{"id":"f694acb6-3cde-4e8a-a499-99f393d49397","arxiv_id":"2502.03730","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":3,"one_line_summary":"Massive galaxies within about 11 Mpc of cosmic filaments align their optical major axes with the filaments, and their radio jets become more randomly oriented relative to the host within about 8 Mpc.","lead":"Using radio and optical survey data, this paper measures how the shapes of massive galaxies and the directions of their AGN jets relate to the cosmic web of filaments. It finds that near filaments, galaxies align with the filament direction, while jets become less aligned with their host galaxies, suggesting chaotic accretion in dense environments.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Jet-randomization signal near filaments rests on a post-hoc |epsilon|>0.1 subsample, a two-sample KS p=0.036, no ellipticity control and no multiple-comparison correction; this is the least secure pillar of the abstract.","rationale":"The reader's verdict of conditional acceptance already includes the jet result's marginal significance and the untested spectroscopic-selection assumption. I agree with those concerns, but I would rank the statistical fragility of the jet-randomization signal as the single most load-bearing issue. The abstract's central claim couples two findings, and the second finding is the one that makes the paper distinctive: chaotic accretion near filaments scrambling AGN jet directions. That finding rests on a single two-sample KS p=0.036 in a subsample selected after inspecting the ellipticity trend, with no demonstrated control for the |epsilon_opt| distribution across Dfil and no multiple-comparison correction. The untested spec-z assumption is legitimate and should be checked, but even a perfectly unbiased spec-z sample would not rescue a p=0.036 post-hoc result. The galaxy-filament alignment, in contrast, has stronger internal significance and is consistent with earlier work, so the verdict does not need to move from conditional acceptance. My recommended test would settle whether the jet-randomization signal survives matched ellipticity distributions and correction for threshold searches; if it does not, the paper should be revised to present that result as tentative rather than as a headline claim.","tokens_in":26967,"tokens_out":7842,"duration_ms":89007,"concrete_test":"Match the |epsilon_opt| distribution between the Dfil<=7.98 Mpc and Dfil>7.98 Mpc bins within the EJ |epsilon_opt|>0.1 subsample (e.g., nearest-neighbor matching or quantile binning), then re-run the two-sample KS test and the misaligned-fraction comparison. Simultaneously, run a permutation procedure that recomputes the KS statistic for all plausible Dfil split points and ellipticity thresholds and compares the observed p=0.036 against the null distribution of the minimum p-value, thereby correcting for the post-hoc selections. If either test leaves p>0.05 or the misaligned-fraction difference within 1 sigma, the jet-randomization claim should be treated as unsupported pending larger and pre-registered samples.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The paper's most distinctive and physically novel claim is that radio jets become more randomly oriented with respect to their host galaxies within ~8 Mpc of cosmic filaments. This claim is the load-bearing part of the abstract, whereas the galaxy-filament alignment has prior observational support and stronger p-values (p=0.00073 in the innermost Dfil bin). The jet-randomization result is built on a post-hoc analysis chain: after Fig. 8 shows a strong dependence of the jet-galaxy angle on optical ellipticity, the analysis restricts to |epsilon_opt|>0.1 and then splits at Dfil=7.98 Mpc, a boundary evidently chosen from the same data. The only reported significance is a two-sample KS p=0.036, while the misaligned-fraction difference (60.2% vs 56.2%) is within about one sigma. No correction is applied for multiple Dfil bins or for the data-driven threshold selection. Furthermore, Fig. 8 shows that the jet-galaxy angle distribution depends strongly on |epsilon_opt| even across the full EJ sample, yet the paper does not display the |epsilon_opt| distribution as a function of Dfil. If galaxies near filaments have a different mean ellipticity within the >0.1 subsample, that alone could produce the apparent randomization. The Section 2.4 assertion that spectroscopic-redshift availability is independent of Dfil and orientation is also untested, but the jet result would be fragile even under that assumption, so the statistical and confounding issue is the more immediate threat to the central claim.