{"id":"f22d75e8-0b24-49c3-b10e-73ef314b4529","arxiv_id":"2608.09849","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":3,"one_line_summary":"A template of resolved and unresolved gamma-ray sources, added to an unmodified diffuse model, reproduces the shape and spectrum of IceCube's inner-Galaxy neutrino excess.","lead":"This paper builds a map of the Milky Way's gamma-ray sources and uses it to predict where neutrinos should come from. It argues that the recently detected excess of neutrinos toward the inner Galaxy is produced mostly by discrete sources rather than by diffuse cosmic-ray emission.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Cascade smearing angle tuned to IceCube model predictions makes the Figure 4 longitudinal-profile comparison non-independent.","rationale":"The reader's verdict identified the 17.5° smearing angle as the weakest assumption, and I concur that this is the most load-bearing concern. The paper's headline claim is that the longitudinal count profile—and hence the inner-Galaxy excess—is naturally explained by resolved and unresolved gamma-ray sources without additional renormalization. All of the quantitative weight for that claim rests on the cascade profile comparison in Figure 4. The smearing angle is not a nuisance parameter in the usual sense; it is a convolution kernel that redistributes flux across the very bins being compared. Because the angle is explicitly 'chosen to reproduce the model predictions reported by IceCube,' the comparison cannot independently validate the source-template morphology. A concrete, independent determination of the cascade angular response from simulations or event-level estimators would settle this. I do not see the concern as fatal enough to reject the paper: the two independent templates (ReGal-gamma and CTA), the consistent spectral behavior, and the cross-check with tracks all provide supporting evidence that a source population more concentrated toward the inner Galaxy is a plausible interpretation. However, the current presentation overstates the predictive power, matching the reader's CONDITIONAL verdict. The free hadronic fraction chi and the ad hoc 50% rescaling of one unresolved-source model are secondary concerns; they affect normalization, but the spatial morphology comparison is the unique element that gives the paper its novelty. Therefore, I agree with the reader that the verdict should remain conditional pending a robust check of the angular response.","tokens_in":11533,"tokens_out":3970,"duration_ms":42258,"concrete_test":"Recompute the expected cascade counts in Eq. 2 using the event-level angular uncertainties from the Seen et al. (2025) machine-learning reconstruction (or a validated IceCube cascade point-spread function), instead of a fixed 17.5° Gaussian smear. Then re-evaluate the longitudinal profiles for CRINGE alone and CRINGE plus each source template. If the source template no longer improves the fit to the observed black data points (e.g., the central-bin residual changes sign or the reduced chi-squared worsens by >1), the central claim is not robust. As a sensitivity check, repeat the forward-folding for smearing angles of 12°, 15°, 20°, and 25° to see whether the qualitative conclusion depends on the chosen value.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central morphological claim—that a template of non-pulsar gamma-ray sources reproduces the IceCube inner-Galaxy cascade excess—is tested in Figure 4 by forward-folding flux templates with a single, energy-independent 17.5° smearing angle. The paper states (Section 3): 'The smearing angle is based on the angular uncertainties of the cascade events (Seen et al. 2025) and chosen to reproduce the model predictions reported by IceCube.' This wording indicates the angle was tuned to match the very model predictions being used as a benchmark, not derived independently from validated detector simulations. Because the comparison is a binned longitudinal profile, the smearing kernel directly controls how much of the inner-Galaxy source flux leaks into adjacent bins. A different—or energy-dependent—angular response would change the relative heights of the central and outer bins, potentially erasing the claimed preference for the source-rich template over the diffuse-only model. Without an independent check of the angular response, the agreement in Figure 4 is not a blind prediction but a partially calibrated reproduction.