{"id":"e4a13749-811d-4cfa-a121-ab08c0a1887e","arxiv_id":"2507.06375","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":5.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":6,"one_line_summary":"iEDGE is a new 643-galaxy catalog of integrated CO and IFU data showing that passive galaxy centers have lower star formation efficiency relative to global values.","lead":"This paper presents iEDGE, a new catalog of molecular gas and star formation measurements for 643 nearby galaxies, combining optical IFU maps with CO observations from APEX, CARMA, and ACA. The data suggest that passive galaxies have central regions that are much less efficient at turning molecular gas into stars than their overall galaxy averages.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The passive-galaxy SFE offset may be an artifact of plotting CO upper limits as detections; survival analysis is required before the central claim can stand.","rationale":"The paper's headline result is the SFE offset in passive galaxies, and the weakest link in that argument is not the aperture correction alone but the fact that the low-SFE regime is populated by upper limits masquerading as detections. A survival analysis is the standard remedy and is implementable with the released data. Because both censoring and the 1-versus-2-dex discrepancy concern the central claim, I agree with the reader's CONDITIONAL verdict but would prioritize the censored-data treatment as the necessary condition for acceptance.","tokens_in":36216,"tokens_out":6932,"duration_ms":78630,"concrete_test":"Using the public iEDGE table on Zenodo, select E/S0 galaxies with Delta_SFMS<-1.5 and CO S/N<3. Recompute the SFE_B versus SFE_G comparison treating M_mol_B as left-censored (upper limit) data in a Bayesian censored regression, and report the posterior distribution of the median log(SFE_G/SFE_B). If the posterior is consistent with zero or below 0.5 dex, the 'strongly reduced central SFE' claim fails; if it remains at ~1 dex, the abstract and conclusions should be corrected from 'almost two orders of magnitude' to the measured value.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim depends on Fig. 9 showing SFE_B < SFE_G for E/S0 galaxies at Delta_SFMS < -1.5. However, the low-SFE tail in that figure is dominated by APEX non-detections (S/N<3), for which M_mol_B is entered as a 3-sigma upper limit. Because SFE = SFR/M_mol, these entries are lower limits on SFE_B, not measurements. Plotting them as points systematically depresses SFE_B and can create a spurious SFE_G/SFE_B offset even if the true central efficiency is comparable to the global value. The authors themselves caution in Section 4.5 that 'the low SFE tail of the distributions is dominated by non-detections' and that the SFE behaviour should be interpreted with caution. A second, independent inconsistency compounds this: the abstract states the offset is 'almost two orders of magnitude', the Fig. 9 caption says '~1 dex', and the conclusions say '~2 dex' for Delta_SFMS<-1.5. Until the censored data are treated with a survival-analysis or Bayesian upper-limit model, the existence and magnitude of suppressed central SFE in passive galaxies is not established. The WISE-aperture-correction concern raised by the reader is real, but its dominant effect would be on M_mol_G, and the direction of its bias is not obviously able to create the offset; the censoring issue can directly create it.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"This paper presents iEDGE, an integrated database of stellar, nebular, and molecular gas properties for 643 CALIFA galaxies, combining CALIFA IFU optical data with CARMA CO(1-0), ACA CO(2-1), and APEX CO(2-1) observations. The authors homogenize beam and global quantities via tapering, smoothing, and a WISE W3-based aperture correction (Eq. 4), and use the database to examine the SFR-M*, SFR-Mmol, and Mmol-M* relations. The headline result is that for early-type/passive galaxies below Delta_SFMS of about -1.5, the star formation efficiency in the inner regions is suppressed relative to the global SFE, while the molecular gas fraction remains roughly constant; the authors interpret this as evidence that inside-out quenching requires not only low f_mol but also strongly reduced SFE in galaxy centers. The paper also provides a public data release and a series of cross-telescope consistency checks.","tokens_in":36426,"tokens_out":5649,"duration_ms":59880,"significance":"If the central result holds, it would strengthen the case that quenching in galaxy centers is not solely due to gas