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper uses LoTSS DR2 radio sources with spectroscopic redshifts, DESI Legacy imaging shapes, and the Malavasi et al. (2020) SDSS filament catalogue to study alignments between optical major axes, radio jet position angles, and the nearest cosmic filaments. It reports two main findings: (i) for massive galaxies (log M*/M_sun > 11), the optical major axis tends to align with the nearest filament for D_fil < ~11 Mpc, with a one-sample KS p-value of 0.00073 in the innermost bin; and (ii) radio jets are generally perpendicular to the host galaxy major axis, but this preference weakens within D_fil < ~8 Mpc, based on an |epsilon_opt| > 0.1 subset of the extended-jet sample. The results are interpreted as evidence for filament-directed merger-driven growth and chaotic accretion onto supermassive black holes near filaments.","tokens_in":27238,"tokens_out":4212,"duration_ms":41910,"significance":"If both claims hold, the paper provides a direct observational link between cosmic-web environment, galaxy shapes, and AGN jet orientations, with implications for intrinsic alignments, large-scale jet alignment searches, and anisotropic CGM/feedback models. The galaxy-filament alignment is the more secure result: it is supported by strong p-values, bootstrap skewness errors, and explicit projection-effect checks, and it builds on prior observational and simulation work. The jet-randomization claim is more novel but is the least secure pillar of the paper. The analysis uses appropriate statistical machinery (parallel transport, KS tests, bootstrap resampling), real survey data, and includes explicit checks of contributing systematics; however, no analysis code is provided, and the Section 2.4 assertion about selection independence is untested.","major_comments":[{"comment":"The assertion that requiring a spectroscopic redshift \"does not affect the results that will follow\" is presented without a supporting test. If the completeness of spectroscopic redshifts in the LoTSS cross-match catalogue varies with distance to the nearest SDSS filament (e.g., because dense regions have more SDSS spectroscopy) or with galaxy/radio orientation, the D_fil distributions of the GMRG and EJ samples would be biased, and both the galaxy-filament and jet-galaxy-filament signals could be generated or suppressed. Please add a quantitative comparison of the photometric/spec-z samples or an explicit robustness test, and weaken the claim if no test is possible.","section":"Section 2.4"},{"comment":"The central new claim that jets become more randomly oriented relative to their host galaxies within ~8 Mpc of filaments rests on a post-hoc analysis chain. After Fig. 8 shows a strong dependence of the jet-galaxy angle on |epsilon_opt|, the sample is cut at |epsilon_opt| > 0.1 and split at D_fil = 7.98 Mpc, with a two-sample KS p = 0.036 and a misaligned-fraction difference (60.2% vs 56.2%) whose 1-sigma errors overlap. No correction is made for the multiple D_fil bins or for the data-driven threshold selection. In addition, the paper does not display the |epsilon_opt| distribution as a function of D_fil; since Fig. 8 establishes that the jet-galaxy angle depends strongly on |epsilon_opt|, a D_fil-dependent ellipticity within the >0.1 subsample could by itself produce the apparent randomization. Please provide (i) the |epsilon_opt| versus D_fil distribution, (ii) a continuous analysis using the full EJ sample without post-hoc cuts, or a pre-specified split at a physically motivated scale, and (iii) a multiple-comparison adjustment or an explicit statement of the number of splits examined.","section":"Section 3.2, Fig. 9"},{"comment":"The abstract's phrasing \"radio jets ... show more randomised orientations with respect to host galaxies within ≲ 8 Mpc of filaments\" is stronger than the evidence in Fig. 9 supports. The one-sample KS tests in all D_fil bins reject uniformity, the two-sample KS p is 0.036, and the effect is only present in an ellipticity-selected subset. The conclusion should be tempered or the statistics strengthened before publication.","section":"Abstract / Summary"}],"minor_comments":[{"comment":"There is a typo in the abstract: \"activegalactic nuclei\" should be \"active galactic nuclei\".","section":"Abstract"},{"comment":"The definition of PA_fil uses a two-argument arctangent without specifying the quadrant convention; please clarify how the angle is wrapped to [0,180) degrees.","section":"Section 2.3, Eq. (7)"},{"comment":"The EJ sample criteria mention the 'E_PA' column for S_Code='M' sources, but this column is not defined in the text; a brief definition would help reproducibility.","section":"Section 2.4"},{"comment":"The reference for Springel et al. (2005) lists the journal as \"Nature Astrophysics\" rather than \"Nature\"; please correct.","section":"References"},{"comment":"The statement that parallel transport alters position angles by ~3 degrees on average is useful, but Fig. 5 shows individual corrections exceeding 10 degrees; please clarify whether the mean is the relevant quantity for the reported alignment signal.","section":"Section 3.1.1, Fig. 5"},{"comment":"No analysis code is provided; for reproducibility, please link the scripts used for the KS tests, bootstrap skewness, and sample construction.","section":"Data Availability"}],"recommendation":"major_revision","confidential_remarks":"The galaxy-filament alignment result is solid enough to be publishable, and the paper is clearly written with appropriate statistical tools. The jet-randomization claim, which is the most novel and abstract-driving result, is currently too fragile: it depends on a post-hoc ellipticity cut, a data-chosen D_fil split, and a single marginal p-value, with no demonstration that ellipticity is balanced across D_fil. The Section 2.4 spectroscopic-completeness assumption is also untested and could affect both analyses. I would encourage the authors to add the requested robustness tests and either strengthen the jet claim or soften the abstract accordingly."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The genuinely new thing here is the first comparison of radio jet orientations with 3D cosmic filaments, and the paper is honest enough to show that the two halves of the abstract are not equally strong. The galaxy-filament alignment is solid: massive galaxies within ~11 Mpc of filaments have optical major axes aligned with the filament, strongest at <6 Mpc, and the signal increases with optical ellipticity and decreases with filament inclination exactly as a real physical alignment should. The p-values in the inner bins (0.00073 and 0.0145) and the two-sample KS p=0.002 support it. The parallel transport treatment is careful, and the bootstrap skewness errors look right.\n\nThe soft spot is the second claim, that radio jets become more randomly oriented with respect to their host galaxies within ~8 Mpc of filaments. The analysis restricts to |eps_opt|>0.1 after Fig. 8 shows a strong ellipticity dependence, splits at 7.98 Mpc using the same data, and reports a two-sample KS p=0.036. The misaligned fraction difference (60.2% vs 56.2%) is within about one sigma. No multiple-comparison correction is applied across Dfil bins. Crucially, the paper never shows the |eps_opt| distribution as a function of Dfil. Since the jet-galaxy angle distribution changes sharply with |eps_opt|, a mild environmental difference in ellipticity near filaments could produce this signal without any physical jet-filament connection. That is a real confounding path, and the stress-test note is right to single it out.\n\nA separate concern is the Section 2.4 assertion that spectroscopic-redshift availability is independent of filament proximity and orientation. That is load-bearing and untested. If spec-z completeness is higher in dense filamentary regions, the Dfil distributions are biased and both results could be affected, though I would expect the galaxy-filament alignment to survive given its internal consistency.\n\nThere is no circularity problem: the alignment statistics come from external catalogues and no fitting is done to manufacture the signal.\n\nWho is this for: people working on intrinsic alignments, AGN feedback geometry, or the large-scale orientation of radio jets. It deserves a serious referee, not a desk reject. I would ask for: (1) the |eps_opt| distribution versus Dfil within the selected subsample, (2) a spec-z completeness check as a function of Dfil and position angle, (3) an acknowledgment or correction for multiple comparisons, and (4) ideally a distance split motivated before looking at the data. Conditional acceptance is the right call.","headline":"New and worth reading, but the jet-randomization half of the abstract rests on a post-hoc subsample and a p=0.036; the galaxy-filament alignment is the solid half.","tokens_in":27851,"tokens_out":2109,"would_cite":true,"duration_ms":22204,"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":"The cosmic web imprints on galaxies: near filaments, massive galaxies align with the filament while their radio jets point more randomly.","keywords":["galaxies: evolution","galaxies: jets","large-scale structure of Universe","methods: observational","cosmic filaments","radio galaxies","intrinsic alignment","AGN feedback"],"falsifier":"Use a spectroscopic sample whose