% is a mean or median absolute deviation. This is load-bearing because the conclusion encourages use of the H23 method.","section":"Section 3.3, Table 3 and Figure 5"}],"minor_comments":[{"comment":"There are several typos in the text; for example, 'descrisd' should be 'described' and 'Hmma,rize' appears to be garbled for 'summarize'. Please proofread the manuscript.","section":"Section 2.3"},{"comment":"In Section 3.3, 'approxiamated' should be 'approximated'.","section":"Section 3.3"},{"comment":"In Section 2.4, 'Marto Carlo' should be 'Monte Carlo'.","section":"Section 2.4"},{"comment":"The footnote b gives MFallBack = 1.518 and 0.366 Msun, while the text in Section 3.3 gives 1.52 and 0.37 Msun; please make the precision consistent.","section":"Table 1"},{"comment":"In Figure 4, the label 'MZAM S' is missing an underscore and should read 'MZAMS'.","section":"Figure 4"},{"comment":"The He I 1.083 um persistence claim should be accompanied in the abstract or conclusion by the caveat that the recomb-NLTE approximation may overestimate NIR He lines; the paper already states this in Section 3.5, but the abstract and conclusion do not reflect it.","section":"Section 3.5 and Abstract"}],"recommendation":"major_revision","confidential_remarks":"The paper is a solid modeling contribution and is within the scope of ApJ. The main concern is that the headline quantitative claims are presented without a sensitivity analysis of the imposed 56Ni mixing and opacity floor; the authors should either provide that analysis or soften the claims. The self-citations are appropriate and not excessive. I recommend major revision."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"First thing to know: this is the first public grid of synthetic light curves and spectra for physics-driven explosions of high-mass stripped stars (45-120 M_sun), built from Couch+2020's turbulence-aided neutrino-driven explosions mapped into SNEC/TARDIS. That alone makes it worth a look. It also does a clean quantitative test of the Wheeler+2015 and Haynie+Piro 2023 ejecta mass formulas against simulation outputs, and the data are public on Zenodo. The authors are transparent about the pipeline's limits; the helium treatment caveat is documented in detail.\n\nThe soft spot is exactly where the stress-test note lands. The headline result--rise-time mass estimators overestimate ejecta mass by up to 2.6x--is real for these models, but the rise times are controlled by the 56Ni mixing fraction (set to 60% of the ejecta) and the nickel mass (0.07 M_sun), both imposed inputs because SNEC/STIR lack nuclear networks. The paper itself says rise time is sensitive to mixing and opacity floor. So the factor of 2.6 is a property of one nickel/opacity prescription, not a robust physics-driven finding. The direction of the bias is plausible and worth knowing, but I would not present the number as generic.\n\nThe abstract also says the light-curve shape is 'consistent' with broad-LC SESNe while the text says 'marginally resemble.' That is an overstatement; it matters because the comparison anchors the paper's relevance.\n\nWhat survives: the calibrated H23 tail method works within its calibrated ejecta mass range (below ~5 M_sun), and fails badly for the one 10.85 M_sun model. That is useful and a fair warning. The He I 1.083 micron persistence with tiny helium masses is consistent with Teffs+2020, and the authors appropriately hedge the optical He results.\n\nMinor: the explosion energies are extrapolated analytically, and the sample is six models. Those are caveats, not flaws.\n\nVerdict: a paper that deserves a serious referee. It is a solid modeling contribution with public outputs, and the caveats are mostly acknowledged in the text. Recommended action: referee it, then ask for a softened abstract and an explicit statement in Section 3.3 that the overestimation factor depends on the imposed mixing/opacity choices. This is CONDITIONAL, not reject.","headline":"First public grid of physics-driven high-mass stripped-star explosions; the headline mass-bias factor is real but rides on an imposed nickel/mixing prescription, and the abstract overstates light-curve agreement.","tokens_in":23482,"tokens_out":2741,"would_cite":true,"duration_ms":29135,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"High-mass stripped-star explosions reveal that the standard rise-time formula overestimates ejecta mass by up to 2.6 times, while calibrated late-time tails stay within 20 percent in range.","keywords":["stripped-envelope supernovae","Wolf-Rayet progenitors","radiative transfer simulations","synthetic bolometric light curves","ejecta mass estimation","helium spectral diagnostics","neutrino-driven explosions","nickel-56 mixing"],"falsifier":"Compute the same six explosions with a nuclear-reaction network (or with nickel masses varied across the plausible range, e.g., 0.03 to 0.15 solar masses) and compare the resulting light curves