{"id":"9a2db65d-75a8-4e93-8d4f-00be430ad9af","arxiv_id":"2607.13023","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":2,"one_line_summary":"Convection in red-supergiant envelopes can dominate accreted angular momentum and drive intermittent wobbling jets around neutron-star or black-hole companions in common-envelope evolution.","lead":"A 3D red-supergiant model shows that envelope convection can give accreted gas a randomly directed angular-momentum component several times larger than the orbital contribution. That can form intermittent, wobbling accretion disks and jets around compact companions during common-envelope evolution.","discovery_kind":"extension","skeptic_critique":{"model":"grok-4.5","headline":"The undisturbed non-rotating RSG idealization is load-bearing: companion stirring during CEE can reorder both fixed and stochastic angular-momentum components, potentially reversing the claimed hierarchy that enables intermittent disks around NS/BH companions.","rationale":"The reader already isolated the undisturbed-envelope idealization as the weakest structural premise and correctly set UNVERDICTED given the abstract-only status. No stronger internal inconsistency is visible from the abstract alone; the result is presented as a simulation measurement rather than a tautology, and the claim is within-field and potentially useful if the hierarchy survives feedback. The concrete test above simply operationalizes the same concern so that, once methods and data appear, one can decide whether the idealization is benign or fatal to the disk-formation conclusion. Hence the verdict remains UNVERDICTED and no adjustment is required.","tokens_in":2124,"tokens_out":488,"duration_ms":12164,"concrete_test":"When the full model is available, re-extract the accreted specific-angular-momentum time series after imposing a companion-driven velocity perturbation of order the local orbital speed inside a few Bondi–Hoyle radii (or a short companion-in-envelope run); if the stochastic-to-fixed j ratio drops below ~1 for NS/BH masses, the intermittent-disk claim weakens.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim (stochastic specific angular momentum several times the fixed-axis component, easily forming intermittent disks/jets around NS/BH but only marginally around MS stars) is measured on an undisturbed, non-rotating 3D RSG model that explicitly omits the companion’s dynamical influence (abstract). In actual CEE the companion drives spiral shocks, local shear, and envelope spin-up on orbital timescales. These ordered flows can (i) amplify the fixed-direction j component via steeper density gradients or coherent streaming and (ii) reorganize or suppress the convective velocity field that supplies the stochastic component. Because the paper reports only the no-feedback case, there is no quantitative bound showing that the stochastic/fixed ratio remains ≳ few once feedback is restored; if the ratio falls below ~1 for compact companions the intermittent-disk and wobbling-jet conclusions do not follow.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.5","summary":"The manuscript uses a newly constructed three-dimensional red-supergiant (RSG) stellar model (including nuclear energy production and photospheric emission) to measure the specific angular momentum of mass that a companion would accrete during common-envelope evolution (CEE). It separates a fixed-direction component, arising from the envelope density gradient and orbital motion, from a stochastically directed component driven by vigorous convection. Under the explicit idealization of an undisturbed, non-rotating RSG with no companion feedback, the fluctuating amplitude is reported to be several times the fixed-axis component. The authors conclude that intermittent accretion disks (and therefore wobbling jets) form readily around neutron-star or black-hole companions but only marginally or not at all around main-sequence companions, and they discuss implications for jets in CEE and grazing envelope evolution (GEE).","tokens_in":2343,"tokens_out":932,"duration_ms":20916,"significance":"If the reported hierarchy of stochastic versus fixed angular momentum holds under more realistic CEE conditions, the work would strengthen the case that jets are a standard ingredient of CEE/GEE and would specifically predict wobbling rather than fixed-axis jets. The differential, falsifiable prediction for compact versus main-sequence companions is scientifically useful. Use of a 3D RSG model that self-consistently includes nuclear energy production and photospheric emission is a methodological strength relative to purely analytic estimates of convective angular momentum.","major_comments":[{"comment":"The central quantitative claim—that fluctuating specific angular momentum is several times the fixed-axis component and therefore readily forms intermittent disks around NS/BH companions—is obtained under the explicit idealization of an undisturbed, non-rotating RSG envelope with no companion dynamical influence. In