completeness does not vary with filament proximity, for example a magnitude-limited survey covering the same volume, and recompute the skewness of the galaxy-filament angle distribution in the $D_{\\rm fil} \\le 6\\,\\mathrm{Mpc}$ bin and the misaligned-jet fraction in the $D_{\\rm fil} \\le 8\\,\\mathrm{Mpc}$ bin. If the positive skewness and the excess of misaligned jets disappear, the claimed environmental imprint is a selection artifact rather than a physical alignment.","tokens_in":26740,"feed_emoji":"🌌","tokens_out":10115,"duration_ms":124048,"temperature":0.7,"pith_summary":"The paper aims to establish that the cosmic web leaves a direct, measurable imprint on both the shapes of massive galaxies and the directions of their radio jets. Combining the LoTSS DR2 radio survey, DESI Legacy optical imaging, and an SDSS-derived filament catalogue, it reports that galaxies with stellar mass above $10^{11}\\,\\mathrm{M_\\odot}$ within about $11\\,\\mathrm{Mpc}$ of the nearest filament tend to have their optical major axes aligned with the filament, with the strongest signal within about $6\\,\\mathrm{Mpc}$. It also reports that radio jets, which are generally perpendicular to the host galaxy's major axis, become more randomly oriented relative to the host within about $8\\,\\mathrm{Mpc}$ of a filament. The authors interpret this pair of results as evidence that filament-directed mergers build up massive galaxies while feeding the central black hole chaotically, which would explain why coherent large-scale radio jet alignments are weak and why AGN feedback in filaments should act preferentially along dark-matter-halo minor axes.","feed_headline":"Cosmic filaments align galaxies and scramble jets","feed_subtitle":"Within ~11 Mpc, massive galaxies line up along filaments; within ~8 Mpc, their radio jets aim more randomly.","key_machinery":"The analysis compares three orientation vectors: the optical major axis from DESI Legacy ellipticity components, the radio jet position angle from LoTSS DR2 (deconvolved Gaussian position angle or composite-source convex-hull angle), and the local orientation of the nearest segment of an SDSS DR12 filament catalogue. Distances to filaments are computed in 3D Cartesian coordinates, and because a galaxy and its closest filament sampling point can be separated on the sky, position angles are parallel-transported along the great circle connecting the two locations before the dot product is taken. The statistical workhorse is the skewness of the resulting angle distributions, with one- and two-sample Kolmogorov-Smirnov tests used to compare each distribution against uniformity and against other distance bins.","core_discovery":"The paper's central claim is that distance to the nearest cosmic filament is a controlling variable for galaxy and jet orientations. For the GMRG sample of 84,409 massive radio galaxies with spectroscopic redshifts, the angle between the optical major axis and the nearest filament is not uniform within $D_{\\rm fil} \\le 6.36\\,\\mathrm{Mpc}$: it is positively skewed toward $0^\\circ$ (one-sample KS $p = 0.00073$), and a two-sample KS test separates the inner bin from the rest of the sample at $p = 0.002$. The alignment persists in the $6.36\\!-\\!10.96\\,\\mathrm{Mpc}$ bin ($p = 0.0145$) and disappears beyond $\\sim 11\\,\\mathrm{Mpc}$, and it is stronger for higher-ellipticity galaxies and for filaments with lower line-of-sight inclination. For the extended jet subsample with $|\\epsilon_{\\rm opt}| > 0.1$, the usual preference for jets to lie perpendicular to the galaxy major axis is diluted at $D_{\\rm fil} \\le 7.98\\,\\mathrm{Mpc}$: the misaligned-jet fraction is about $60\\%$ there versus about $56\\%$ at larger distances, and a two-sample KS test gives $p = 0.036$. The paper takes these results as evidence that massive galaxies in filaments grow by mergers channeled along the filament, while chaotic gas accretion onto the black hole randomizes jet directions, so AGN feedback is preferentially deposited along halo minor axes inside filaments.","pith_inferences":["Going beyond the paper, a natural next test is to split filament galaxies by merger stage: the merger-alignment picture predicts stronger galaxy-filament alignment and stronger jet randomization in galaxies with tidal features or close companions.","Because the extended jet sample is restricted to luminous, large radio sources, the chaotic-accretion interpretation could be probed with fainter or younger jets, which should show an even stronger distance-from-filament dependence if reorientation is frequent.","The quoted scales of about $11\\,\\mathrm{Mpc}$ and $8\\,\\mathrm{Mpc}$ are tied to one