{"id":"6b15e874-50f3-447f-b489-e8ac76ed00ba","arxiv_id":"2608.07391","paper_version":1,"verdict":"CONDITIONAL","confidence":"HIGH","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":5,"one_line_summary":"Using simulated stellar populations and supernova waveforms, the paper forecasts that the Einstein Telescope will detect essentially all core-collapse supernovae in the Milky Way, with horizons of 20-115 kpc.","lead":"This paper calculates how often the planned Einstein Telescope gravitational wave observatory would detect supernova explosions in our own galaxy. It finds the telescope should catch nearly every such explosion, including ones hidden behind dust from optical telescopes.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Low-mass progenitors dominate the CCSN rate, yet their median ET horizons (~19 kpc for 9 M_sun in Table 2) barely reach the Milky Way's far side; the unshown population-weighted detection fraction is the load-bearing claim.","rationale":"The reader's weakest assumption was that the adopted waveform catalogs represent real Galactic CCSNe, which is explicitly acknowledged in Section 7. My concern is more specific and more internal to the paper's argument: even granting the waveform catalogs, the claim of 'essentially complete coverage' requires that the population-weighted detection fraction be close to unity, and the only quantitative evidence offered is Table 2, whose lowest-mass horizons are comparable to the Milky Way's extent. Because low-mass progenitors dominate the IMF, this is not a marginal edge case but the bulk of the expected CCSN population. The paper asserts the detection fraction is close to unity but does not show the calculation; the customized GWFish code is also not released. This makes the headline conclusion hard to verify. I nonetheless do not call for rejection: the authors explicitly frame the work as a capability demonstration, the independent Choi et al. (2024) result supports the broad conclusion, and the missing information is a quantitative detection-fraction table or code release. The reader's CONDITIONAL verdict already captures the need for additional transparency, so I recommend no change to the verdict, but I flag this unshown detection fraction as the most load-bearing point to check.","tokens_in":15571,"tokens_out":7267,"duration_ms":75763,"concrete_test":"Recompute, with the customized GWFish pipeline used by the authors, the detection fraction for the ET-2L configuration as the percentage of TRILEGAL progenitors with SNR>=10, broken down by progenitor-mass bin, using the same random sky-position and geocentric-time sampling. Report (a) the mass-resolved detection fractions and (b) the Kroupa-IMF-weighted total detection fraction. If the total falls below, say, 95%, the 'essentially complete coverage' wording in Section 8 must be weakened. A simpler analytic cross-check: integrate the TRILEGAL distance distribution against the cumulative detection-probability curve implied by the 5th/50th/95th percentile horizons in Table 2 for each waveform; if more than ~10% of simulated progenitors are below SNR=10, the claim is not supported by the paper's own numbers.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The conclusion in Section 8 that ET will provide 'essentially complete coverage' of Milky Way CCSNe rests on the Section 6 assertion that 'the detection fraction is close to unity throughout the considered progenitor-mass range.' No numerical support or mass-resolved detection fractions are presented. This matters because the adopted Kroupa IMF places roughly 40% of CCSNe below 12 M_sun, and Table 2 gives median detection horizons for the lowest-mass waveforms of only 19.1 kpc (9 M_sun, Radice et al. 2019) and 31.0 kpc (9.25 M_sun, Vartanyan et al. 2023), with 5th-percentile horizons as low as 11.1 kpc. Since the Sun is ~8 kpc from the Galactic center and the disk extends to 15-20 kpc, a non-negligible fraction of the disk lies beyond these distances. The quoted horizon is a median over isotropic sky positions and geocentric times, whereas the actual TRILEGAL population is concentrated in the Galactic plane and not centered on the detector; the relation between the two is not derived in the text. If the low-mass waveforms are representative, the population-weighted efficiency could still be high, but the paper does not show it. The central claim therefore depends on a stated-but-unquantified detection fraction, and because the customized GWFish code is not released, it cannot be checked from the manuscript. This is the weakest load-bearing link: the headline conclusion is only as secure as this unshown number.