actual CEE the companion drives spiral shocks, local shear, and envelope spin-up on orbital timescales; these ordered flows can amplify the fixed-direction j component and reorganize or suppress the convective field that supplies the stochastic component. Because the paper reports only the no-feedback case, there is no quantitative bound showing that the stochastic/fixed ratio remains of order a few once feedback is restored. If the ratio falls below ~1 for compact companions, the intermittent-disk and wobbling-jet conclusions do not follow. This assumption is load-bearing an","section":"Abstract (methodology statement)"},{"comment":"The accretion sampling radius and mass-selection criterion are not specified in the available text. The measured specific angular momentum depends sensitively on the radial shell from which mass is drawn and on how accreted mass is defined. Without these choices (and associated resolution/convergence tests), the numerical factor “several times” and the NS/BH versus main-sequence disk-formation thresholds cannot be assessed for robustness. The full manuscript must document the sampling procedure, the companion mass and orbital parameters assumed when converting j to a disk-formation criterion, and any sensitivity tests.","section":"Abstract (accretion measurement)"}],"minor_comments":[{"comment":"Phrases such as “several times,” “easily forms,” and “marginally sufficient” should be replaced by explicit numerical ratios of j_stoch/j_fixed and by comparison to the Keplerian specific angular momentum at the companion surface (or ISCO for BHs) once full results are presented.","section":"Abstract"},{"comment":"A brief, self-contained definition of the grazing envelope evolution (GEE) regime assumed would help readers outside the authors’ prior series.","section":"Abstract (discussion of GEE)"},{"comment":"Clarify whether the 3D RSG model and analysis scripts are publicly available or documented for reproducibility.","section":"Abstract (model description)"}],"recommendation":"major_revision","confidential_remarks":"Only the abstract was available for this review; methods, resolution, error bars, and tables could not be checked. The paper continues a series advocating jets in CEE; independent scrutiny of the numerical methodology and of the undisturbed-envelope idealization is warranted. If the full manuscript already contains a quantitative bound on companion-feedback effects, the first major comment can be downgraded."},"author_rebuttal":null,"desk_editor":{"model":"grok-4.5","letter":"The one thing to know: this is an abstract-only report of a 3D RSG simulation that measures the stochastic angular-momentum component of accreted mass and finds it can be several times the fixed-axis piece from density gradient plus orbit. That hierarchy would let intermittent disks (and therefore wobbling jets) form easily around NS/BH companions and only marginally around main-sequence ones. If the numbers survive the full paper, it is a concrete, within-field result that CEE/GEE modelers should absorb.\n\nWhat is new is the quantitative comparison itself, extracted from their newly built 3D RSG that also mimics nuclear energy and photospheric emission. Prior work has treated jets and convection separately; putting a relative amplitude on the two j components is the actual contribution. The framing is clear and the claim is falsifiable once methods and figures appear. Credit where due: they state the idealization up front rather than hiding it.\n\nThe soft spot is exactly the one the stress-test flags, and it is not minor. They deliberately omit the companion’s dynamical influence and use an undisturbed, non-rotating envelope. In real CEE the companion drives spiral shocks, shear, and spin-up; those ordered flows can boost the fixed-direction j and reorganize the convective field that supplies the stochastic piece. Without a quantitative bound showing the stochastic/fixed ratio stays ≳ few once feedback is restored, the intermittent-disk and wobbling-jet conclusions for compact objects rest on an untested idealization. Free parameters (accretion sampling radius, internal model knobs) are also invisible from the abstract alone, so soundness cannot be scored higher than provisional.\n\nThis is for people who already work on CEE, GEE, and jet feedback in massive binaries. A serious referee should see the full paper: the measurement is interesting enough and the group’s prior RSG model is a real tool. I would not cite from the abstract alone, and I would not bring it to reading group until the methods and error bars exist. Send it to peer review if the full text supplies resolution studies, accretion-radius choices, and at least a discussion of how companion stirring might change the ratio; otherwise it is still a useful order-of-magnitude estimate but not yet load-bearing.","headline":"Abstract-only claim that convective j_stoch can dominate fixed-axis j in an undisturbed RSG, enabling intermittent disks/wobbling jets around NS/BH; useful if the full run