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper constructs a template (ReGal-γ) of resolved Galactic γ-ray sources from Fermi-LAT, H.E.S.S., LHAASO, and HAWC catalogs, excluding pulsar-associated and extragalactic sources, and combines it with a diffuse emission model (CRINGE) and two unresolved-source models. Assuming a hadronic fraction χ of each source's γ-ray flux, the authors predict the neutrino sky and compare the resulting inner-Galaxy spectrum and longitudinal cascade count profile with IceCube data. They claim that the template reproduces both the spectral energy distribution and the longitudinal profile without additional renormalization of the emission models, and they test robustness with an independent CTA template. The central morphological argument is that resolved non-pulsar sources are more concentrated toward the inner Galaxy than the diffuse emission, naturally producing the observed peak.","tokens_in":11696,"tokens_out":4637,"duration_ms":45805,"significance":"If established, the claim would be an important step in identifying the origin of the Galactic neutrino excess: it would imply that resolved hadronic γ-ray sources, not only diffuse cosmic-ray interactions, dominate the inner-Galaxy signal. The paper has genuine strengths: it systematically combines current multi-wavelength catalogs, provides a separate cross-check template, and presents energy-dependent spatial predictions that are falsifiable with future IceCube and KM3NeT data. The use of the standard multi-messenger relation (Eq. 1) is appropriate, and the explicit caveats about catalog incompleteness and sky-coverage asymmetries are welcome. However, two load-bearing elements—the hadronic fraction χ and the 17.5° cascade smearing angle—are not fully independent, which weakens the quantitative force of the 'no renormalization' claim.","major_comments":[{"comment":"The 17.5° smearing angle used for all cascade templates is described as 'based on the angular uncertainties of the cascade events (Seen et al. 2025) and chosen to reproduce the model predictions reported by IceCube.' This wording indicates that the smearing kernel was tuned to match the benchmark IceCube predictions rather than derived independently from a validated detector response. Because the comparison in Figure 4 is a binned longitudinal profile, the smearing angle directly controls how much inner-Galaxy flux leaks into adjacent bins; a different or energy-dependent angular resolution could change the relative bin heights and potentially erase the claimed preference for the source-rich template. The authors should either use the detector-level angular response from Seen et al. (2025) without tuning, or show that the profile comparison is insensitive to the assumed smearing angle over a plausible range.","section":"Section 3, Eq. (2), Figure 4"},{"comment":"The hadronic fraction χ is introduced as a free parameter and then effectively inferred from the same inner-Galaxy SED data: the text states that the flux 'can be explained ... for an average hadronic fraction of χ∼0.5–1.' Therefore the normalization of the source component is not a prediction; it is fit to the data. The abstract's claim that the model reproduces the IceCube SED 'without requiring additional renormalization of the emission models' is misleading because the source component carries a freely adjustable multiplicative factor. The authors should either present a proper fit for χ with uncertainties and goodness-of-fit, or rephrase the claim so that it refers only to the unrenormalized diffuse component.","section":"Section 3, Figure 3, Eq. (1)"},{"comment":"The unresolved-source Model B is rescaled to '50% of its original value' on the grounds that non-pulsar sources contribute approximately 50% of the TeV flux. This is an ad hoc correction with no propagated uncertainty, yet it enters directly into the inner-Galaxy flux predictions in Figures 3 and 4 and into the χ∼0.5–1 estimate. The authors should justify this factor more rigorously, or vary it in a sensitivity study to show that the central conclusion is robust to this modeling choice.","section":"Section 2.4, Model B"},{"comment":"The agreement between the model predictions and the IceCube longitudinal counts is assessed only visually ('can explain the excess'). With only nine longitudinal bins and correlated model components, a quantitative goodness-of-fit or likelihood comparison is needed to support the claim that the source-plus-diffuse model is preferred over diffuse-only models. In particular, the paper should report the test statistic or at least the bin-by-bin residuals for the models shown in Figure 4.","section":"Section 3, Figure 4"}],"minor_comments":[{"comment":"The reference for the IceCube data and model predictions, Abbasi et al. (2026), lists only 'https://arxiv.org/abs/tobeupdated'; this placeholder must be replaced with the actual arXiv identifier or journal reference before publication, as the analysis relies on those data.","section":"References"},{"comment":"There is a typo: 'hadronuclear interactions' should be 'hadronuclear interactions'.","section":"Section 3, paragraph 1"},{"comment":"The sentence ending 