{"id":"bf7477b3-b343-4da3-a4d8-ec602f28f291","arxiv_id":"2512.10564","paper_version":2,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":8,"one_line_summary":"An end-to-end 3D radiation-hydrodynamics simulation of a 10^4 M_sun black hole tidal disruption finds Eddington-limited, wind-mediated emission and slow circularization in the first ~2 fallback times.","lead":"Using a new 3D radiation-hydrodynamics simulation, this paper shows that when a 0.5-solar-mass star is torn apart by a 10,000-solar-mass black hole, the debris does not quickly form an accretion disk. Instead, a radiation-driven wind inflates a large photosphere and keeps the flare near the Eddington luminosity, which upcoming surveys should detect at moderate redshifts.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Nozzle-shock under-resolution is not excluded by the presented convergence tests; the central Eddington-limited wind result may depend on a numerical dissipation rate.","rationale":"The reader's weakest assumption precisely identifies the main vulnerability: the under-resolved pericentric nozzle shock. I agree that this is the most load-bearing concern, because the entire emission mechanism—Eddington-limited luminosity via quasi-spherical wind—is powered by dissipation at that shock. The convergence tests are necessary but not sufficient: they only compare three under-resolved runs, and the observed trend of decreasing dissipation with resolution suggests that the true physical value is not yet reached. The paper itself acknowledges this in Sec. 6, and the required resolution is orders of magnitude smaller than what is achieved. Consequently, the central claim is conditional on the nozzle dissipation being correctly captured, and the provided evidence does not fully demonstrate that. The reader's CONDITIONAL verdict is appropriate: the paper should be accepted only if this concern is addressed (e.g., by a targeted high-resolution nozzle simulation or a subgrid model). No other issue appears more fundamental; the FLD treatment, gravitational softening, and missing MHD are either well-motivated or secondary. Thus I recommend keeping the reader's verdict unchanged.","tokens_in":28090,"tokens_out":5484,"duration_ms":56663,"concrete_test":"Run a local, high-resolution simulation of a single pericentric passage with cell sizes ~1e-4 R_sun, matching the stream's pre-shock properties and using the same physics (opacity, equation of state, FLD radiation). Measure the shock-integrated dissipation rate and the post-shock stream width. Compare these to the same quantities extracted from the global High-resolution run at the same physical time. If they differ by more than a factor of ~2, the global wind properties and light curve are not robust to nozzle resolution.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The paper's central claim—that an optically thick wind advects radiation from a pericentric nozzle shock to produce an Eddington-limited light curve—depends directly on the dissipation rate at that shock. The authors state (Sec. 6) that resolving the nozzle requires cell sizes ~1e-3–1e-4 R_sun, while the High-resolution run uses a minimum cell size of only 0.041 R_sun, orders of magnitude larger. The resolution study (Sec. 4) varies cell mass by factors of 16 but never approaches the required scale. The observed convergence of global quantities to within a factor ~2 across three under-resolved runs does not establish convergence to the true physical value: numerical dissipation in the nozzle shock may be artificially high and only slowly decreasing with resolution. Indeed, Sec. 4 reports that 'increasing the simulation resolution decreases the dissipation rate at the nozzle at any fixed moment in time,' which is a classic signature of numerical dissipation. If the true dissipation rate differs substantially from the converged numerical value, the wind mass-loss rate and the emergent luminosity could change, potentially altering the Eddington-limited light curve and the conclusion that circularization is inefficient. Thus the load-bearing assumption—global insensitivity to the under-resolved nozzle—is not adequately tested.