with observed broad SESNe; if the models then match the observed peak luminosities, the claim that high-mass Wolf-Rayet progenitors are too faint falls. Alternatively, apply the rise-time and late-time formulas to a set of real SESNe with independent ejecta-mass measurements; if rise-time masses do not systematically exceed tail masses, the claimed 2.6-fold overestimate does not generalize.","tokens_in":22386,"feed_emoji":"💥","tokens_out":8223,"duration_ms":77434,"temperature":0.7,"pith_summary":"This paper uses radiative-transfer simulations to turn physics-driven neutrino explosions of six massive Wolf-Rayet stars into synthetic supernova light curves and spectra. It finds that the explosions with high ejecta masses (4–11 solar masses) produce light-curve shapes matching observed stripped-envelope supernovae with broad light curves, but their peak luminosities fall below the observed range. The paper then tests the analytic formulas observers use to infer ejecta mass from light curves: the standard rise-time formula overestimates the true ejecta mass by up to a factor of 2.6 for these high-mass explosions, while a calibratable late-time tail method stays within about 20% inside its calibrated range. It also finds that the near-infrared helium line at 1.083 microns appears even when only 0.02 solar masses of helium remains, so line presence cannot directly measure helium mass. Realistic helium features, the paper argues, require full radiative-transfer modeling for each explosion because line strength depends on nickel distribution, composition, and the radiation field.","feed_headline":"Rise-time light-curve formulas overestimate ejecta mass 2.6-fold","feed_subtitle":"Standard rise-time estimates run high by up to 2.6-fold; calibrated tails hit 20 percent in range.","key_machinery":"The machinery is a sequential pipeline: stellar evolution of solar-metallicity Wolf-Rayet stars, a turbulence-aided neutrino-driven explosion that supplies self-consistent energy and remnant mass, a one-dimensional radiation-hydrodynamics code that produces the bolometric light curves, and a Monte Carlo radiative-transfer code that synthesizes spectra. The test instruments are the analytic ejecta-mass estimators applied to the synthetic light curves, namely the rise-time formula, the raw late-time tail formula, and a late-time formula calibrated on lower-mass binary-stripped progenitors. Throughout, the fixed inputs of 0.07 solar masses of nickel-56 mixed out to 60 percent of the ejecta set the peak luminosity, rise time, and late-time tail, as well as the radiation field that drives helium line formation.","core_discovery":"On its own terms, the paper claims that a self-consistent chain from stellar evolution to neutrino-driven explosion to radiative transfer shows that stripped high-mass Wolf-Rayet stars are viable progenitors of the broad-lightcurve subclass of stripped-envelope supernovae, but only for light-curve shape, not for peak brightness. The same chain exposes a systematic flaw in a widely used estimator: applying the standard rise-time formula to these models overestimates ejecta mass by 80% to 160% (up to a factor 2.6), because the assumed constant opacity and the rise-time measurement do not capture the physics of these extended, faint explosions. A late-time decay-tail estimator calibrated on lower-mass progenitors performs much better, with average uncertainties near 20%, provided the true ejecta mass lies inside its calibrated range; outside that range, as in the most massive model, it underestimates the ejecta mass by about 70%. Spectroscopically, the paper establishes that helium features are not a simple mass meter: the He I 1.083 micron line is saturated even at 0.02 solar masses of helium, and the optical helium lines are controlled by the radiation field, nickel distribution, and mixing rather than helium abundance alone.","pith_inferences":["If the 2.6-fold rise-time bias is real, correcting observed samples of broad-lined SESNe with late-time methods could shift their inferred ejecta masses down, potentially reducing the apparent need for very massive progenitors.","Because the nickel mass is fixed, the 'too faint' peak luminosity is a conditional result: models with a self-consistent or larger nickel yield might land inside the observed luminosity range, which would make high-mass single-star progenitors more attractive.","The saturated near-infrared helium line implies that NIR classification alone cannot distinguish helium-poor from helium-rich events; pairing NIR spectra with optical helium lines and full radiative-transfer fits is a testable route to hidden-helium constraints.","The paper's comparison suggests a clean observational test: measure both rise-time and late-time ejecta masses for a sample of broad SESNe; if the rise-time values systematically exceed the tail values, the bias claimed here is present in real data."],"forward_implications":["If these