{"id":"8d1cdf6e-674d-4e3d-aa64-3c5354ce21fe","arxiv_id":"1909.00405","paper_version":2,"verdict":"ACCEPT","confidence":"HIGH","novelty_score":5.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":14,"one_line_summary":"Forecasted halo-y and galaxy-y cross-correlation measurements with DESI, SO and CMB-S4 can tightly constrain group-scale halo pressure profiles and discriminate feedback models.","lead":"This paper forecasts how well future galaxy surveys (DESI-style) and CMB experiments (Simons Observatory, CMB-S4) can measure gas pressure around galaxies by cross-correlating galaxy or halo positions with Compton-y maps. Projected detections reach hundreds of sigma, with tight enough constraints on group-scale halo pressure profiles to distinguish competing feedback models.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Cluster-calibrated miscentering priors are the load-bearing assumption for low-mass halo-y forecasts; unverified extrapolation to 1e12 Msun halos could erode the claimed ability to confirm or rule out feedback models.","rationale":"I read the paper as a model-fitting forecast whose central claim is explicitly conditional: 'Assuming modest priors on these systematics, we find...' The strongest claim in the abstract is that future measurements will enable current feedback models to be confirmed or ruled out. Within the model framework, the forecast machinery is sound: the halo model integrals, covariance treatment, survey noise curves, and Markov-chain parameter estimation are standard and carefully described. The most load-bearing assumption is the miscentering extrapolation. The paper itself flags it, and the reader's weakest-assumption analysis identifies the same point. I agree with the reader that this does not invalidate the paper, because the claim is conditional and the authors are transparent; but it is the place where the low-mass constraints—the paper's main novelty—are most fragile. Other assumptions (CIB control, zero non-Gaussian covariance for halo spectra, unity completeness, 10% mass prior) are acknowledged and either less central to the low-mass claim or likely conservative. In particular, the 10% mass prior is optimistic for 1e12 Msun halos, but the paper argues miscentering matters more at low mass, so miscentering is the sharper risk. The proposed test—rerunning the low-mass bin with a group-scale miscentering prior—would settle whether the concern lands. If the constraints survive, the central claim holds; if not, the claim should be softened. I therefore leave the verdict unchanged: the paper is an acceptable, transparent forecast whose main caveat is identified and testable.","tokens_in":23602,"tokens_out":10055,"duration_ms":93074,"concrete_test":"Recompute the Section III.B halo-based forecast for the [10^12,10^13] Msun/h bin at 0.2<z<0.3, replacing the Rykoff miscentering priors (Table I) with a prior representative of group-scale catalogs (e.g., fmis = 0.5 ± 0.25 and ln cmis = -1.0 ± 0.4). If the resulting 2-sigma band on (r/r200)^3 Pe(r) over r/r200 in [0.1,1] remains narrower than the separation between the fiducial B12 profile and the shock heating / AGN8 models, the concern is resolved. Conversely, if the band overlaps alternative feedback predictions, the abstract's 'confirm or rule out' claim should be restricted to halos with calibrated centering, or the forecast should marginalize over a group-calibrated miscentering distribution measured from hydrodynamical simulations.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim—that halo-y and galaxy-y correlations will tightly constrain pressure profiles of group-scale halos and distinguish feedback models—depends on the miscentering model in §II.D.1. The paper adopts Rykoff et al. (2016) constraints (ln cmis = -1.13±0.22, fmis = 0.22±0.11), measured for optically selected clusters, and states: 'we assume that these constraints apply to all halos in our analysis. This assumption effectively extrapolates the Rykoff et al. results to low halo masses.' §III.B then notes 'For low mass halos, priors on the miscentering fraction are more important than mass calibration.' Figure 5 shows that the fmis posterior is prior-dominated in the [10^12,10^13] Msun/h bin, so the tight low-mass pressure-profile band in Figure 3 is purchased with a cluster-calibrated prior. If group-scale centering errors are larger (e.g., fmis ~ 0.5, or a non-Rayleigh distribution), the P0-beta degeneracy at low mass will widen and the band may no longer exclude shock-heating or AGN8/AGN8.5 predictions in Figures 3 and 6. The abstract's 'assuming modest priors' makes the claim conditional, but the prior in question is not tested for the mass range that is the paper's key novelty.