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper forecasts the detectability of gravitational waves from core-collapse supernovae (CCSNe) with the Einstein Telescope, alone and in combination with Cosmic Explorer, focusing on the Milky Way and the Magellanic Clouds. The analysis combines the GWFish simulation framework, extended with time-domain CCSN waveforms from the Radice et al. (2019) and Vartanyan et al. (2023) catalogs, with a TRILEGAL synthetic stellar population of 9–25 M_solar progenitors. The authors derive a Galactic CCSN rate of 1.9 per century from the TRILEGAL star formation history and a Kroupa IMF, compute detection horizons for several ET configurations, and conclude that ET will provide essentially complete coverage of Milky Way CCSNe, with a representative 15 M_solar progenitor detectable to ~100 kpc in the 2L configuration. They further estimate that only ~45% of Galactic CCSNe would be optically visible at a limiting magnitude of 22, emphasizing the multimessenger role of gravitational waves.","tokens_in":15835,"tokens_out":3369,"duration_ms":33130,"significance":"If the central claim holds, the result is of direct relevance for ET science planning and multimessenger observing strategies: it would mean that essentially every Galactic CCSN occurring during ET's operation produces a detectable gravitational-wave signal regardless of dust extinction, enabling guaranteed multimessenger targets. The paper is careful to use state-of-the-art public waveform catalogs, explicit detector PSDs with high-frequency transfer-function corrections, and a realistic stellar population synthesis model. The authors also acknowledge major limitations, including the absence of rotation, magnetic fields, and progenitors above 25 M_solar. However, the headline conclusion rests on a population-weighted detection fraction that is asserted rather than demonstrated, and the statistical interpretation of the quoted horizons is not clearly defined.","major_comments":[{"comment":"The claim that 'the detection fraction is close to unity throughout the considered progenitor-mass range' is not supported by any quantitative, mass-resolved detection fraction. Table 2 reports median detection distances over random sky positions and geocentric times, with 5th and 95th percentiles. For the lowest-mass waveforms (9 M_solar Radice and 9.25 M_solar Vartanyan), the median horizons are only 19.1 and 31.0 kpc, with 5th-percentile horizons of 11.1 and 19.0 kpc. Because the adopted Kroupa IMF places a substantial fraction of CCSNe below 12 M_solar and the TRILEGAL disk extends to 15–20 kpc, the population-weighted detection efficiency is not obviously unity. The paper must present the actual detection fraction as a function of progenitor mass, computed by applying the nearest-waveform assignment to the TRILEGAL source positions and marginalizing over the detector response, not just a median over isotropic positions.","section":"Section 6, Table 2"},{"comment":"The phrase 'with a 90% confidence level' misstates what is computed. The horizons in Table 2 are medians with 5th and 95th percentiles over random right ascension, declination, and geocentric times. These are not 90% confidence intervals in the detection-probability sense, and the 5th percentile is not a '90% confidence' lower bound. If the intent is to quote a conservative reach, the paper should explicitly say '5th percentile of the SNR distribution'; if the intent is that 90% of sources at a given distance are detected, that quantity must be derived from the SNR distribution and the detection threshold, not from the horizon percentiles. The abstract and Section 8 should be rephrased accordingly.","section":"Abstract, Section 6, Table 2"},{"comment":"The quantitative claims for Magellanic Clouds detection fractions—'approximately 20% with ET-2L and 6% with ET-∆, increasing to more than 70% for either configuration when CE40 is included'—are given without any derivation, figure, or table. If these numbers come from the TRILEGAL LMC/SMC simulations, the calculation should be described and the fractions should be presented as a function of distance or mass, with the assumed mass distribution stated. As written, these are unverifiable conclusion-only numbers.","section":"Section 8"},{"comment":"The nearest-mass mapping from each simulated star to the closest waveform in the catalog is a key approximation, but the paper does not report how many stars are assigned to each waveform mass, nor does it discuss the systematic error introduced by this discretization. In particular, Table 2 shows a non-monotonic trend of median horizon with mass (e.g., the 12.25 M_solar Vartanyan waveform has a shorter horizon than the 11 M_solar waveform), so nearest-mass assignment can introduce nontrivial biases. The paper should quantify the distribution of assigned masses and, if possible, test sensitivity to the mapping choice.","section":"Section 5"}],"minor_comments":[{"comment":"The sentence 'we estimated the signal at random geocenteric times' contains a typo ('geocenteric' should be 'geocentric'), and the following sentence has a duplicated phrase: 'to build to construct SNR distributions'.","section":"Section 5"},{"comment":"The sentence fragment 'Regarding the detection prospects at the Magellanic-Cloud.' is incomplete and should be merged with the following sentence.","section":"Section 8"},{"comment":"The caption says 'Assuming a ET (2L) configuration'; 'a' should be 'an'.","section":"Figure 3 caption"},{"comment":"The phrase 'a sligh improvement' contains a typo ('sligh' should be 'slight').","section":"Section 6"},{"comment":"The reported optical visibility fraction of 45±3% is based on only three values of the mean absolute magnitude M_B = -15, -17, -19; the uncertainty should be described as a range