depletion. The database itself is a substantial community resource: it is large, covers a broad range of SFR, stellar mass, and morphology, and the homogenization, tapering, and aperture-correction procedure is clearly described and benchmarked against overlapping observations. The paper ships a public Zenodo release and includes transparent flags for upper limits. These are genuine strengths. However, the central claim is not yet established because the treatment of censored CO non-detections and the internal inconsistency in the claimed magnitude are load-bearing and currently under-supported. I find no fundamental circularity in the analysis: the database measurements come from external observations, and the key calibrations are not defined in terms of the target result.","major_comments":[{"comment":"The paper states the central result with inconsistent magnitudes. The abstract says the inner-region SFE of passive galaxies is 'almost two orders of magnitude lower' than the global value; Section 5 repeats '~2 dex' for Delta_SFMS < -1.5; Section 4.5 says the inner regions form stars at a rate 'roughly 10 times lower', and the Fig. 9 caption says '~1 dex lower'. Because the size of this offset is the paper's headline and the basis for the inside-out-quenching interpretation, the authors must adopt a single, well-defined measurement (for example, the median of log(SFE_G) - log(SFE_B) over a specified Delta_SFMS and morphology selection) and use it consistently throughout.","section":"Abstract; Section 4.5; Fig. 9 caption; Section 5"},{"comment":"The apparent suppression of central SFE in passive galaxies is not separated from the treatment of CO non-detections. In the low-SFE tail, which the authors state is 'dominated by non-detections', M_mol_B is a 3-sigma upper limit, so SFE_B = SFR_B / M_mol_B is a lower limit rather than a measurement. Plotting these limits as points in the SFE_G versus SFE_B plane systematically displaces the passive-galaxy population toward low SFE_B and can create the reported offset even if the true central efficiencies are comparable to the global values. The central claim requires a survival-analysis or Bayesian upper-limit treatment, or at minimum a version of Fig. 9 restricted to S/N > 3 detections, before it can be taken as evidence for reduced central SFE. The caveat in the text is not sufficient because the abstract and conclusions do not carry this qualification.","section":"Section 4.5; Fig. 9"},{"comment":"The aperture correction used to estimate APEX global CO luminosities is calibrated on the WISE W3 relation and benchmarked against ACA and CARMA samples that are predominantly star-forming, late-type galaxies. No direct global CO validation exists for the passive early-type population that dominates the offset claim. Because SFE_G in Fig. 9 is computed with M_mol_G derived from Eq. 4, a systematic error in the aperture correction for quiescent objects could change the magnitude or even the direction of the apparent offset. The authors should either provide independent global CO constraints for a subsample of passive E/S0 galaxies (for example, wide-beam single-dish measurements) or demonstrate that the Fig. 9 result is robust to plausible alternative aperture corrections, including the directly measured ACA and CARMA global-to-beam ratios.","section":"Eq. 4; Section 3.1.3; Section 4.1"}],"minor_comments":[{"comment":"Section 5 states that beam measurements cover 'within 23.6 arc-seconds, or the APEX beam at 230 GHz', but the APEX beam FWHM is 26.3 arcsec in Section 2.4 and Section 3.1.1; 23.6 arcsec is the FWHM of the tapering Gaussian, not the APEX beam. Please correct this inconsistency.","section":"Section 5; Section 2.4; Section 3.1.1"},{"comment":"Equation 14 cites 'den Brok et al. (in prep.)' for the R21-Sigma_SFR relation, but no such work appears in the reference list (den Brok et al. 2021 and 2023 are listed). This calibration is central to the molecular gas mass scale and must be citable and reproducible.","section":"Eq. 14; References"},{"comment":"The figure uses transparent diamonds to indicate upper limits, but these limits are still plotted as point symbols in the SFE_B panel. Showing them as downward arrows or otherwise visibly different symbols would make the censorship status clearer and reduce the risk of readers misinterpreting lower limits as detections.","section":"Fig. 9"},{"comment":"The column name 'Observatory_Type_k2jypb' appears to be a garbled or placeholder name for a Jy/beam per K conversion factor; please rename it to something descriptive such as 