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"This paper forecasts how well future galaxy and halo samples (DESI-like and LSST-like) cross-correlated with Simons Observatory and CMB-S4 Compton-y maps will constrain the pressure profiles of dark matter halos. The authors use the halo model with one- and two-halo terms, a generalized NFW pressure profile based on Battaglia et al. (2012) with additional low-mass freedom, Gaussian plus non-Gaussian covariance, and parameterized systematics for halo miscentering and mass bias. They report projected signal-to-noise of roughly 40, 210, and 510 sigma for halo mass bins 10^12-10^13, 10^13-10^14, and 10^14-10^15 Msun/h, forecast tight 3D pressure profile constraints, and argue that the resulting Y-M relation constraints can distinguish feedback prescriptions such as AGN8/AGN8.5 from the shock-heating model.","tokens_in":23861,"tokens_out":9051,"duration_ms":90955,"significance":"If the forecasts hold, this work makes a strong case that small-beam CMB surveys combined with DESI/LSST galaxy samples will transform tSZ cross-correlations from detections into precision measurements of group-scale baryon physics, with direct consequences for feedback modeling and for the control of baryonic systematics in weak lensing. The analysis is careful in several respects: the parameterized treatment of miscentering and mass bias, the realistic SO/CMB-S4 noise curves including atmospheric noise and ILC residuals, and the comparison against independent hydrodynamical feedback predictions. The main caveats are that the forecasts are self-consistency forecasts in which mock data are generated with the fiducial model and fit with the same model, and that several simplifying assumptions with potentially large impact are not quantified.","major_comments":[{"comment":"The low-mass pressure-profile constraints that underpin the central claim are purchased with a cluster-calibrated miscentering prior that is explicitly extrapolated to group-scale halos: the text states that the Rykoff et al. (2016) constraints 'effectively extrapolate' to low halo masses. Since §III.B notes that for low-mass halos the miscentering-fraction prior matters more than mass calibration, and Fig. 5 shows prior-dominated fmis constraints in the low-mass bins, the tightness of the blue bands in Fig. 3 and the feedback-discrimination power in Fig. 6 depend on this unvalidated assumption. I request sensitivity tests with e.g. fmis ~ 0.5 and/or a wider ln cmis prior, and that the low-mass claims be restated as conditional on the assumed group-scale miscentering distribution.","section":"§II.D.1, §III.B, Fig. 5"},{"comment":"The non-Gaussian covariance is set exactly to zero for all halo-involving spectra on the grounds that 'the one-halo term should not contribute to the trispectrum of correlations involving halos.' This is asserted rather than demonstrated, and a naive halo-model treatment of discrete halos would seem to produce a Poisson-type contribution (e.g. proportional to the integral of dn/dM times the squared y-profile for the halo-y covariance) that is not included in the Gaussian term. Because the headline signal-to-noise values and the parameter-error forecasts in Figs. 3-6 are computed with this covariance, the impact of the omitted term should be quantified, or a derivation/citation should be supplied if the term is genuinely absent.","section":"§II.C, Eq. (22)"},{"comment":"The halo-based forecasts assume unity completeness for the halo catalog. For the lowest mass bin, 10^12-10^13 Msun/h, this is optimistic relative to existing group catalogs, and the paper itself notes that Yang et al. (2007) achieved only about 85% completeness above 10^12 Msun/h. Mass-dependent incompleteness would both enlarge the errors and bias the recovered pressure profiles. A sensitivity test at plausible completeness levels, or a discussion of how incompleteness would propagate into the Fig. 3 constraints, would strengthen the forecasts.","section":"§II.E.2"}],"minor_comments":[{"comment":"'Viral mass' should read 'virial mass' in the sentence describing the relation between r_s and r_vir.","section":"§II.B"},{"comment":"The assumption that CIB contamination can be controlled