over these model assumptions, not as a statistical error bar.","section":"Section 7"},{"comment":"The acronym 'TRIdimensional modeL of thE GALaxy' is awkwardly expanded; consider a standard presentation such as 'TRILEGAL (Girardi et al. 2005, 2012)' with a parenthetical full name.","section":"Section 3"}],"recommendation":"major_revision","confidential_remarks":"The paper is within the scope of A&A and addresses a timely topic for third-generation gravitational-wave detectors. The main concern is not the methodology itself, which is reasonable, but the gap between the computed horizon distributions and the headline claim of 'essentially complete coverage.' The authors should be asked to provide the missing population-weighted detection fractions and to clarify the statistical meaning of their '90% confidence' phrasing. These are fixable within the manuscript's scope, so I recommend major revision rather than rejection. I do not see signs of circular reasoning: the rate estimate and the detectability calculation are based on independent ingredients (TRILEGAL SFR and external waveform catalogs)."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The main result holds up. With Einstein Telescope, a Galactic core-collapse supernova is essentially a guaranteed gravitational-wave detection, and the paper gives concrete numbers for how the 2L and triangle configurations differ, and what adding CE40 buys. The TRILEGAL-based progenitor population is a real improvement over the uniformly distributed or single-mass source populations that earlier forecasts used.\n\nThe rate estimate (1.9 per century from the TRILEGAL star-formation history) sits comfortably in the literature range, and the horizons in Table 2 (roughly 20-115 kpc for ET alone, up to ~170 kpc with CE) are so much larger than the Milky Way's size that the central conclusion is not sensitive to the waveform catalog details. The useful new outputs are the 2L standalone advantage of 15-20%, shrinking to 5-10% in an ET+CE network, and the dust-obscured fraction: only about 45% of Galactic CCSNe would be visible to an optical survey with a limiting magnitude of 22. That last number is a good reminder for anyone planning EM follow-up.\n\nThe soft spots are addressable. The '90% confidence level' in the abstract is really the 5th-95th percentile range of the horizon distances, not a detection probability; readers will trip on that until it's reworded. More substantively, the claim in Section 6 that the detection fraction is 'close to unity throughout the considered progenitor-mass range' is stated without a numeric, mass-resolved breakdown. Figure 5 shows a cumulative curve that appears to back it, but the text should give the actual fractions, especially for the low-mass end, where Table 2 gives median horizons of 19-31 kpc. That would address the concern about the 9-12 solar-mass part of the Kroupa IMF contributing most of the events. The customized GWFish code is not released, so a referee or motivated reader cannot reproduce the population-weighted network calculations without asking the authors. Minor: the 45 ± 3% dust-visible uncertainty only covers the intrinsic luminosity spread, not the E(B-V)/tau353 conversion or the assumed limiting magnitude.\n\nNone of this breaks the paper. The central forecast is robust, and the authors are honest that the waveforms are non-rotating and capped at 25 solar masses; they flag rotation, magnetic fields, high-mass progenitors, and GW memory as future extensions. That is the right tone for a forecasting study.\n\nThis deserves a serious referee. I would send it out, and I'd ask for the mass-resolved detection fractions and the code (or at least a reproducibility appendix with the essential settings) before accepting. It's a useful paper for the ET design discussion and for anyone planning the multimessenger response to the next Galactic supernova.","headline":"ET will see nearly every Milky Way CCSN; the paper's numbers are credible, the 2L vs triangle and CE-network comparisons are new and useful, and the soft spots are wording and missing mass-resolved fractions, not the central claim.","tokens_in":16514,"tokens_out":5255,"would_cite":true,"duration_ms":48282,"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":"The Einstein Telescope will register a gravitational-wave signal from essentially every core-collapse supernova that explodes in the Milky Way during its operation, even if dust hides the explosion from optical telescopes.","keywords":["gravitational waves","core-collapse supernovae","Einstein Telescope","detection horizon","Milky Way","Magellanic Clouds","multimessenger astronomy","proto-neutron star"],"falsifier":"Compare the first core-collapse supernova observed in neutrinos during Einstein Telescope's operational lifetime: if it occurs within the Milky Way, or in the Magellanic Clouds within the quoted horizon, and no signal-to-noise-ratio-10 gravitational-wave signal is found, the near-complete coverage claim is falsified. A complementary statistical check is to rerun the same pipeline with newly published waveform catalogs that include rotation and magnetic fields; if the resulting horizon distribution drops below roughly 20 kpc for most progenitors, the 