{"id":"762e5117-ddf6-41ef-a642-9a112bca7109","arxiv_id":"2607.06777","paper_version":1,"verdict":"CONDITIONAL","confidence":"HIGH","novelty_score":6.0,"correctness_risk":"low","formal_verification":"none","parameter_count":5,"one_line_summary":"AT 2022wtn produced a uniquely powerful non-relativistic radio outflow (v~0.21c spherical; energy ~3.8e49 erg) consistent only with a delayed accretion-disk state transition.","lead":"Multi-year radio monitoring of TDE AT 2022wtn shows a delayed, unusually fast and energetic non-relativistic outflow. The data favor an accretion-disk state-transition origin over jets, unbound debris, or standard winds, highlighting diversity in TDE outflows.","discovery_kind":"extension","skeptic_critique":{"model":"grok-4.5","headline":"Launch-date free-expansion extrapolation is the load-bearing step that sets the high β used to exclude competing models.","rationale":"The Reader correctly isolated the free-expansion launch-date extrapolation as the weakest assumption that underpins the high-β numbers used to eliminate every alternative except a delayed state-transition outflow. The multi-epoch SEDs, equipartition formalism (with public code), and systematic model comparison are otherwise solid; freezing p and the spherical/conical geometries affect absolute scale but not the qualitative ranking once β is fixed. Because the paper already flags the launch-date uncertainty and the Reader already assigned CONDITIONAL for exactly this reason, no further verdict shift is warranted. The concrete test above simply makes the sensitivity quantitative.","tokens_in":25611,"tokens_out":565,"duration_ms":5703,"concrete_test":"Re-fit the first five Req points allowing a free-expansion-to-Sedov break (R ∝ t then R ∝ t^{2/5}) with a free t_break and re-derive β and Eeq at each epoch; if the resulting β falls below ~0.1c for any plausible t_break consistent with the δt=97 d non-detection, the velocity-based exclusion of CIO/accretion-wind models no longer holds.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The strongest claim rests on β ≈ 0.21c (spherical) / 0.41c (conical) and Eeq ~ 3.8e49 / 1.8e50 erg being high enough to rule out unbound debris, CIO, and accretion winds (Section 5.3). Those β values come from Eq. 7 with t measured from a launch date of δt ≈ 138 days, itself obtained by linear extrapolation of the first five Req points under free expansion (Section 4.2). The paper itself notes that a pure power-law fit gives R ∝ t^0.53 and a launch near 179 days, and that a broken power-law (free expansion then Sedov-like) is also allowed but unconstrained. Shifting the launch later by only ~40 days lowers β into the 0.1c range that the competing models already accommodate, while early deceleration would further reduce the free-expansion β. Thus the exclusion of the other mechanisms is only as secure as the free-expansion assumption over the first five epochs.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.5","summary":"The manuscript presents multi-epoch VLA and GMRT radio observations of the TDE AT 2022wtn spanning 97–866 days after optical discovery. The authors fit self-absorbed synchrotron SEDs (Granot & Sari 2002 form, νm < νa < νc), fix p to its mean value 3.26, and apply an updated equipartition formalism (Rohde et al., in prep., building on Barniol Duran et al. 2013 and Matsumoto & Piran 2023) for both spherical (fA = 1) and conical (fA = 0.1) geometries. They report β ≈ 0.21c and Eeq ∼ 3.8 × 10^49 erg (spherical) or β ≈ 0.41c and Eeq ∼ 1.8 × 10^50 erg (conical), with a circumnuclear density profile next ∝ R^−2.08. After excluding free-free absorption, a cooling break, and a relativistic jet, they compare the derived energy and velocity against unbound debris, collisionally-induced outflows, accretion-driven winds, and an accretion-disk state-transition outflow, concluding that only the last is consistent. The central claim is that AT 2022wtn is a uniquely powerful non-relativistic radio TDE whose outflow is best explained by a delayed state-transition launch at δt ≈ 138 days.","tokens_in":25888,"tokens_out":1302,"duration_ms":12742,"significance":"If the high β and Eeq and the state-transition interpretation hold, the paper adds a well-sampled, multi-frequency radio data set and a carefully documented equipartition analysis to the growing sample of non-relativistic radio TDEs, and it strengthens the case that delayed disk-state transitions can power luminous, fast outflows. Strengths include quantitative rejection of free-free absorption (Appendix B) and cooling-break alternatives (Section 3.3), systematic comparison to other TDEs with a consistent equipartition pipeline (Figure 5), public modeling code, and an explicit multiwavelength consistency check against Onori et al. (2025). The result is of clear interest to the TDE and radio-transient communities even if the launch-date assumption is later refined.","major_comments":[{"comment":"Section 4.2 and Eq. (7): the reported β ≈ 0.21c (spherical) / 0.41c (conical) that exclude unbound debris, CIO, and accretion winds rest on a free-expansion launch date of δt ≈ 138 days obtained by linear extrapolation of the first five Req points. The paper itself notes that a pure power-law fit yields R ∝ t^0.53 and a launch near 179 days, and that a broken power-law (free expansion then Sedov-like) is allowed but unconstrained. A later launch by only ∼40 days lowers β into the ∼0.1c range already accommodated by the competing models. The exclusion of those models is therefore only as secure as the free-expansion assumption over the