{"id":"78b9d9a9-bae6-4c82-b078-baefb0135b21","arxiv_id":"1908.08547","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":5,"one_line_summary":"IceCube's 90% confidence limits cap jetted and non-jetted tidal disruption events at 1.3% and 26% of the astrophysical neutrino flux.","lead":"IceCube searched 9.5 years of neutrino data for neutrinos arriving at the same time and direction as stars ripped apart by black holes, and found no clear excess. The result limits tidal disruption events to at most 1.3% (jetted) and 26% (non-jetted) of the observed astrophysical neutrino flux.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The population-flux cap assumes the 13 golden non-jetted TDEs are unbiased standard candles; if hidden bright TDE subpopulations exist, the 26% cap does not follow.","rationale":"I read the paper as a null-result proceedings contribution: it reports stacking upper limits from four TDE catalogues and a separate AT2018cow limit. The strongest claim is conditional on standard-candle behavior and external TDE rates, and the paper itself flags the rate uncertainty. The reader's weakest-assumption identification matches my main concern, though I would sharpen it: the rate part is already quantified in Figure 1, whereas the representativeness part is not. The golden sample is the only sample used for the non-jetted population cap, and there is no test of whether its 13 optically well-classified TDEs are representative in neutrino luminosity. This does not invalidate the null result, but it means the 26% cap is only as strong as the unquantified representativeness assumption. The reader's CONDITIONAL verdict already captures this, so I do not recommend changing it; the concern is a reason to keep the condition, not to reject the paper. The proposed silver/obscured comparison is a concrete way to test whether the population cap is stable under the choice of representative sample.","tokens_in":6200,"tokens_out":5246,"duration_ms":62864,"concrete_test":"Recompute the Section 4/Figure 1 population-flux cap using the silver and obscured TDE catalogues in place of the golden sample, keeping all other assumptions fixed. If either alternative 90% cap exceeds 26% by more than the rate-uncertainty band, the headline number is not robust to the golden-sample representativeness assumption and should be reported as conditional on that sample.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central limits in Section 4 are derived in two steps: a catalogue-stacking upper limit on neutrino flux from the sources in the sample, and a conversion to a population flux fraction using local TDE rates [13,17] and the assumption that the 13 'Golden' non-jetted TDEs are representative standard candles. The second step is load-bearing. The paper shows rate uncertainty as shaded bands and states that rates are the dominant uncertainty, but it does not quantify how the golden-sample representativeness assumption affects the 26% cap. The golden sample is selected on optical classification quality, not on neutrino luminosity, so it can be biased with respect to neutrino emission. If a rare subpopulation of non-jetted TDEs, absent from the 13 golden sources or from the silver/obscured samples, produced substantially more neutrinos per source, the stacking limit on the golden sample would not constrain that subpopulation, and the true population contribution could exceed 26%. Section 4 explicitly assumes standard-candle behavior and says uncertainty in classification and rates hinders constraints, but the abstract presents the <26% limit without this caveat. The stacked-catalogue null result itself is valid; the concern is specifically the extrapolation from golden-sample limits to a population-wide cap.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"This ICRC proceedings paper reports a search by the IceCube Collaboration for high-energy neutrino emission from populations of tidal disruption events (TDEs) using 9.5 years of muon-neutrino data. Four source catalogues are stacked independently: on-axis jetted TDEs, a 'golden' sample of unambiguously classified non-jetted TDEs, a 'silver' sample of candidate TDEs, and obscured TDEs in dusty galaxies. No significant neutrino excess is found, and 90% confidence upper limits are converted, under a standard-candle assumption and using external TDE rate estimates, into caps on the TDE contribution to the diffuse astrophysical neutrino flux of less than 1.3% for jetted TDEs and 26% for non-jetted TDEs. The paper also reanalyzes AT2018cow in a 130-day TDE-motivated window, finding only a 0.5 sigma excess (compared with the 1.8 sigma reported in the original 3-day Fast Response Analysis) and deriving 90% upper limits on its integrated neutrino emission as a function of spectral index. The outlook section discusses expected improvements from ZTF and LSST.","tokens_in":6478,"tokens_out":6143,"duration_ms":64608,"significance":"If the results hold, this is the first constraint on TDE populations as contributors to the IceCube diffuse neutrino flux, directly addressing a leading candidate class for the unresolved astrophysical neutrino background. The AT2018cow reanalysis is a useful, internally consistent correction of the earlier 1.8 sigma hint, properly accounting for the larger search window. The use of an agnostic stacking method that does not assume relative source weights is a methodological strength, as is the transparent dependence of the population limits on the local TDE rate, which is shown as an uncertainty band. The main scientific value lies in the null result and in the clearly stated conditional nature of the population caps, although