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"Martire et al. present an end-to-end 3D radiation-hydrodynamic simulation of a solar-type star (0.5 Msun, n=1.5 polytrope) disrupted by a 10^4 Msun black hole, run with RICH from before disruption to ~2.2 fallback times, with two additional lower-resolution runs for convergence. The debris stream fails to circularize on the simulated timescale; a radiation-driven, quasi-spherical wind launched near pericenter develops, advecting radiation to a photosphere that expands to ~100 r_t (~10^13-10^14 cm). The bolometric FLD light curve rises to ~2 L_Edd and then plateaus near L_Edd, with photospheric temperatures of a few x 10^4 K. The authors propose an analytic optically thick wind model (Sec. 3.3.2) that connects the trapping radius to the Eddington luminosity, and they estimate that LSST and ULTRASAT could detect such events to z~0.1 and z~0.06.","tokens_in":1399,"tokens_out":1488,"duration_ms":64355,"significance":"If correct, the paper provides the first end-to-end RHD simulation of an IMBH TDE and a concrete physical mechanism—advection in a radiation-driven wind—for the Eddington-limited optical/UV emission seen in many TDEs, without relying on an accretion disk. The systematic three-resolution study is commendable: orbital energies agree to <1%, thermal/radiation energies to 10-15%, and photospheric radius/light curve to within a factor ~2 (Figs. 8 and A1). The model makes testable predictions for upcoming surveys. The main weakness is that the dominant dissipation site (the pericentric nozzle shock) is explicitly admitted to be under-resolved, and the convergence tests do not by themselves establish that the numerical dissipation rate at the nozzle is close to the physical value.","major_comments":[{"comment":"The convergence tests are well designed but do not address the load-bearing concern. The authors state (Sec. 6) that fully resolving the pericentric nozzle requires cell sizes ~10^-3-10^-4 R_sun, whereas the High-res run's minimum cell size is 0.041 R_sun; all three resolutions therefore lie far from the resolved regime. Sec. 4 further reports that increasing resolution decreases the nozzle dissipation rate at fixed time—the hallmark of numerical dissipation—while near-convergence of the total dissipation rate across three under-resolved runs (Fig. 8, R<=2) does not exclude a systematically incorrect value. Since Sec. 3.1 and Fig. 12 identify the nozzle shock as the dominant dissipation site, and since the wind mass-loss rate (Fig. 10) and emergent luminosity scale with that dissipation, the central wind-mediated Eddington-limited emission scenario remains quantitatively conditional on t","section":"Sec. 4, Fig. 8; Sec. 6"},{"comment":"The extrapolation in Eq. (16) from the simulated point to other MBH masses and stellar parameters assumes zeta=0.04, kappa=kappa_T, and r_diss=r_p, where zeta is a simulation output that is itself resolution-sensitive (Fig. 10) and tied to the under-resolved nozzle. The statement in Sec. 5.2 that 'most main sequence TDEs should saturate at near-Eddington peak luminosities' is therefore a stronger claim than the simulation alone supports. Please either derive a physical scaling for zeta from the simulation or explicitly restrict the prediction to the simulated mass/parameter neighborhood.","section":"Sec. 3.3.2, Eq. (16); Sec. 5.2"}],"minor_comments":[{"comment":"Many exponents render as '10 4 M' instead of '10^4 M_sun'. Equation (5) appears to contain a corrupted '√' or bracket; please check the typesetting.","section":"Throughout"},{"comment":"The caption states that the right panels report volume-integrated dissipation rates but does not define the integration volume. Please state whether this is the entire simulation domain or a selected region.","section":"Fig. 2"},{"comment":"The text states t_dyn(r_tr) << t_fb but does not define t_dyn explicitly. A one-line definition would help readers verify the quasi-static wind assumption.","section":"Sec. 3.3.2, Fig. 7"},{"comment":"Eq. (A3) is invalid at shocks; the authors acknowledge this in the footnote, but the main text would benefit from a clearer statement that Eq. (A7) is the discretized weak-form approximation used by RICH.","section":"Appendix A2"}],"recommendation":"major_revision","confidential_remarks":"The paper is within scope for MNRAS and the authors are transparent about the key numerical uncertainty. The nozzle-resolution issue is the main barrier to acceptance: the central wind-mediated luminosity result depends on a dissipation rate that may be numerical in origin. A targeted test or an explicit robustness argument is needed before publication."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The new thing here is real: this is the first 3D end-to-end radiation-hydrodynamics simulation of an IMBH TDE, run with the RICH code at three resolutions. The basic picture is coherent — slow circularization, a radiation-driven wind near pericenter, an expanding photosphere, and a light curve that briefly overshoots Eddington and then settles near it. The convergence tests are a genuine strength: global quantities agree to roughly a factor of two across resolutions, and the energy budgets converge at the 10–15% level. The paper also deserves credit for saying, plainly, where the simulation is under-resolved and what that could affect. The analytic wind model in Sec. 3.3.2 is used to interpret the simulation and to extrapolate, not to fit the light curve, so the central result is not circular.