'Observatory_Type_Jy_per_K'.","section":"Table C.1"},{"comment":"The sentence 'We used ACA data instead of APEX data in case the latter showed better S/N compared to the former' is ambiguous about which dataset is preferred in the consolidated sample; please rephrase to state explicitly the selection rule.","section":"Section 4.3.1"}],"recommendation":"major_revision","confidential_remarks":"The paper is best viewed as a data paper with an interpretive claim. The censoring issue is fixable with a survival analysis or a detection-only version of the key figure, and the magnitude inconsistency is easily corrected; these are within scope. The aperture-correction concern is harder to fully resolve with existing data, but it should at least be acknowledged as a systematic uncertainty in the headline result. I see no evidence of circularity or fabrication, and the self-citation pattern is typical for a survey paper, with the C20 taper being used appropriately. The database product itself is valuable and likely publishable after the revisions."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"You should know two things about this paper before reading it. First, the iEDGE database itself is a real contribution: 643 CALIFA galaxies with homogenized integrated CO measurements, 172 new APEX spectra, cross-calibrated against CARMA and ACA, and publicly released on Zenodo. Second, the central scientific claim—that the inner SFE of passive galaxies is strongly suppressed relative to global values—is not yet supported by the analysis as presented. The magnitude shifts between \"almost two orders of magnitude\" in the abstract, \"~2 dex\" in the conclusions, and \"~1 dex\" in the results and figure caption. That internal inconsistency alone would need fixing, but the deeper problem is worse.\n\nThe stress-test note is correct on the load-bearing point. The low-SFE tail of the passive galaxies is dominated by CO non-detections, for which M_mol is an upper limit, making SFE a lower limit. Plotting those lower limits as data points systematically drags SFE_B down and can manufacture the global-versus-beam offset even if the true central efficiency is normal. The authors themselves warn in Section 4.5 that the low-SFE tail is dominated by non-detections and that the SFE behavior should be interpreted with caution, yet that caution does not make it into the abstract. What is needed is a survival analysis or a Bayesian treatment of the upper limits; without it, the paper's headline result is not established. The WISE-based aperture correction for APEX global luminosities is a second, real concern, because the correction is benchmarked mostly on star-forming late-type galaxies, not on the passive population where the global SFE matters most. Its direction of bias is less clear, but it is another reason to treat the SFE_G versus SFE_B contrast cautiously.\n\nTo be fair: the database construction is transparent, the cross-telescope comparisons are careful, and the qualitative scaling-relation trends agree with prior resolved EDGE-CALIFA and ALMaQUEST work. The paper does not pretend more than it should about the aperture correction, and the data release is genuinely useful. The citations, including the heavy use of the collaboration's own C20, are appropriate given that iEDGE directly extends that work.\n\nWho should read this? Anyone doing integrated CO work on local galaxies or using CALIFA in the next few years will want the database. It deserves a serious referee because the resource is valuable, but the referee should insist on a survival-analysis treatment of the non-detections and a consistent statement of the claimed SFE offset. My recommendation: send it to review, with major revision focused on the censored-data issue, and do not let the abstract overstate what the current analysis supports.","headline":"iEDGE is a valuable public database, but the headline inside-out quenching claim rests on censored CO data and an internal magnitude inconsistency.","tokens_in":37165,"tokens_out":1914,"would_cite":true,"duration_ms":24018,"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":"Quenched galaxies do not just run out of molecular gas; their central regions also lose the ability to turn the gas they still have into stars, by about two orders of magnitude.","keywords":["galaxy evolution","molecular gas","CO emission","star formation efficiency","quenching","integral field spectroscopy","CALIFA survey","star-forming main sequence"],"falsifier":"Map the full CO(2-1) extent of a sample of passive E/S0 galaxies more than 1.5 dex below the