first five epochs. The authors should either (i) present a quantitative sensitivity study of β and Eeq versus launch date (including the power-law and broken-power-law cases) and restate the model comparison with the resulting range, or (ii) provide indepen","section":null},{"comment":"Section 5.3.5 and the abstract: the claim that “only” an accretion-disk state-transition outflow is consistent is stronger than the evidence once launch-date uncertainty is acknowledged. Even under the preferred launch date, the spherical β ≈ 0.21c sits at the upper edge of the 0.05–0.3c range quoted from Wu et al. (2025), and the conical β ≈ 0.41c exceeds it. The paper should soften the language to “favored” or “most consistent among the models considered,” and should explicitly note which of the two geometries remains inside the state-transition velocity window after the launch-date sensitivity is folded in.","section":null}],"minor_comments":[{"comment":"Section 3.2 / Appendix D: fixing p to the mean 3.26 after free fits show large epoch-to-epoch variation is reasonable, but the text should state the quantitative impact on Eeq and Req of using the free-p posteriors (or of fixing s = 1) so readers can judge the systematic floor.","section":null},{"comment":"Section 4.1 / footnote 17: the choice of fΩ = 4 (spherical) versus 0.1 (conical) produces a factor-of-40 difference in next relative to some earlier TDE analyses; a short sentence clarifying why this geometric convention is preferred would help cross-paper comparisons.","section":null},{"comment":"Appendix C: for the conical geometry the calculated γm ∼ 4 (rather than the assumed γm = 2) reduces Eeq by ∼40 %. This should be flagged in the main text when conical energies are quoted, or the conical comparison sample should be recomputed with consistent γm.","section":null},{"comment":"Figure 3 and Table 2: the final epoch shows an upturn in Fp; a brief remark on whether this is physical or an artifact of the GMRT/VLA joint fit would be useful.","section":null},{"comment":"Typographical: “F arley”, “W alter”, “calu-lation”, and a few missing spaces after periods appear in the draft; a careful proofread is needed.","section":null}],"recommendation":"minor_revision","confidential_remarks":"The load-bearing launch-date assumption is real but fixable with a sensitivity table; I do not see a fatal inconsistency. The paper is a solid contribution once the language around “only” and the free-expansion extrapolation is tightened. Fit for a standard astrophysical journal after minor revision."},"author_rebuttal":null,"desk_editor":{"model":"grok-4.5","letter":"This is the first detailed multi-epoch radio data set and equipartition analysis of AT 2022wtn. The event sits at the high end of the non-relativistic TDE population in both energy and velocity, and the authors use that to favor a delayed accretion-disk state-transition outflow over jets, unbound debris, CIOs, and ordinary winds.\n\nWhat they did well is clear. The VLA+GMRT coverage from 97–866 days is thorough, SEDs are well sampled, free-free absorption and a late cooling break are checked and rejected with numbers, and they systematically compare the derived β and E against the main competing channels. They also ship the flux table and the equipartition code. The modeling is an incremental but careful update of the Barniol-Duran/Matsumoto-Piran framework (p-dependent C, hot-proton corrections). Freezing p after free fits looked unphysical is a reasonable choice; the free-p run would have produced an absurd energy jump.\n\nThe soft spot is real but not fatal. The high β that excludes the other models comes from measuring time from a launch date of δt≈138 days, obtained by linear extrapolation of the first five Req points under free expansion. The paper itself notes that a pure power-law fit gives R∝t^0.53 and a launch near 179 days, and that a broken power-law is allowed but unconstrained. Shift the launch later by ~40 days and β drops into the 0.1c range that the competing models already accommodate. Early deceleration would do the same. So the ranking of mechanisms is only as secure as that free-expansion assumption. Geometry (spherical vs conical) and εe also move the absolute numbers, but the authors vary both and the qualitative conclusion is less sensitive to those than to the launch date.\n\nThis is useful for people who work on radio TDEs and disk-state-change models. It does not open a new technique or settle a major open question, but it adds a well-observed high-energy, high-velocity thermal event to the sample and is honest about the modeling choices. I would send it to referees; the data and the comparative analysis deserve a careful look, and the launch-date sensitivity is something a referee can force them to quantify more tightly. Worth reading if you care about TDE outflows; not required if you do not.","headline":"Solid multi-year radio campaign on an unusually energetic thermal TDE; the state-transition conclusion is plausible but rests on a free-expansion launch-date choice that the paper itself flags as uncertain.","tokens_in":26542,"tokens_out":582,"would_cite":true,"duration_ms":7560,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.5","headline":"Radio data show AT 2022wtn launched a delayed, unusually fast and energetic non-relativistic outflow that only matches an accretion-disk state transition.","keywords":["tidal disruption events","radio astronomy","supermassive black holes","synchrotron equipartition","accretion disk state transition","outflows","circumnuclear medium"],"falsifier":"A