below statistical errors is an important caveat for the high-redshift bin (0.9 < z < 1.2) in Fig. 3, where the authors acknowledge CIB is more problematic; a quantitative estimate of the residual CIB bias would help the reader assess the high-redshift constraints.","section":"§II.D.3, Fig. 3"},{"comment":"The reference labeled 'Planck Collaboration et al., 2016a' appears malformed (it contains '] 10.1051 /0004-6361/201629022' in place of a complete citation) and should be corrected.","section":"References"},{"comment":"The y-axis labels use the ratio \tilde Y500/(M500/10^15 h^-1 Msun)^5/3; defining \tilde Y once in the caption or text, as is done in Eq. (33), would make the figures easier to interpret without cross-referencing.","section":"Figs. 6 and 9"}],"recommendation":"major_revision","confidential_remarks":"The paper is a solid forecast with clear methodology and realistic survey assumptions. The main issues are the untested extrapolation of cluster-calibrated miscentering priors to group-scale halos and the unquantified neglect of non-Gaussian covariance for halo-involving spectra; both are addressable with sensitivity tests and should be required before publication. I recommend major revision rather than rejection."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Short version: this is one of the better forecast papers I have seen in this area. It takes a standard halo-model pipeline, makes the systematics explicit, and gives numbers that will be useful for planning DESI/SO/CMB-S4 cross-correlations. The genuinely new pieces are the piecewise low-mass pressure profile extension (Eq. 10), the combined miscentering and mass-bias treatment, and the survey-specific forecasts. It is honest about what a self-consistency forecast can and cannot say.\n\nWhat the paper does well: the model equations are standard and clearly presented, the priors are tabulated, and the covariance treatment follows the literature. The comparison against y-autospectrum-only constraints makes a strong case that halo- and galaxy-y correlations are the route to low-mass pressure profiles. The galaxy-based forecasts marginalize over HOD parameters and still show discriminating power between feedback models, which is a stronger result than I expected. Credit where it is due.\n\nSoft spots, in order. First, the forecast is self-consistency by construction: mock data generated from the fiducial model are fit with the same model, so the tight bands in Figures 3, 6, and 9 should be read as upper limits on constraining power, not predictions that the real sky will cooperate. That is standard for forecast papers, but worth saying plainly. Second, the stress-test concern about miscentering lands. The Rykoff et al. cluster constraints are extrapolated to 1e12 Msun halos, and for the lowest mass bin the fmis posterior is prior-dominated. If group-scale centering is worse than assumed, the low-mass pressure-profile bands will widen. The authors state this assumption explicitly, so I do not call it hidden; I call it the weakest load-bearing assumption in the halo-based half of the paper. Third, non-Gaussian covariance for halo-involving spectra is set to zero with no quantified impact, which could make the error bars optimistic at high ell. Fourth, the CIB and completeness assumptions are acknowledged and are probably fine at low z.\n\nThe math is standard, the citation pattern is appropriate, and no code is shipped, but the parameter tables and survey noise prescriptions are detailed enough to reproduce the essentials. Net: the paper deserves serious refereeing. The central qualitative conclusion, that upcoming surveys can turn y cross-correlations into real feedback constraints, is well supported within the model framework. I would send it out.","headline":"Solid, clearly-written forecast that makes a real subfield contribution; the low-mass halo constraints lean on a cluster-calibrated miscentering prior that the paper itself flags, but the galaxy-based path is independent and the central claim holds.","tokens_in":24453,"tokens_out":3140,"would_cite":true,"duration_ms":29689,"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":"Cross-correlating galaxies with CMB maps can rule out feedback models.","keywords":["thermal Sunyaev-Zel'dovich effect","Compton-y parameter","halo pressure profiles","baryonic feedback","galaxy-y cross-correlation","halo model","cosmology forecasts","DESI and CMB-S4"],"falsifier":"Measure the stacked tSZ profile around DESI-identified groups with measured masses near $10^{12}$–$10^{13}$ solar masses using a CMB-S4-like y map, and compare the recovered amplitude and shape of the pressure profile with the forecast 2-$\\sigma$ bands; the claim would be falsified if the actual error bars are much larger, or if the small-scale profile is suppressed far more than the assumed 22 percent miscentered fraction predicts.","tokens_in":23302,"feed_emoji":"🌌","tokens_out":7676,"duration_ms":65476,"temperature":0.7,"pith_summary":"This paper forecasts that cross-correlating future galaxy and halo catalogs with maps of the thermal Sunyaev-Zel'dovich effect will measure the gas pressure around dark matter halos precisely enough to discriminate between competing feedback models. The authors model halo-y and galaxy-y correlations in the halo model, adopting a parameterized pressure profile with free amplitude and shape, and include observational systematics such as halo miscentering and mass bias. For a DESI-like sample and CMB-S4-like Compton-y maps, the projected signal-to-noise reaches roughly 510 $\\sigma$ for the most massive halos and about 40 $\\sigma$ for halos near $10^{12}$ solar masses, and the inferred 3D pressure profiles are tight enough to confirm or rule out current feedback prescriptions. The paper argues that the y auto-spectrum alone cannot constrain low-mass halos, so the cross-correlations are the key probe.","feed_headline":"Cross-correlating galaxies with CMB maps can rule out feedback models","feed_subtitle":"DESI-style galaxies plus CMB-S4-style y maps should measure group-scale halo gas at 40–510 sigma.","key_machinery":"The load-bearing object is the parameterized halo pressure profile $P_e(x|M,z)$, written as a generalized Navarro-Frenk-White form with amplitude $P_0$, shape $\\beta$, and a set of mass-scaling indices, with additional low-mass freedom added for the galaxy-based forecasts. Fourier-transformed into multipole-space profiles and combined with the halo model's one- and two-halo terms, this profile predicts the halo-y and galaxy-y cross-spectra. The other essential pieces are the miscentering model (a Rayleigh-distributed offset convolved into the real-space profile) and a lognormal mass-bias distribution with a 10 percent prior, which capture the systematics that otherwise bias the inferred pressure profiles.","core_discovery":"On its own terms, the paper claims that upcoming measurements of the two-point cross-correlation between dark matter halos (or galaxies) and Compton-y maps will turn the tSZ effect into a precision probe of baryon physics in group-scale halos. Treating the pressure profile as a generalized NFW form with free amplitude P0 and shape beta, and marginalizing over miscentering and mass-bias systematics, the forecasts show 2-sigma uncertainty bands on the 3D pressure profiles that are narrow enough to separate the feedback models realized in current hydrodynamical simulations. The projected constraints on the integrated Y-M relation from halo-y correlations and galaxy-y correlations are far tighter than those from the y auto-spectrum at low halo mass, enabling a direct test of whether AGN and supernova feedback prescriptions capture the thermodynamic state of the gas.","pith_inferences":["A natural extension is to split the galaxy sample by color or star-formation activity at fixed halo mass; the same measurement would then test whether red galaxies show more extended or hotter gas, as feedback quenching scenarios predict.","Combining these tSZ cross-correlations with kinematic SZ measurements around the same halos could separate thermal from non-thermal pressure support, a quantity feedback models predict but current tSZ data alone cannot measure.","If the miscentering extrapolation to low-mass halos is wrong, the forecast degradation suggests that investing in better group centering (e.g., from deep imaging or weak-lensing peak positions) may be as valuable as deeper CMB maps for the low-mass science case.","The same HOD-based pipeline applied to photometric samples like LSST should work without the need for a group catalog, since the modeling marginalizes over the galaxy-halo connection."],"forward_implications":["DESI-like halo samples correlated with CMB-S4-like y maps should detect the one-halo tSZ signal at roughly 40, 210, and 510 sigma in the mass bins $10^{12}$–$10^{13}$, $10^{13}$–$10^{14}$, and $10^{14}$–$10^{15}$ solar masses per $h$, at $z$ between 0.2 