star-forming main sequence with total-power or interferometric observations, and compare the directly measured global CO luminosities with the APEX aperture-corrected values; agreement around the expected factor of 1.7 would confirm the central SFE suppression, while a systematic offset would show it is an artifact of the correction.","tokens_in":35899,"feed_emoji":"🌌","tokens_out":9573,"duration_ms":91811,"temperature":0.7,"pith_summary":"This paper builds iEDGE, a homogenised database of integrated molecular-gas, star-formation, and stellar-mass measurements for 643 local galaxies from the CALIFA survey, combining optical integral-field data with CO observations from three telescopes. The authors use the database to test how galaxies shut down star formation as they move from the star-forming main sequence, through the green valley, and into the retired sequence. They find that the three classic scaling relations (SFR–$M_*$, SFR–$M_{\\rm mol}$, $M_{\\rm mol}$–$M_*$) are bimodal, cleanly separating star-forming spirals from passive early-type galaxies. The central result concerns the inner regions: while the molecular gas fraction $f_{\\rm mol}$ stays roughly constant from galaxy centres to discs, the star formation efficiency SFE in the cores of passive galaxies (those more than about 1.5 dex below the main sequence) is almost two orders of magnitude lower than the global value. This indicates that inside-out quenching requires not only low molecular gas fractions but also a strongly suppressed ability to turn molecular gas into stars in galactic centres.","feed_headline":"Quenching needs more than gas loss: galaxy cores stop forming stars","feed_subtitle":"New 643-galaxy CO database shows passive galactic centres form stars up to 100 times less efficiently than their discs.","key_machinery":"The carrying object is the iEDGE database itself, organised around a beam-versus-global split in every quantity. Beam quantities are measured within the 26.3-arcsec APEX beam; global quantities cover the full CALIFA footprint, roughly two effective radii. Three homogenisation techniques make the heterogeneous data comparable: tapering the CALIFA maps with a two-dimensional Gaussian to match the APEX beam, smoothing CARMA and ACA datacubes to APEX spatial and spectral resolution, and an aperture correction for the APEX single-pointing data, $\\log L^{\\rm APEX,G}_{\\rm CO(2-1)} = 0.08 + 1.02 \\log L^{\\rm APEX,B}_{\\rm CO(2-1)}$. That correction converts beam CO luminosities to global values by assuming that WISE W3 12-$\\mu$m luminosity measured in the same beam traces the CO flux lying outside the beam, and it is what produces the global quantities whose contrast with beam values defines the central SFE result.","core_discovery":"On the paper's own terms, the discovery is that passive early-type galaxies quench from the inside out through two channels working together. Using beam quantities (measured within the 26.3-arcsec APEX beam, roughly the inner one effective radius) and global quantities (integrated over the full galaxy), the paper shows that $f_{\\rm mol}=M_{\\rm mol}/M_*$ is spatially flat: beam and global molecular gas fractions scatter around the 1:1 relation across all morphological types. Star formation efficiency, SFE $=$ SFR/$M_{\\rm mol}$, behaves differently. In spiral, star-forming galaxies the beam and global SFEs agree, but in E/S0 galaxies more than about 1.5–2 dex below the star-forming main sequence, the inner SFE is roughly 10–100 times lower than the global value, producing a flattened SFE$_{\\rm global}$–SFE$_{\\rm beam}$ relation. The paper interprets this as a direct manifestation of inside-out quenching: removing molecular gas is not enough; galactic centres must also lose the capacity to form stars from the gas they retain. The authors add the caution that the global APEX quantities depend on an aperture correction, so the significance of the bending should be interpreted with care.","pith_inferences":["A testable extension: apply the same beam-versus-global decomposition to resolved CO maps of green-valley galaxies with $\\Delta_{\\rm SFMS}$ between −1.5 and −2 to determine whether the central SFE drop precedes or follows the drop in molecular gas fraction; the integrated sample cannot cleanly separate those two stages.","A validation experiment: add total-power CO(2-1) maps for the passive APEX-only targets in iEDGE; the existing overlap galaxies already test the aperture correction, but the passive population is exactly the one with no direct global-CO check.","If the central SFE suppression is