that conditionality is not carried through to the abstract.","major_comments":[{"comment":"The conversion from the golden-sample stacking limit to a population-wide cap of 26% for non-jetted TDEs relies on the assumption, stated in Section 4, that the 13 golden TDEs are representative standard candles for the entire non-jetted TDE population. The paper does not quantify how selection on optical classification quality could bias the sample with respect to neutrino luminosity. If a rare subpopulation of non-jetted TDEs, absent from or under-represented in the golden sample, produced substantially more neutrinos per source, the golden-sample stacking limit would not constrain that subpopulation and the true population contribution could exceed 26%. This is a load-bearing assumption for the headline result, so I recommend either a sensitivity study that varies the fraction and luminosity of a hidden bright subpopulation, or at minimum a prominent caveat in the abstract and conclusions that the <26% limit applies only under the standard-candle/representativeness assumption.","section":"Section 4, Figure 1"},{"comment":"The population flux caps also depend on the assumed redshift evolution of the TDE rate, which appears only in the figure captions as 'With evolution from Sun et al.' and is never defined in the text. The local rate values from [13] and [17] are given, but the reader cannot assess how the 26% and 1.3% numbers depend on the chosen evolution prescription or on the normalization of the IceCube diffuse flux [16]. The authors should explicitly state the evolution model and the diffuse flux reference value, and ideally show how the caps would shift under a reasonable alternative evolution model.","section":"Section 4, Figures 1 and 2"}],"minor_comments":[{"comment":"The unbinned likelihood analysis, test statistic, and event selection are not described in the manuscript; they are only cited to references [7] and [9]. For a proceedings paper this is acceptable, but a brief sentence stating the test statistic and pointing to the specific sections of [7] and [9] would greatly improve usability.","section":"Section 3"},{"comment":"The heading 'A T2018cow' contains a typo and should be 'AT2018cow'; in the abstract and introduction, 'AT2018cow are presented' should be 'AT2018cow is presented'.","section":"Section 5"},{"comment":"The y-axis label in Figure 3 appears truncated or ambiguous; please clarify whether the integrated limit is per flavour or summed over flavours, and state the exact units (for example, erg cm^-2 or E^2 dN/dE in GeV cm^-2 s^-1).","section":"Figure 3"},{"comment":"For each of the four catalogues, the paper says the results are consistent with background but does not quote the observed number of events, the expected background, or the resulting p-value. A small table with these quantities would make the null result more concrete.","section":"Section 4"},{"comment":"The text states the limits assume 'an E−2.5 astrophysical neutrino flux' but does not explain how the spectral index enters the stacking search or the limit calculation; a brief clarification of the spectral weighting would help, especially since Figure 3 shows a spectral-index dependence only for AT2018cow.","section":"Section 4"},{"comment":"The sentence 'Higher cadence observations can greatly reduce background by constraining search windows, for example the estimated CCSN explosion time' would be clearer if 'background' were specified as the temporal trial factor or atmospheric background, rather than leaving it ambiguous.","section":"Section 6"}],"recommendation":"major_revision","confidential_remarks":"The paper is a conference proceedings contribution, and the level of methodological detail is typical for the venue. The technical results appear internally consistent, and I see no grounds for rejection. My main concern is that the headline '<26%' limit is presented in the abstract without the standard-candle/representativeness caveat that the body states. If the authors add a caveat and a brief sensitivity discussion, the paper would be acceptable for publication."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Colleague,\n\nFirst things first: this is a genuinely new result. It reports the first public IceCube stacking analysis on TDE populations, and it also reopens AT2018cow with a 130-day TDE window. The null results are clean, and the reanalysis is a good illustration of why the original 1.8 sigma choked-jet window excess needed a trials correction: at 0.5 sigma, it is background.\n\nWhat the paper does well: the catalogue construction is thoughtful. Splitting non-jetted TDEs into golden, silver, and obscured based on classification quality is honest, and the search windows are motivated by the physics rather than tuned to the data. The limits themselves, 1.3% (jetted) and 26% (non-jetted) of the diffuse flux, are internally consistent with the stated assumptions. The paper also says plainly that rates are the dominant uncertainty and that any refined rate estimate can be plugged in directly.\n\nThe soft spots are real but not fatal. The proceedings format omits the likelihood function, test statistic, event selection, and systematic treatment, so an independent reader cannot fully reproduce the numbers. That is a conference-paper limitation, not a hidden flaw. The more substantive issue is the step from stacking limits to population-wide flux caps. That step assumes the 13 golden non-jetted TDEs are representative standard candles. The paper states this assumption, but it does not quantify how a rare, neutrino-bright subpopulation absent from the golden sample would change the cap. The abstract presents the less-than-26% without that caveat. So the stress-test concern lands: the cap constrains the population only if the sample is representative; it is not a hard bound on all conceivable TDEs.