'models of unresolved sources (Section 2.4.' is missing a closing parenthesis; it should read 'Section 2.4).'","section":"Section 1"},{"comment":"The caption states that the solid lines assume χ=1, while the text says the data can be explained for χ∼0.5–1. Please clarify whether the plotted curves are at χ=1 and whether the χ range is an inference from the vertical offset between the curves and the IceCube band.","section":"Figure 3 caption and text"},{"comment":"The term 'CT template' is used inconsistently; earlier the section is titled 'CTA Template'. Please unify the terminology.","section":"Section 2.2"},{"comment":"The caption says the combined CRINGE plus unresolved-source model is 'normalized to the IceCube best-fit measurement', but the body text emphasizes no renormalization. Please clarify what is meant by 'normalized' here, since the main claim concerns the absence of renormalization.","section":"Appendix B, Figure 5"}],"recommendation":"major_revision","confidential_remarks":"The paper addresses a timely and important question, and the source-template morphology idea is attractive. However, the two central quantitative supports—the free hadronic fraction and the tuned smearing angle—need to be made rigorous before the 'no renormalization' claim can be accepted. If the authors can provide a detector-validated smearing treatment and a real fit for χ (or show insensitivity), the paper would be suitable for publication. I also note that the Abbasi et al. (2026) reference is a placeholder and should be resolved. The self-citation to Seen et al. (2025) for the smearing angle is not inherently problematic, but the tuning language must be removed or justified."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Colleague,\n\nPunchline: the central morphological argument—that a population of non-pulsar gamma-ray sources can explain the inner-Galaxy peak in IceCube's neutrino cascade profile—is plausible and probably right in broad strokes. But the quantitative claim that they reproduce the data 'without additional renormalization' is oversold, because the hadronic fraction chi is essentially a free normalization for the source component, and the 17.5-degree smearing angle used in the count comparison is explicitly tuned to reproduce IceCube model predictions. That makes Figure 4 a partially calibrated reproduction, not an independent check.\n\nWhat's genuinely new and good: ReGal-gamma is a new template combining 4FGL, HGPS, 1LHAASO, and 4HWC, with careful source selection to exclude pulsars and extragalactic sources. The key insight is that resolved gamma-ray sources are more concentrated toward the inner Galaxy than diffuse emission models, so they can naturally create the observed peak without rescaling the diffuse model. The paper tests robustness with an independent CTA template and gives energy-dependent predictions for longitudinal and latitudinal profiles that future IceCube/KM3NeT analyses can check. The authors are also honest in Section 4 about catalog incompleteness and sensitivity differences.\n\nSoft spots: (1) chi is left free and effectively fixed by the inner-Galaxy SED, so the source normalization is not a prediction. The 'no renormalization' headline only applies to the diffuse component. (2) The cascade count comparison uses a single energy-independent 17.5-degree smearing angle, stated to be chosen to reproduce IceCube's model predictions. That is not a valid blind test; a different angular response would change bin-to-bin leakage and could alter the preference for the source template. This concern is real and needs a response from the authors, ideally using validated detector simulations. (3) Model B rescaling to 50% of its flux is ad hoc. (4) No systematic uncertainties on the catalogs or spectral extrapolations are propagated. These are addressable, but they weaken the current quantitative claims.\n\nFor a reader: this is a useful paper for IceCube/KM3NeT analysts and modelers working on the Galactic neutrino excess. It deserves a serious referee; the core morphological argument holds up, but the paper would need to fix the smearing-angle independence and present chi as a fitted parameter, not a prediction, before publication.