'essentially complete' conclusion fails.","tokens_in":15308,"feed_emoji":"🌌","tokens_out":10670,"duration_ms":86457,"temperature":0.7,"pith_summary":"Core-collapse supernovae are expected to emit gravitational waves from the churning, oscillating proto-neutron star formed at the moment of collapse, but no such signal has been seen yet. This paper asks whether the next-generation Einstein Telescope will finally catch one from our own Galaxy, and answers yes: with realistic 3D waveform models and a simulated Milky Way stellar population, essentially every core-collapse supernova within the Galaxy should be detectable, regardless of dust. For a representative 15 solar-mass progenitor, the dual-L configuration reaches about 100 kpc, past the Galaxy's edge and partway to the Magellanic Clouds. Because optical surveys would miss roughly half of these events behind dust, the gravitational-wave channel would be the way to get a complete census. A detection probability near unity per event, combined with a Galactic rate near 1.9 per century, implies about a 32% chance of catching at least one during 20 years of Einstein Telescope operation.","feed_headline":"Einstein Telescope: nearly all core-collapse supernovae in reach","feed_subtitle":"The next Galactic core-collapse supernova should be seen in gravitational waves even if dust hides its light.","key_machinery":"The analysis is carried by a customized gravitational-wave simulation framework that combines three pieces: two published catalogs of 3D radiation-hydrodynamics waveforms covering 9-25 solar-mass non-rotating progenitors, spanning early post-bounce emission through late-time proto-neutron-star oscillations; a synthetic stellar population of the Milky Way and Magellanic Clouds, giving each potential progenitor a mass, sky position, and distance; and detector response calculations for two Einstein Telescope designs (a 10 km triangle and a 15 km dual-L) plus a 40 km Cosmic Explorer, including high-frequency transfer-function corrections that matter in the roughly 100-1000 Hz supernova band. For every simulated star, the closest available waveform is matched and an optimal network signal-to-noise ratio is computed from the integrated power spectral density, and the detection horizon is defined as the distance at which that SNR reaches 10 at 90% confidence. The same machinery yields the rate estimate by tying the Galactic core-collapse rate to the star-formation history used in the population synthesis.","core_discovery":"The central claim is that the Einstein Telescope, operating alone, will provide essentially complete coverage of core-collapse supernovae occurring in the Milky Way, with detection horizons between roughly 20 and 115 kpc at 90% confidence depending on progenitor mass and waveform, and that a network adding a Cosmic Explorer detector extends the reach to about 170 kpc, covering most of the Magellanic Clouds. The authors further find that a 15 solar-mass progenitor is detectable to about 100 kpc with the dual-L configuration, that the 2L layout outperforms the triangular design by 15-20% in standalone operation, and that the optically visible fraction of Galactic core-collapse supernovae is only 45% +/- 3% at a limiting magnitude of 22. More than half of all events would therefore be hidden from optical surveys but open to gravitational waves.","pith_inferences":["If future waveform catalogs include rapidly rotating progenitors or black-hole-forming collapses above 25 solar masses, the horizons could shift substantially; the paper notes that rotating models often produce stronger, more coherent signals, so the present numbers may be conservative for that subpopulation.","A neutrino-triggered, time-frequency-constrained search could recover a meaningful fraction of events missed by an unmodeled gravitational-wave search; the paper cites a roughly 30% efficiency gain for a nearby SASI-dominated model, suggesting joint analysis pipelines are the natural next step.","The strong extinction result implies that high-cadence infrared or X-ray follow-up, not just optical wide-field surveys, should be included in the multimessenger strategy for the inner Galactic disk.","The 'complete coverage' prediction is testable statistically rather than event-by-event: if Einstein Telescope accumulates several decades of clean data with no Galactic core-collapse supernova while neutrino detectors see bursts, then either the rate or the waveform assumptions are wrong."],"forward_implications":["If the central claim holds, the next Milky Way core-collapse supernova that happens during Einstein Telescope operation will produce a detectable gravitational-wave signal even if it is completely hidden by dust.","Einstein Telescope's gravitational-wave coverage of the Magellanic Clouds depends on configuration and waveform: roughly 20% of Small Magellanic Cloud-like progenitors are detectable with ET-2L alone, rising to more than 70% when Cosmic Explorer is added.","The 15 km dual-L configuration is the better standalone choice, giving 15-20% larger horizons than the 10 km triangle; the gap shrinks to 5-10% inside an ET+CE network.","About 45% +/- 3% of Galactic core-collapse supernovae would be visible to optical surveys