\n\nOn the citation pattern: using IceCube's own measured diffuse flux as the denominator is not a problem here, since it is the standard comparison quantity.\n\nWho is the audience? The multimessenger and TDE modeling community. A reader who needs the method details should go to the thesis or the full paper, but the headline result is worth knowing. I would accept it for peer review in a proceedings context, and if it were submitted as a journal paper I would send it to a referee too, primarily to press for more methodological transparency and a clearer discussion of the representativeness caveat.\n\nRecommendation: engage with it, cite it for the first TDE stacking limits, and treat the 26% cap as a conditional statement rather than a robust population constraint.","headline":"First stacking limits on TDE neutrino emission, clean nulls, but the 26% population cap rests on an unquantified standard-candle assumption that the abstract states too crisply.","tokens_in":7013,"tokens_out":2316,"would_cite":true,"duration_ms":23022,"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":"Tidal disruption events make under 26% of cosmic neutrinos","keywords":["neutrino astronomy","tidal disruption events","stacking analysis","diffuse astrophysical neutrino flux","AT2018cow","multi-messenger astronomy","time-domain surveys","IceCube"],"falsifier":"A volume-limited optical survey that measures the local TDE rate with selection bias under control would settle the rate leg of the argument: if the measured rate falls well outside the shaded band used here, the claimed caps must be rescaled proportionally. The representativeness leg could be tested by repeating the stack with a larger, spectroscopically clean TDE sample and checking whether the per-source neutrino limit changes when the 13 golden objects are removed or reweighted.","tokens_in":6002,"feed_emoji":"🔭","tokens_out":8934,"duration_ms":83867,"temperature":0.7,"pith_summary":"This paper asks whether tidal disruption events (TDEs) — stars torn apart by supermassive black holes — can account for a meaningful share of the high-energy neutrinos detected from outside our galaxy. Using 9.5 years of muon-neutrino data and stacking four separate TDE catalogues, the authors find no excess over atmospheric background. Assuming the cleanest TDEs behave as standard candles and adopting published local TDE rates, they conclude that non-jetted TDEs contribute less than 26% and jetted TDEs less than 1.3% of the diffuse astrophysical neutrino flux at 90% confidence. For the transient AT2018cow, they find no evidence of neutrino emission and derive an upper limit over a 130-day window. The result matters because the source of most cosmic neutrinos is still unidentified, and these are the first population-level caps on TDEs as a source class.","feed_headline":"Tidal disruption events make under 26% of cosmic neutrinos","feed_subtitle":"A 9.5-year stacking search also caps jetted TDEs at 1.3% and reports no neutrinos from AT2018cow.","key_machinery":"The machinery that carries the argument is an unbinned likelihood stacking analysis over pre-defined source catalogues. For each TDE the search window covers roughly 30 days before optical peak to 100 days after, extended for sources without a resolved peak and widened further for obscured TDEs to accommodate infrared reprocessing delays; the likelihood combines spatial coincidence, reconstructed energy, and time. The second load-bearing step is the conversion of the stacked per-source upper limit into a population fraction: the golden TDEs are treated as standard candles and the population flux is obtained by multiplying the per-source limit by the assumed local TDE rate, which is why the final caps scale linearly with the rate and carry a shaded uncertainty band.","core_discovery":"The central claim is that tidal disruption events are not a dominant source of the astrophysical neutrino flux. In a source-driven stacking analysis of four TDE catalogues — 3 on-axis jetted, 13 'golden' non-jetted, 24 'silver' non-jetted, and 13 obscured TDEs — the observed neutrino counts are consistent with background in every category. After assuming standard-candle behaviour for the golden non-jetted sample and using the central values of published local TDE rates, the authors derive 90% confidence upper limits of 26% for non-jetted TDEs and 1.3% for jetted TDEs on their share of the diffuse astrophysical neutrino flux, for an $E^{-2.5}$ spectrum. If jetted TDE neutrino luminosity instead scales with black hole mass, the jetted contribution is capped at 0.4% for a mean host black hole mass of $10^{6.5}\\,M_\\odot$. In a separate search, AT2018cow shows at most a $0.5\\sigma$ excess over the 130-day TDE window, so the paper claims no neutrino emission and instead reports an upper limit on the integrated per-flavour energy release across spectral indices.","pith_inferences":["One consequence the paper leaves implicit is that the 26% and 1.3% caps constrain the neutrino efficiency of TDE jets: a model that still wants TDEs to produce ultra-high-energy cosmic rays must keep the neutrino yield per jet below these bounds.","Because the caps scale linearly with the assumed local TDE rate, a future unbiased rate measurement could shift the headline numbers considerably; for example, a rate three times the central value would push the non-jetted cap toward 78%, making the 'less than a quarter' statement contingent on