filament finder's definition; comparing with filament catalogues built from velocity-shear or tidal-field criteria would show how much of the signal is definition-dependent."],"forward_implications":["If the central claim is right, cosmic shear surveys must treat galaxies within about $11\\,\\mathrm{Mpc}$ of filaments as intrinsically aligned with the filament, rather than randomly oriented, which biases weak-lensing measurements in filament regions.","Searches for coherent large-scale radio jet orientations over tens of Mpc should expect weak or absent signals, because the filament environment acts to randomize jet directions rather than to align them.","AGN feedback in massive filament galaxies is preferentially deposited along the minor axes of their dark matter halos, making the circumgalactic medium around such galaxies anisotropic in an environment-dependent way.","The observed azimuthal segregation of blue and quenched satellite galaxies around cluster members can partly arise from filament-directed assembly and jet orientation established before infall, rather than only from in-cluster processes."],"supporting_citations":[{"why":"Supplies the LoTSS DR2 radio-optical cross-matched catalogue used to define the general massive radio galaxy and extended jet samples, with redshifts, stellar masses, and radio position angles.","marker":"Hardcastle et al. (2023)"},{"why":"Provides the LoTSS DR2 radio source catalogue and resolution criteria from which radio flux, angular size, and position angles are drawn.","marker":"Shimwell et al. (2022)"},{"why":"Provides DESI Legacy Imaging Surveys photometry and shape measurements used to derive optical position angles and ellipticities.","marker":"Dey et al. (2019)"},{"why":"Supplies the SDSS DR12 cosmic filament catalogue and sampling points used to compute three-dimensional distances and filament orientation vectors.","marker":"Malavasi et al. (2020)"},{"why":"Provides the SDSS DR12 galaxy data underlying the LOWZ+CMASS sample from which the filaments are constructed.","marker":"Alam et al. (2015)"},{"why":"Introduces the parallel transport formalism used to compare position angles when a galaxy and its closest filament point are separated on the sky.","marker":"Jain et al. (2004)"},{"why":"Establishes the baseline result that radio jets align with the optical minor axis and motivates the ellipticity-dependent jet-galaxy analysis.","marker":"Zheng et al. (2024)"},{"why":"Provides the simulation-based expectation that halos in filaments align via directional mergers, which the paper interprets its galaxy-filament alignment as supporting.","marker":"Kang & Wang (2015)"}],"fun_headline_variants":["Filaments align galaxies but scramble AGN jets","Cosmic filaments: galaxies align, jets go random","Filaments align galaxies, randomize radio jets","Filament proximity aligns galaxies, randomizes jets","Near filaments, galaxy axes align and jets scatter"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing premise is that the chance a galaxy has a spectroscopic redshift does not depend on how close it is to a cosmic filament or on how its galaxy and jet are oriented.","fun_headline_variants_meta":{"raw":{"variants":["Filaments align galaxies but scramble AGN jets","Cosmic filaments: galaxies align, jets go random","Filaments align galaxies, randomize radio jets","Filament proximity aligns galaxies, randomizes jets","Near filaments, galaxy axes align and jets scatter"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.00081,"raw_usage":{"total_tokens":3654,"prompt_tokens":1148,"completion_tokens":2506,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":764,"completion_tokens_details":{"reasoning_tokens":2434}},"tokens_in":764,"tokens_out":2506,"duration_ms":18283,"temperature":1.0,"reasoning_tokens":2434,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-09T00:57:14.295729+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Use a spectroscopic sample whose completeness does not vary with filament proximity, for example a magnitude-limited survey covering the same volume, and recompute the skewness of the galaxy-filament angle distribution in the $D_{\\rm fil} \\le 6\\,\\mathrm{Mpc}$ bin and the misaligned-jet fraction in the $D_{\\rm fil} \\le 8\\,\\mathrm{Mpc}$ bin. If the positive skewness and the excess of misaligned jets disappear, the claimed environmental imprint is a selection artifact rather than a physical alignment.","supporting_citations":[{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Establishes the baseline result that radio jets align with the optical minor axis and motivates the ellipticity-dependent jet-galaxy analysis."}],"review_version":1}