\n\nYes, send to review.","headline":"The core morphological argument is plausible and worth refereeing, but the paper's quantitative claims are weakened by a tuned smearing angle and a free hadronic fraction that make the 'no renormalization' headline misleading.","tokens_in":12238,"tokens_out":2289,"would_cite":true,"duration_ms":22258,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"This paper claims that the inner-Galaxy excess of high-energy neutrinos seen by IceCube is produced by resolved and unresolved gamma-ray sources that are not powered by pulsars, with no additional renormalization of the diffuse emission…","keywords":["Galactic neutrinos","IceCube","ReGal-gamma template","gamma-ray source catalogs","hadronic cosmic rays","Galactic diffuse emission","inner Galaxy","multi-messenger astronomy"],"falsifier":"Replace the fixed 17.5° smearing with the measured per-event angular uncertainty distribution of IceCube cascade events and recompute the predicted longitude counts; if the central-bin excess disappears, the claimed agreement depends on the tuned smearing. Alternatively, measure the cascade longitude profile above 100 TeV, where ReGal-γ predicts sources dominate over diffuse emission and the peak should narrow; if the observed peak does not narrow with energy, the source-dominance claim is falsified.","tokens_in":11292,"feed_emoji":"🌌","tokens_out":10512,"duration_ms":86798,"temperature":0.7,"pith_summary":"The paper sets out to explain the excess of high-energy neutrinos from the Galactic plane recently reported by IceCube at $5.7\\sigma$, which is most prominent in cascade events above 5 TeV toward the inner Galaxy. It argues that this excess does not require renormalizing the Galactic diffuse emission models; instead, it can be produced by adding a population of resolved and unresolved gamma-ray sources that are not powered by pulsars. The authors build ReGal-γ, a neutrino-emission template made by combining GeV-to-PeV gamma-ray source catalogs and assuming a hadronic fraction for each source's emission, and show that this template is more concentrated toward the inner Galaxy than the diffuse emission alone. Combined with the unrenormalized CRINGE diffuse model and unresolved source populations, it reproduces both the inner-Galaxy neutrino spectrum and the longitudinal count profile measured by IceCube. If correct, discrete hadronic gamma-ray sources, not the cosmic-ray sea, produce most of the inner-Galaxy neutrino peak.","feed_headline":"Gamma-ray sources explain the inner-Galaxy neutrino excess","feed_subtitle":"Adding non-pulsar source populations to an untouched diffuse model reproduces IceCube's spectrum and longitude profile.","key_machinery":"The load-bearing object is ReGal-γ, a spatial and spectral template of candidate hadronic Galactic neutrino sources assembled from gamma-ray catalogs spanning GeV to PeV energies. For every selected source, the paper assumes a hadronic fraction $\\chi$ of the observed gamma-ray flux, converts it to per-flavor neutrino flux with the hadronic relation $E_\\nu^2\\,dN_\\nu/dE_\\nu \\approx (\\chi/2)\\,E_\\gamma^2\\,dN_\\gamma/dE_\\gamma$ at $E_\\gamma = 2E_\\nu$, and combines these sources with the CRINGE diffuse model and unresolved-source models. Predicted cascade counts are obtained by convolving the flux maps with IceCube's effective area and smearing them by a 17.5° angle to account for cascade angular resolution; the comparison of the smeared longitudinal profile with IceCube's nine-bin cascade data is what carries the central claim.","core_discovery":"The central claim is that the observed spectral and spatial distributions of Galactic-plane neutrinos can be simultaneously reproduced by an unrenormalized diffuse emission component plus a population of gamma-ray sources not powered by pulsars. The paper constructs ReGal-γ from resolved gamma-ray sources across 4FGL-DR4, HGPS, 1LHAASO, and 4HWC, filters out pulsars, pulsar wind nebulae, and extragalactic objects, and converts each source's gamma-ray spectrum into a per-flavor neutrino spectrum using $E_\\nu^2\\,dN_\\nu/dE_\\nu \\approx (\\chi/2)\\,E_\\gamma^2\\,dN_\\gamma/dE_\\gamma$ at $E_\\gamma = 2E_\\nu$, with $\\chi$ the hadronic fraction. The resulting source template peaks more sharply toward the inner Galaxy than diffuse templates, so the observed central excess can be fitted without applying extra renormalization factors to the diffuse model. The same conclusion is reached with an independent all-sky source template built from different catalogs, so the paper claims the result is robust to source-modeling choices.","pith_inferences":["If the template is correct, the inner-Galaxy excess should be accompanied by individual neutrino hot spots coincident with the brightest non-pulsar gamma-ray sources (e.g., SNRs and unidentified TeV sources); a stacking search on those positions is a testable extension not performed in the paper.","The 17.5° smearing prescription could be checked against per-event angular-error distributions from the cascade sample; applying the measured distribution instead of a single fixed angle would show whether the central-bin match is sensitive to that choice.","A southern-sky very-high-energy survey should reveal more hadronic sources than current catalogs contain; adding them to ReGal-γ would increase the predicted inner-Galaxy neutrino flux and sharpen the predicted longitude