models represent real high-mass stripped explosions, then published ejecta masses for broad-lightcurve SESNe derived from rise-time formulas are systematically too high, by as much as a factor of 2.6.","The calibrated late-time tail method can be trusted to roughly 20 percent only when the true ejecta mass is within its lower-mass calibration range; applying it to a ~10.85-solar-mass ejecta underestimates the mass by about 70 percent.","High-initial-mass Wolf-Rayet explosions produce broad, faint light curves, so they cannot by themselves explain the typical bright stripped-envelope supernovae; extra power sources (or lower-mass progenitors) are needed for the normal population.","A strong He I 1.083 micron line cannot be used to infer helium abundance, since even 0.02 solar masses of helium saturates the feature, so Type Ib/Ic classification by near-infrared helium alone is unreliable.","Optical helium-line strength is set by nickel distribution, composition, and radiation field, so each new hydrodynamic model requires its own radiative-transfer calculation before helium content can be interpreted."],"supporting_citations":[{"why":"Supplies the Wolf-Rayet progenitor structures and the 0.07 solar-mass nickel-56 yield that seeds the explosions and radiation field.","marker":"Sukhbold et al. (2016)"},{"why":"Provides the turbulence-aided, neutrino-driven explosion outcomes (energy, remnant mass, ejecta mass) used as input.","marker":"Couch et al. (2020)"},{"why":"Defines the mapping from explosion output to the light-curve code, including the asymptotic-energy correction and the pure-helium replacement of the shocked region.","marker":"Barker et al. (2022)"},{"why":"Provides the one-dimensional radiation-hydrodynamics code that produces the bolometric light curves and photospheric parameters.","marker":"Morozova et al. (2015)"},{"why":"Provides the Monte Carlo radiative-transfer code used to synthesize the spectral time series.","marker":"Kerzendorf & Sim (2014)"},{"why":"Compiles the rise-time and late-time analytic ejecta-mass estimators whose biases the paper measures.","marker":"Wheeler et al. (2015)"},{"why":"Provides the calibrated late-time tail estimator that performs within 20 percent in its calibrated ejecta-mass range.","marker":"Haynie & Piro (2023)"},{"why":"Offers the case study showing that He I 1.083 micron saturates with trace helium, against which the persistent helium line result is compared.","marker":"Teffs et al. (2020)"},{"why":"Supplies the helium non-LTE treatment and the hidden-helium upper limit that motivates the helium analysis.","marker":"Hachinger et al. (2012)"},{"why":"Shows that carbon and helium features depend on radiation field and mixing, supporting the caution about abundance inferences.","marker":"Dessart et al. (2015)"}],"fun_headline_variants":["Rise-time formulas inflate ejecta mass 2.6-fold","Calibrated decay tails cut ejecta mass error to 20%","Helium line strength not tied to helium mass","Stripped Wolf-Rayet explosions match light-curve shapes not peaks","Helium lines demand full simulation in stripped supernovae"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The whole comparison rests on the fixed assumption that every explosion produces 0.07 solar masses of nickel-56 mixed out to 60 percent of the ejecta, because the explosion and light-curve codes do not track nuclear burning; if the real nickel yield or mixing differs, the peak luminosities, rise times, tails, and helium-line strengths would all shift.","fun_headline_variants_meta":{"raw":{"variants":["Rise-time formulas inflate ejecta mass 2.6-fold","Calibrated decay tails cut ejecta mass error to 20%","Helium line strength not tied to helium mass","Stripped Wolf-Rayet explosions match light-curve shapes not peaks","Helium lines demand full simulation in stripped supernovae"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000631,"raw_usage":{"total_tokens":3008,"prompt_tokens":1133,"completion_tokens":1875,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":749,"completion_tokens_details":{"reasoning_tokens":1797}},"tokens_in":749,"tokens_out":1875,"duration_ms":15548,"temperature":1.0,"reasoning_tokens":1797,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-12T19:04:23.021456+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Compute the same six explosions with a nuclear-reaction network (or with nickel masses varied across the plausible range, e.g., 0.03 to 0.15 solar masses) and compare the resulting light curves with observed broad SESNe; if the models then match the observed peak luminosities, the claim that high-mass Wolf-Rayet progenitors are too faint falls. Alternatively, apply the rise-time and late-time formulas to a set of real SESNe with independent ejecta-mass measurements; if rise-time masses do not systematically exceed tail masses, the claimed 2.6-fold overestimate does not generalize.","supporting_citations":[],"review_version":1}