at magnitude limit 22, so gravitational waves plus neutrinos are needed for a complete census of Galactic events.","At the adopted rate of 1.9 events per century and near-unity detection efficiency, there is roughly a 32% chance of detecting at least one Galactic core-collapse supernova in 20 years of Einstein Telescope operation."],"supporting_citations":[{"why":"Supplies one of the two 3D waveform catalogs, covering early-to-intermediate post-bounce gravitational-wave emission for 9-25 solar-mass progenitors.","marker":"Radice et al. (2019)"},{"why":"Supplies the complementary waveform catalog extending to late-time proto-neutron-star oscillations, which carry much of the signal energy.","marker":"Vartanyan et al. (2023)"},{"why":"Provides the population synthesis model used to build the Milky Way and Magellanic Cloud progenitor distributions with masses, positions, and distances.","marker":"Girardi et al. 2005, 2012"},{"why":"The simulation framework customized to compute detection horizons and network responses for time-domain supernova waveforms.","marker":"Dupletsa et al. (2023)"},{"why":"Defines the Einstein Telescope design configurations and sensitivities (10 km triangle and 15 km dual-L) used in the analysis.","marker":"Branchesi et al. (2023)"},{"why":"Supplies the Planck Galactic dust extinction map used to compute the optically visible fraction of core-collapse supernovae.","marker":"Abergel et al. (2014)"},{"why":"Independent study finding that Einstein Telescope should detect supernova gravitational waves throughout the Milky Way, used as a consistency comparison.","marker":"Choi et al. (2024)"},{"why":"Provides the combined Galactic core-collapse supernova rate estimate underpinning the expected event rate and detection probability.","marker":"Rozwadowska et al. (2021)"}],"fun_headline_variants":["Einstein Telescope: nearly all Milky Way supernova GWs in reach","ET will see supernova GWs that dust hides in the Milky Way","Milky Way supernovae: ET's GW horizon covers the galaxy","Einstein Telescope: supernova GWs at 100 kpc and beyond"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing premise is that the simulated non-rotating 9-25 solar-mass waveforms represent the real gravitational-wave emission of Galactic core-collapse supernovae; if real signals are systematically weaker or morphologically different, the quoted horizons and the near-complete coverage would not hold.","fun_headline_variants_meta":{"raw":{"variants":["Einstein Telescope: nearly all Milky Way supernova GWs in reach","ET will see supernova GWs that dust hides in the Milky Way","Milky Way supernovae: ET's GW horizon covers the galaxy","Einstein Telescope: supernova GWs at 100 kpc and beyond"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000346,"raw_usage":{"total_tokens":1918,"prompt_tokens":987,"completion_tokens":931,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":603,"completion_tokens_details":{"reasoning_tokens":851}},"tokens_in":603,"tokens_out":931,"duration_ms":8193,"temperature":1.0,"reasoning_tokens":851,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-10T05:14:09.480387+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Compare the first core-collapse supernova observed in neutrinos during Einstein Telescope's operational lifetime: if it occurs within the Milky Way, or in the Magellanic Clouds within the quoted horizon, and no signal-to-noise-ratio-10 gravitational-wave signal is found, the near-complete coverage claim is falsified. A complementary statistical check is to rerun the same pipeline with newly published waveform catalogs that include rotation and magnetic fields; if the resulting horizon distribution drops below roughly 20 kpc for most progenitors, the 'essentially complete' conclusion fails.","supporting_citations":[{"cited_title":"2019, The Astrophysical Journal Letters, 876, L9","cited_arxiv_id":null,"evidence_quote":"Supplies one of the two 3D waveform catalogs, covering early-to-intermediate post-bounce gravitational-wave emission for 9-25 solar-mass progenitors."},{"cited_title":"S., & White, C","cited_arxiv_id":null,"evidence_quote":"Supplies the complementary waveform catalog extending to late-time proto-neutron-star oscillations, which carry much of the signal energy."},{"cited_title":"2005, As- tronomy & Astrophysics, 436, 895","cited_arxiv_id":null,"evidence_quote":"Provides the population synthesis model used to build the Milky Way and Magellanic Cloud progenitor distributions with masses, positions, and distances."},{"cited_title":"2023, Journal of Cosmology and Astroparticle Physics, 2023, 068","cited_arxiv_id":null,"evidence_quote":"Defines the Einstein Telescope design configurations and sensitivities (10 km triangle and 15 km dual-L) used in the analysis."},{"cited_title":"A., Aghanim, N., et al","cited_arxiv_id":null,"evidence_quote":"Supplies the Planck Galactic dust extinction map used to compute the optically visible fraction of core-collapse supernovae."},{"cited_title":"2024, ApJ, 975, 12","cited_arxiv_id":null,"evidence_quote":"Independent study finding that Einstein Telescope should detect supernova gravitational waves throughout the Milky Way, used as a consistency comparison."}],"review_version":1}