holds, but the no-companion idealization is load-bearing and currently unchecked.","tokens_in":2954,"tokens_out":586,"would_cite":false,"duration_ms":5600,"reading_group":"no","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.5","headline":"Convective fluctuations in red-supergiant envelopes can dominate accreted angular momentum, forming intermittent disks and wobbling jets around compact companions.","keywords":["common envelope evolution","red supergiant","convection","accretion disks","wobbling jets","grazing envelope evolution","angular momentum","stellar companions"],"falsifier":"A three-dimensional hydrodynamical common-envelope simulation that includes both vigorous envelope convection and a live companion, checking whether the stochastic-to-fixed angular-momentum ratio remains of order several and whether intermittent disks still form around compact objects.","tokens_in":2979,"feed_emoji":"⭐","tokens_out":561,"duration_ms":4428,"temperature":0.7,"pith_summary":"This paper argues that when a companion spirals through a red-supergiant envelope, the gas it accretes carries not only the usual fixed-direction angular momentum set by the density gradient and orbital motion, but also a large, randomly directed component generated by the star’s vigorous convection. Using a three-dimensional red-supergiant model that includes energy production and surface emission, the authors show that the fluctuating piece can be several times larger than the fixed piece. The resulting total specific angular momentum is therefore enough to form intermittent accretion disks around neutron stars or black holes, which then launch jets whose axes wander. Around ordinary main-sequence companions the same angular momentum is only marginal, so disks form less readily. The work therefore supplies a concrete physical reason why jets launched during common-envelope evolution (or the preceding grazing-envelope phase) should be wobbling rather than steady, reinforcing the view that jets are an essential ingredient of the process.","feed_headline":"Convective red-supergiant gas launches wobbling jets in common envelopes","feed_subtitle":"Stochastic angular momentum can exceed the orbital piece by several times, forming intermittent disks around compact stars.","key_machinery":"A newly constructed three-dimensional red-supergiant model that self-consistently includes nuclear energy generation and photospheric emission, used to extract both the fixed-direction and the stochastically varying angular-momentum components of accreted envelope mass.","core_discovery":"The stochastic specific angular momentum supplied by red-supergiant convection can exceed the fixed-axis component by a factor of several, so that mass accreted onto a neutron-star or black-hole companion readily forms intermittent disks and launches wobbling jets; the same angular momentum is only marginally sufficient for main-sequence companions.","pith_inferences":[],"forward_implications":[],"fun_headline_variants":["RSG convection yields intermittent disks and wobbling jets in CEE","Stochastic RSG angular momentum forms wobbling jets around compact stars","Vigorous envelope convection launches wobbling jets during common-envelope evolution","Convective spin-up makes intermittent disks around NS and BH companions","Red-supergiant convection drives wobbling jets via intermittent accretion disks"],"cache_read_input_tokens":2304,"weakest_assumption_plain":"The calculation treats an undisturbed, non-rotating red-supergiant envelope and deliberately omits any dynamical stirring or spin-up that the companion itself would impose during common-envelope evolution.","fun_headline_variants_meta":{"raw":{"variants":["RSG convection yields intermittent disks and wobbling jets in CEE","Stochastic RSG angular momentum forms wobbling jets around compact stars","Vigorous envelope convection launches wobbling jets during common-envelope evolution","Convective spin-up makes intermittent disks around NS and BH companions","Red-supergiant convection drives wobbling jets via intermittent accretion disks"]},"model":"grok-4.5","effort":"low","cost_usd":0.003822,"raw_usage":{"total_tokens":1195,"prompt_tokens":837,"num_sources_used":0,"completion_tokens":95,"cost_in_usd_ticks":38220000,"prompt_tokens_details":{"text_tokens":837,"audio_tokens":0,"image_tokens":0,"cached_tokens":0},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":263,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":837,"tokens_out":95,"duration_ms":3684,"temperature":1.0,"reasoning_tokens":263,"cache_read_input_tokens":0,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-07-15T01:28:54.269906+00:00","model_set":{"reader":"grok-4.5"},"falsifier":"A three-dimensional hydrodynamical common-envelope simulation that includes both vigorous envelope convection and a live companion, checking whether the stochastic-to-fixed angular-momentum ratio remains of order several and whether intermittent disks still form around compact objects.","supporting_citations":[],"review_version":1}