\n\nThe main soft spot is the one both the reader and the stress-test flag: the nozzle shock is the principal dissipation site, and it is under-resolved by a large margin. The authors state that fully resolving it would require cell sizes of 10^-3–10^-4 Rsun; the high-resolution run’s minimum cell is 0.041 Rsun, orders of magnitude larger. Their resolution study never comes close to the required scale, and they report that increasing resolution decreases the nozzle dissipation rate at fixed time — a classic sign that some of that dissipation is numerical. The factor-of-two agreement across three under-resolved runs does not establish convergence to the true physical value. If the true nozzle dissipation is substantially lower, the wind mass-loss rate and the emergent luminosity change. The qualitative conclusions — inefficient circularization, shock-powered wind, Eddington-capped emission — may still survive, but the quantitative peak (2 L_Edd vs something else) and the Eq. 16 extrapolation to other masses inherit that uncertainty. This is a serious limitation, but not a fatal one, and the authors mostly own it.\n\nA secondary annoyance: the data availability promise is vague (“on reasonable request”), and the convergence claims would be much easier to take on faith with input files or a commit hash. The grey FLD treatment and the 192 sight lines are acceptable for bolometric trends, but the color and detectability estimates should be treated as approximate.\n\nWho gets value from this: anyone working on TDE modeling, IMBH demographics, or Rubin/ULTRASAT detection forecasts. It deserves a serious referee. My recommendation: send it to review, and ask the authors for a targeted high-resolution nozzle study or a clear sensitivity analysis on the dissipation rate, plus reproducible simulation details.","headline":"First 3D radiation-hydro IMBH TDE simulation with honest caveats; the central wind/Eddington picture is plausible, but the under-resolved nozzle shock keeps the peak luminosity and extrapolations shakier than the paper fully admits.","tokens_in":28953,"tokens_out":2145,"would_cite":true,"duration_ms":27180,"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":"A wind, not an accretion disk, shapes the early light of a 10,000-solar-mass black hole tidal disruption event.","keywords":["tidal disruption events","intermediate-mass black hole","radiation hydrodynamics","radiation-driven wind","Eddington limit","nozzle shock","photosphere","light curve"],"falsifier":"A single well-observed IMBH TDE with a fast rise and early optical light curve that does not saturate near Eddington (for instance, peak luminosity much above L_Edd with photospheric radius much smaller than about 10^13 cm) would contradict the wind-advection picture, as would a detection of early X-ray emission exceeding the Eddington limit for a 10^4 solar-mass black hole, or spectropolarimetry showing no quasi-spherical expanding photosphere.","tokens_in":27943,"feed_emoji":"🌪️","tokens_out":3674,"duration_ms":36196,"temperature":0.7,"pith_summary":"The paper presents the first end-to-end 3D radiation-hydrodynamics simulation of a star torn apart by a 10^4 solar-mass intermediate-mass black hole, following the debris for more than two fallback times. It claims that early optical and ultraviolet emission from such events is not powered by an accretion disk but by shock dissipation at the returning stream's pericenter passage, which launches a radiation-driven wind. The wind advects photons outward and releases them at an expanding photosphere, producing a bolometric light curve that peaks near twice the Eddington luminosity and then settles at the Eddington value. Because the debris fails to circularize, the classical expectation of a luminous disk fed by fallback is replaced by a nearly Eddington-limited, quasi-spherical outflow. This matters because upcoming surveys like LSST and ULTRASAT could detect dozens of such events per year, and the shape of the early light curve could reveal the presence of intermediate-mass black holes.","feed_headline":"Debris wind, not a disk, powers early TDE light","feed_subtitle":"3D simulation shows a 10^4-solar-mass black hole's flare comes from an Eddington-limited outflow, not accretion.","key_machinery":"The central mechanism is the radiation-driven wind launched from the pericenter region. Flux-limited diffusion couples radiation to the gas, and the return stream's vertical compression at pericenter (the nozzle shock) is the main site of irreversible dissipation. The paper shows this wind behaves as an adiabatic, optically thick outflow: with constant mass-loss rate, density falls as r^-2, radiation energy density