denser early radio light curve or independent multiwavelength timing that forces the launch date to be much earlier or much later than day 138, or a clear free-free absorption signature that removes the need for a delayed launch, would change the derived velocity and energy enough to reopen the excluded outflow models.","tokens_in":26519,"feed_emoji":"📡","tokens_out":925,"duration_ms":9560,"temperature":0.7,"pith_summary":"AT 2022wtn is a tidal disruption event whose radio emission brightened months after optical discovery and stayed luminous for years. Multi-frequency VLA and GMRT observations, interpreted with an updated equipartition analysis under both spherical and conical geometries, yield a sub-relativistic outflow with velocity roughly 0.21c (spherical) or 0.41c (conical) and kinetic energy of order 10^49–10^50 erg. These numbers sit well above those of ordinary unbound debris streams, collisionally induced outflows, or accretion winds, while an on-axis relativistic jet is ruled out by luminosity, light-curve shape, and an unphysically narrow opening angle. The only mechanism that simultaneously accounts for the delayed launch, high speed, and high energy is an outflow driven by a later state transition in the newly formed accretion disk. The result places AT 2022wtn at the energetic extreme of non-relativistic radio TDEs and underscores that these events can launch outflows with a wide range of properties.","feed_headline":"TDE AT 2022wtn launched a 0.2c outflow from a disk state change","feed_subtitle":"Radio equipartition shows energy and speed too high for debris, winds, or jets","key_machinery":"Updated equipartition analysis of the radio spectral peak (radius and energy from peak frequency and flux under assumed spherical or conical filling factors), which converts the observed SEDs into physical velocity, kinetic energy, magnetic field, and ambient density.","core_discovery":"Only an accretion-disk state-transition outflow is consistent with the equipartition energy (~3.8\times10^49 erg spherical; ~1.8\times10^50 erg conical) and velocity (v≈0.21c spherical; ≈0.41c conical) derived for AT 2022wtn; relativistic jets, unbound debris, collisionally-induced outflows, and ordinary accretion winds are ruled out.","pith_inferences":["If state-transition outflows are common, a substantial fraction of the late-time radio TDE population may be powered by the same delayed-accretion mechanism rather than by prompt debris or winds.","The high ambient densities inferred near the black hole imply that circumnuclear gas in merging hosts can remain dense enough to produce luminous radio emission even at large radii.","A single multi-epoch radio campaign that samples both the free-expansion and decelerating phases can already discriminate among the main competing outflow models without requiring X-ray or gamma-ray detections."],"forward_implications":["Non-relativistic radio TDEs can reach kinetic energies and speeds previously associated only with the most powerful thermal events, expanding the known range of outflow properties.","Delayed radio brightening can be a direct signature of a later accretion-disk state transition rather than of unbound debris or prompt winds.","Both spherical and mildly collimated geometries remain viable; distinguishing them requires better constraints on opening angle or ambient density.","Long-term multi-frequency radio monitoring is essential for catching state-transition outflows that appear months after the optical peak."],"fun_headline_variants":["AT 2022wtn radio data show 0.21c outflow from disk state transition","Only disk state-change fits AT 2022wtn energy ~3.8e49 erg and speed","AT 2022wtn's 0.2c outflow rules out debris, winds and relativistic jets","Equipartition reveals AT 2022wtn as uniquely powerful non-rel TDE outflow","Conical model: AT 2022wtn drives 0.41c outflow via accretion state switch"],"cache_read_input_tokens":16512,"weakest_assumption_plain":"The outflow was launched near day 138 after optical discovery and stayed in free expansion long enough that a linear radius-versus-time fit correctly recovers that launch date and the resulting velocity.","fun_headline_variants_meta":{"raw":{"variants":["AT 2022wtn radio data show 0.21c outflow from disk state transition","Only disk state-change fits AT 2022wtn energy ~3.8e49 erg and speed","AT 2022wtn's 0.2c outflow rules out debris, winds and relativistic jets","Equipartition reveals AT 2022wtn as uniquely powerful non-rel TDE outflow","Conical model: AT 2022wtn drives 0.41c outflow via accretion state switch"]},"model":"grok-4.5","effort":"low","cost_usd":0.009386,"raw_usage":{"total_tokens":2179,"prompt_tokens":874,"num_sources_used":0,"completion_tokens":130,"cost_in_usd_ticks":93860000,"prompt_tokens_details":{"text_tokens":874,"audio_tokens":0,"image_tokens":0,"cached_tokens":128},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":1175,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":874,"tokens_out":130,"duration_ms":10626,"temperature":1.0,"reasoning_tokens":1175,"cache_read_input_tokens":128,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-07-10T21:31:36.184542+00:00","model_set":{"reader":"grok-4.5"},"falsifier":"A denser early radio light curve or independent multiwavelength timing that forces the launch date to be much earlier or much later than day 138, or a clear free-free absorption signature that removes the need for a delayed launch, would change the derived velocity and energy enough to reopen the excluded outflow models.","supporting_citations":[],"review_version":1}