peak.","Because the paper treats the hadronic fraction as a free parameter between 0.5 and 1, the model's normalization is not uniquely predicted; the next test is to measure this fraction for individual source classes using the ratio of neutrino to gamma-ray flux."],"forward_implications":["The inner-Galaxy peak in IceCube's cascade data can be explained without extra scaling of the diffuse emission models, so previous fits requiring renormalization may have been compensating for missing source contributions.","Resolved and unresolved non-pulsar gamma-ray sources, not the cosmic-ray sea alone, dominate the neutrino excess within |l| ≲ 20° and |b| ≲ 15°.","The source population inferred from gamma-rays is more strongly concentrated toward the inner Galaxy than diffuse emission, making spatial morphology a separation tool for source versus diffuse components.","An independent template constructed from different catalogs gives the same qualitative result, indicating the conclusion is robust against catalog and spectral-extrapolation choices.","Future energy-dependent longitudinal and latitudinal neutrino measurements will constrain the hadronic fraction and the spatial distribution of Galactic neutrino sources."],"supporting_citations":[{"why":"Supplies the 5.7σ Galactic-plane detection, the cascade and track samples, the nine longitude bins, and the effective-area/livetime used for the predicted count comparison.","marker":"Abbasi et al. 2026"},{"why":"Provides the CRINGE Galactic diffuse emission model and the unresolved-source model B that together form the 'unrenormalized diffuse component' of the combined prediction.","marker":"Schwefer et al. 2023"},{"why":"Provides the independent CTA/SWGO source template and the synthetic unresolved-source population used as Model A; testing with it shows robustness.","marker":"Abe et al. 2024"},{"why":"Supplies the 4FGL-DR4 GeV catalog used for the Eγ ≤ 1 TeV tier of ReGal-γ.","marker":"Ballet et al. 2024"},{"why":"Supplies the HGPS source spectra and morphologies that populate the inner-Galaxy TeV tier of ReGal-γ.","marker":"Abdalla et al. 2018"},{"why":"Supplies the 1LHAASO catalog including ultrahigh-energy sources and the pulsar-association list used to filter the template.","marker":"Cao et al. 2024"},{"why":"Supplies the Fourth HAWC catalog, which adds northern-sky TeV sources and fills regions not covered by the other catalogs.","marker":"Alfaro et al. 2026"},{"why":"Establishes the earlier conclusion that resolved hadronic sources can exceed diffuse emission toward the inner Galaxy, the hypothesis the paper tests with spatial templates.","marker":"Fang & Murase 2023"},{"why":"Provides the cascade angular uncertainties that motivate the 17.5° smearing angle used in the count prediction.","marker":"Seen et al. 2025"}],"fun_headline_variants":["Non-pulsar sources fit Galactic neutrino excess without renormalization","Gamma-ray source template matches IceCube's inner-Galaxy neutrino excess","Excluding pulsars, gamma-ray sources explain Galactic neutrino sky","ReGal-gamma: a gamma-ray map that predicts the Galactic neutrino sky"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The agreement in the longitude profile rests on smearing every cascade template by a single 17.5° angle whose value was chosen to reproduce IceCube's reported model predictions; if that angle is not the true cascade angular response, the claimed match could change substantially.","fun_headline_variants_meta":{"raw":{"variants":["Non-pulsar sources fit Galactic neutrino excess without renormalization","Gamma-ray source template matches IceCube's inner-Galaxy neutrino excess","Excluding pulsars, gamma-ray sources explain Galactic neutrino sky","ReGal-gamma: a gamma-ray map that predicts the Galactic neutrino sky"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.001499,"raw_usage":{"total_tokens":6031,"prompt_tokens":981,"completion_tokens":5050,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":597,"completion_tokens_details":{"reasoning_tokens":4973}},"tokens_in":597,"tokens_out":5050,"duration_ms":30293,"temperature":1.0,"reasoning_tokens":4973,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-11T05:26:28.964767+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Replace the fixed 17.5° smearing with the measured per-event angular uncertainty distribution of IceCube cascade events and recompute the predicted longitude counts; if the central-bin excess disappears, the claimed agreement depends on the tuned smearing. Alternatively, measure the cascade longitude profile above 100 TeV, where ReGal-γ predicts sources dominate over diffuse emission and the peak should narrow; if the observed peak does not narrow with energy, the source-dominance claim is falsified.","supporting_citations":[],"review_version":1}