as r^(-8/3), and the advected luminosity decays as r^(-2/3). This connects the dissipation luminosity at the base to the Eddington-limited luminosity at the trapping radius via L(r_tr) = L_Edd [(r_g/r_diss)(Mdot_w/Mdot_Edd)]^(1/3), an analytical scaling that explains how shock pow","core_discovery":"For an intermediate-mass black hole tidal disruption event with M_BH = 10^4 solar masses, the returning stellar debris does not circularize into a disk on fallback timescales. Instead, the pericentric nozzle shock dissipates a small fraction of the orbital energy, and that dissipation drives a low-density, radiation-dominated wind. The wind expands quasi-spherically, advecting radiation from small radii; the photosphere embedded in this wind grows to about 10^13 cm with temperatures of a few times 10^4 K. The emergent bolometric luminosity briefly exceeds the Eddington limit, peaking around twice L_Edd, then settles at L_Edd ≈ 3 x 10^41 erg/s. The dissipation rate and emitted luminosity are","pith_inferences":["The same wind mechanism may explain the photospheric radii and temperatures of optically selected TDEs around more massive black holes, offering an alternative to reprocessing models that does not require a pre-existing disk.","A population of 'fast risers' in Rubin/LSST light curves, with rise times of a few days and an Eddington plateau, could provide a demographic handle on intermediate-mass black holes across cosmic time.","The wind's launching efficiency appears tied to the nozzle shock dissipation rate, which is exactly the part of the simulation that is under-resolved; observed early-time luminosities could therefore serve as empirical calibration for the unresolved shock physics."],"forward_implications":["Early-time optical and UV light of IMBH TDEs becomes a probe of shock physics and wind launch, not of the accretion disk; black hole masses inferred from early light curves via disk models could be biased.","The quasi-spherical expanding photosphere and near-Eddington luminosity imply LSST and ULTRASAT can detect such events out to redshifts of about 0.1 and 0.06, respectively, with rates of roughly 100 and 15 per year.","The lack of circularization suggests mass-injection simulations that treat the debris stream as a given may be more robust for IMBH TDEs than for supermassive black hole TDEs.","The Eddington cap is not universal: the analytical scaling predicts it holds for main-sequence disruptions across black hole masses but breaks for white dwarfs, very massive stars, and partial disruptions where the dissipation rate is sub-Eddington.","The under-resolved nozzle shock could change quantitative estimates of stream width and wind mass-loss, but the global results (photospheric radius, light curve, dissipation rate) are converged to within a factor of about two across resolutions."],"fun_headline_variants":["Wind, not disk, explains early TDE glow","Debris wind powers flare from 10^4-solar-mass black hole","TDE light comes from wind, not accretion disk","Eddington-limited wind powers early TDE peak","Debris wind, not disk, produces early TDE flare"],"cache_read_input_tokens":2304,"weakest_assumption_plain":"The global results assume that the numerical dissipation rate of the pericenter nozzle shock, though under-resolved, is close enough to the true rate that the wind mass-loss and luminosity it drives are not substantially different — an assumption the resolution tests support only to within a factor of about two.","fun_headline_variants_meta":{"raw":{"variants":["Wind, not disk, explains early TDE glow","Debris wind powers flare from 10^4-solar-mass black hole","TDE light comes from wind, not accretion disk","Eddington-limited wind powers early TDE peak","Debris wind, not disk, produces early TDE flare"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000628,"raw_usage":{"total_tokens":2793,"prompt_tokens":847,"completion_tokens":1946,"prompt_tokens_details":{"cached_tokens":256},"prompt_cache_hit_tokens":256,"prompt_cache_miss_tokens":591,"completion_tokens_details":{"reasoning_tokens":1877}},"tokens_in":591,"tokens_out":1946,"duration_ms":13371,"temperature":1.0,"reasoning_tokens":1877,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-03T17:05:48.246648+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"A single well-observed IMBH TDE with a fast rise and early optical light curve that does not saturate near Eddington (for instance, peak luminosity much above L_Edd with photospheric radius much smaller than about 10^13 cm) would contradict the wind-advection picture, as would a detection of early X-ray emission exceeding the Eddington limit for a 10^4 solar-mass black hole, or spectropolarimetry showing no quasi-spherical expanding photosphere.","supporting_citations":[],"review_version":1}