physical, numerical simulations of galaxy formation that reproduce quenching through gas depletion alone may need an additional stabilisation or feedback term that acts preferentially in high-stellar-density centres.","The flatness of $f_{\\rm mol}$ centre-to-disc in passive galaxies hints that the residual molecular gas is not arranged in star-forming complexes; resolved CO observations could test whether it is diffuse or dynamically stabilised."],"forward_implications":["If the central claim is right, quenching models must include a mechanism that suppresses star formation efficiency by about two orders of magnitude in the centres of passive early-type galaxies, not only a mechanism that removes or heats molecular gas.","The bimodality of the SFR–$M_*$, SFR–$M_{\\rm mol}$, and $M_{\\rm mol}$–$M_*$ relations means an integrated molecular-gas measurement alone can tell whether a galaxy belongs to the star-forming or retired population.","Galaxies between about 1.5 and 2 dex below the main sequence mark the switch point where the inner SFE drops relative to the global value even though the molecular gas fraction remains spatially flat.","Because $f_{\\rm mol}$ is flat while SFE is not, future resolved surveys must measure both quantities simultaneously; a single global measurement cannot reveal which channel is quenching a galaxy.","The many CO non-detections among passive galaxies imply that the gas-removal channel may be even stronger than the measured molecular gas fractions indicate, since those values are upper limits."],"supporting_citations":[{"why":"Defines the earlier 472-galaxy dataset, the global-plus-beam framework, and the initial evidence that reduced central SFE drives quenching.","marker":"Colombo et al. (2020)"},{"why":"Supplies the CARMA CO(1-0) maps and smooth-masking fluxes used for the interferometric part of iEDGE.","marker":"Bolatto et al. (2017)"},{"why":"Provides the ACA CO(2-1) data, the SFR map construction method, and resolved EDGE-CALIFA comparisons.","marker":"Villanueva et al. (2024)"},{"why":"Provides the WISE W3 12-micron photometry from z0MGS that seeds the aperture correction.","marker":"Leroy et al. (2019)"},{"why":"Defines the star-forming main sequence used to compute the distance from the main sequence, $\\Delta_{\\rm SFMS}$.","marker":"Cano-Díaz et al. (2016)"},{"why":"Gives the metallicity- and density-dependent CO-to-H$_2$ conversion factor used to turn CO luminosities into molecular gas masses.","marker":"Bolatto et al. (2013)"},{"why":"Supplies the earlier CO(2-1)-to-12-micron relation against which the APEX-WISE calibration is compared.","marker":"Gao et al. (2019)"}],"fun_headline_variants":["Galaxy cores quench by losing efficiency, not just gas","Inside-out quenching: gas alone won't stop star formation","Star formation efficiency drops 100x in passive galaxy centers","New CO survey reveals why galaxy centers stop forming stars","Gas loss plus efficiency drop: recipe for galaxy quenching"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The headline result depends on the assumption that the 12-micron light from a galaxy's central beam region faithfully predicts the carbon-monoxide emission outside the beam for every galaxy type, including the passive early-type galaxies that drive the finding.","fun_headline_variants_meta":{"raw":{"variants":["Galaxy cores quench by losing efficiency, not just gas","Inside-out quenching: gas alone won't stop star formation","Star formation efficiency drops 100x in passive galaxy centers","New CO survey reveals why galaxy centers stop forming stars","Gas loss plus efficiency drop: recipe for galaxy quenching"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000604,"raw_usage":{"total_tokens":2922,"prompt_tokens":1154,"completion_tokens":1768,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":770,"completion_tokens_details":{"reasoning_tokens":1688}},"tokens_in":770,"tokens_out":1768,"duration_ms":14836,"temperature":1.0,"reasoning_tokens":1688,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-06T19:07:33.291068+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Map the full CO(2-1) extent of a sample of passive E/S0 galaxies more than 1.5 dex below the star-forming main sequence with total-power or interferometric observations, and compare the directly measured global CO luminosities with the APEX aperture-corrected values; agreement around the expected factor of 1.7 would confirm the central SFE suppression, while a systematic offset would show it is an artifact of the correction.","supporting_citations":[],"review_version":1}