today's rate estimates.","The representativeness of the 13 golden TDEs is testable: once larger spectroscopically confirmed samples exist, one could split the sample by black-hole mass or optical luminosity and check whether the standard-candle assumption changes the stacked limit.","The same analysis template could be transferred to other rare optical transients, such as superluminous supernovae or fast blue optical transients, as soon as optical surveys provide clean, rate-known samples."],"forward_implications":["If the caps are correct, TDEs cannot be the main explanation for the diffuse astrophysical neutrino flux, so the dominant sources must lie elsewhere — blazars, star-forming galaxies, or classes not yet searched.","Neutrino-emission models for TDEs that predict a non-jetted population contribution above 26% or a jetted contribution above 1.3% are ruled out at 90% confidence.","The AT2018cow result means the two neutrinos seen near the explosion were consistent with background over the full 130-day TDE window, so a bright optical transient of this kind does not guarantee detectable high-energy neutrino emission.","Any improvement in the measured local TDE rate can be plugged directly into the published limits without re-running the neutrino analysis, so better optical surveys will immediately tighten or loosen these caps.","Larger and cleaner TDE samples from upcoming time-domain surveys will improve both the stacking sensitivity and the rate estimates, strengthening these population constraints."],"supporting_citations":[{"why":"Supplies the local non-jetted TDE rate whose central value is used to convert the stacked per-source limit into the 26% population cap.","marker":"[13]"},{"why":"Supplies the local jetted TDE rate and its evolution, used for the 1.3% cap and for the black-hole-mass scaling alternative.","marker":"[17]"},{"why":"Defines the diffuse astrophysical neutrino flux against which the TDE contribution fractions are measured.","marker":"[16]"},{"why":"Provides the 9.5 years of muon-neutrino data and the time-dependent likelihood search method on which the stacking analysis is run.","marker":"[7]"},{"why":"Provides the compilation of TDE candidates from which the jetted, golden, and silver catalogues are drawn.","marker":"[14]"},{"why":"Describes the agnostic unbinned likelihood stacking method that avoids assumptions about individual source neutrino luminosities.","marker":"[9]"},{"why":"Supplies the obscured TDE sample and motivates the longer search windows used for infrared-reprocessed candidates.","marker":"[15]"},{"why":"The companion fast-response analysis whose short-window neutrino excess is re-evaluated over the 130-day TDE window for AT2018cow.","marker":"[20]"}],"fun_headline_variants":["TDEs limit: <26% of cosmic neutrinos","Jetted TDEs: <1.3% of neutrino flux","AT2018cow: zero neutrino excess","TDEs not dominant in cosmic neutrino flux","Tidal disruption events: at most 26% of neutrinos"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing premise is that the 13 'golden' TDEs are a representative, standard-candle sample of all non-jetted TDEs and that the published local TDE rates used to scale from per-source limits to population fractions are correct; if either is wrong, the 26% and 1.3% caps shift linearly.","fun_headline_variants_meta":{"raw":{"variants":["TDEs limit: <26% of cosmic neutrinos","Jetted TDEs: <1.3% of neutrino flux","AT2018cow: zero neutrino excess","TDEs not dominant in cosmic neutrino flux","Tidal disruption events: at most 26% of neutrinos"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000939,"raw_usage":{"total_tokens":4027,"prompt_tokens":969,"completion_tokens":3058,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":585,"completion_tokens_details":{"reasoning_tokens":2975}},"tokens_in":585,"tokens_out":3058,"duration_ms":23662,"temperature":1.0,"reasoning_tokens":2975,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-14T11:36:59.653986+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"A volume-limited optical survey that measures the local TDE rate with selection bias under control would settle the rate leg of the argument: if the measured rate falls well outside the shaded band used here, the claimed caps must be rescaled proportionally. The representativeness leg could be tested by repeating the stack with a larger, spectroscopically clean TDE sample and checking whether the per-source neutrino limit changes when the 13 golden objects are removed or reweighted.","supporting_citations":[{"cited_title":"van Velzen, Astrophys","cited_arxiv_id":null,"evidence_quote":"Supplies the local non-jetted TDE rate whose central value is used to convert the stacked per-source limit into the 26% population cap."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Supplies the local jetted TDE rate and its evolution, used for the 1.3% cap and for the black-hole-mass scaling alternative."},{"cited_title":"Auchettl, J","cited_arxiv_id":null,"evidence_quote":"Provides the compilation of TDE candidates from which the jetted, golden, and silver catalogues are drawn."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Describes the agnostic unbinned likelihood stacking method that avoids assumptions about individual source neutrino luminosities."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Supplies the obscured TDE sample and motivates the longer search windows used for infrared-reprocessed candidates."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"The companion fast-response analysis whose short-window neutrino excess is re-evaluated over the 130-day TDE window for AT2018cow."}],"review_version":1}