and 0.3.","Pressure-profile constraints from halo-y correlations are good enough to distinguish the feedback models in current hydrodynamical simulations, including on the integrated $\\tilde{Y}$-$M$ relation.","The Compton-y auto-spectrum alone gives much weaker constraints on low-mass halos, so galaxy and halo cross-correlations are necessary to probe group-scale gas.","At high halo mass, the halo-y data can self-calibrate the miscentering parameters, while at low mass the assumed miscentering prior matters more than mass calibration.","Halo-y pressure constraints are only weakly degenerate with $\\sigma_8$, unlike the y auto-spectrum, so they remain informative even when cosmology is left free."],"supporting_citations":[{"why":"Supplies the fiducial AGN-200c pressure profile fit that the forecasts perturb with free amplitude and shape parameters.","marker":"[5]"},{"why":"Provides the no-feedback shock-heating pressure profile used as the contrasting model in Fig. 3.","marker":"[4]"},{"why":"Provides the feedback-model predictions (REF, AGN8, AGN8.5) that the forecast constraints are compared against on the $\\tilde{Y}$-$M$ relation.","marker":"[44]"},{"why":"Provides the miscentering distance and fraction constraints that the analysis assumes apply to all halos down to low mass.","marker":"[61]"},{"why":"Provides the CMB-S4-like survey noise specifications used for the projected Compton-y error bars.","marker":"[2]"},{"why":"Provides the Simons Observatory noise model used for the SO forecasts.","marker":"[3]"},{"why":"Defines the DESI galaxy and halo samples, including the Bright Galaxy Survey redshift distribution.","marker":"[21]"},{"why":"Supplies the HOD-based galaxy-y modeling approach for the galaxy-based forecasts.","marker":"[47]"}],"fun_headline_variants":["Galaxy-y cross-correlations will test feedback at high precision","Future y-maps can rule out current feedback models","DESI and CMB-S4 to map gas in group-scale halos","tSZ cross-correlations forecast to constrain halo gas","Upcoming surveys set to pin down halo pressure profiles"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing assumption is that the miscentering parameters measured for massive optically selected clusters (a typical offset scale and a 22 percent miscentered fraction) apply unchanged to halos as light as $10^{12}$ solar masses.","fun_headline_variants_meta":{"raw":{"variants":["Galaxy-y cross-correlations will test feedback at high precision","Future y-maps can rule out current feedback models","DESI and CMB-S4 to map gas in group-scale halos","tSZ cross-correlations forecast to constrain halo gas","Upcoming surveys set to pin down halo pressure profiles"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000204,"raw_usage":{"total_tokens":1401,"prompt_tokens":965,"completion_tokens":436,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":581,"completion_tokens_details":{"reasoning_tokens":353}},"tokens_in":581,"tokens_out":436,"duration_ms":4638,"temperature":1.0,"reasoning_tokens":353,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-14T05:54:15.443808+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Measure the stacked tSZ profile around DESI-identified groups with measured masses near $10^{12}$–$10^{13}$ solar masses using a CMB-S4-like y map, and compare the recovered amplitude and shape of the pressure profile with the forecast 2-$\\sigma$ bands; the claim would be falsified if the actual error bars are much larger, or if the small-scale profile is suppressed far more than the assumed 22 percent miscentered fraction predicts.","supporting_citations":[{"cited_title":"R., Pfrommer C., Sievers J","cited_arxiv_id":null,"evidence_quote":"Provides the no-feedback shock-heating pressure profile used as the contrasting model in Fig. 3."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Provides the feedback-model predictions (REF, AGN8, AGN8.5) that the forecast constraints are compared against on the $\\tilde{Y}$-$M$ relation."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Provides the miscentering distance and fraction constraints that the analysis assumes apply to all halos down to low mass."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Defines the DESI galaxy and halo samples, including the Bright Galaxy Survey redshift distribution."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Supplies the HOD-based galaxy-y modeling approach for the galaxy-based forecasts."}],"review_version":1}