eROSITA cosmology with galaxy groups: Hot gas budget out to the virial radius

A. Finoguenov; D. Eckert; E. Tempel; F. Gastaldello; H. Khalil; L. Lovisari; R. Seppi

REVIEW

eROSITA cosmology with galaxy groups: Hot gas budget out to the virial radius

H. Khalil, A. Finoguenov, D. Eckert, R. Seppi, E. Tempel, L. Lovisari, F. Gastaldello

Astrophysics of Galaxies · Submitted 18 Aug 2026 · Published version

Pith's verdict: First unstacked eROSITA gas fractions out to R200 for a complete group sample, with a robust sub-cosmic answer—but the headline precision misses a known ~30% gas-mass systematic.

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arXiv ID2608.17735 (version 2)

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CitationA. Finoguenov, D. Eckert, E. Tempel, F. Gastaldello, H. Khalil, L. Lovisari, R. Seppi. "eROSITA cosmology with galaxy groups: Hot gas budget out to the virial radius." arXiv:2608.17735 (2026). https://pith.science/paper/YDDJEDJ4

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Editor's note

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Khalil et al. report the first individual-system eROSITA gas mass and fraction measurements out to R200 for a complete, optically selected sample of 25 groups. That alone is worth something: the unstacked approach preserves system-to-system scatter that stacking analyses smooth over, and the sample selection is clearly described. The central result—f_gas,500 ~4.3% and f_gas,200 ~5.8% at median masses around 10^13.5 Msun—confirms that groups retain only a third to half of the cosmic baryon fraction as hot gas even at the virial radius. The comparison to FLAMINGO, BAHAMAS, and the SP(k) power-spectrum inference is a useful step, and the agreement with Popesso et al. (2026) at R200 with roughly twice the statistical precision is a nice check.

The main soft spot is the error budget. Section 3.2 states that for kT~1 keV systems, assuming a single temperature and a fixed metallicity can introduce up to ~30% systematic uncertainty in the gas mass. The quoted uncertainties on f_gas,500 and f_gas,200 (e.g., ±0.42%) come from Monte Carlo propagation of M200c, c200c, and the statistical Mgas errors only. That 30% term is not in the reported errors. Appendix E shows eROSITA gas masses are 15±4.5% lower than matched Chandra/XMM measurements—an offset of the same order as the quoted statistical errors. So the precision claims and the multi-sigma tensions with strong-feedback FLAMINGO variants are not on the same footing as the nominal errors. The qualitative sub-cosmic conclusion is robust to a 30% shift; the 10-15% power-spectrum suppression is less so, since that inference is normalization-sensitive.

The aperture covariance correction (Eqs. 8–10) uses the beta parameter fitted from the same surface brightness profiles. That's somewhat self-referential, and I'd like to see how sensitive the corrected slopes are to the beta uncertainty. It's not fatal—the central f_gas values are direct measurements—but it deserves a sensitivity test. Similarly, the steepening beyond R500 (beta rising from 0.38±0.04 to 0.76±0.19) is about a 2-sigma effect; calling it 'significant' and using it as a point of tension with strong-feedback models is a bit much. The selection function is modeled via the Seppi et al. (2025) calibration but not fully derived from the halo mass function; that's a minor limitation for an optically selected sample.

Overall: this is a carefully done paper with a new dataset and an honest statement of its main systematic—the problem is that the systematic isn't propagated into the headline numbers. It deserves a serious referee; the fix is straightforward: add the temperature/metallicity term to the error budget and soften the precision-based claims accordingly. I'd bring it to a reading group focused on galaxy groups and feedback.

Referee report

Significance

The underlying dataset and analysis constitute a useful step forward: individual-system eROSITA constraints on gas fractions out to R200 for a statistically complete group sample, with roughly double the statistical precision of recent stacking studies. The paper is careful in its process details: in-flight PSF calibration validated against the half-energy width (Appendix C), per-tile particle background maps from FWC-calibrated hard-band counts (Appendix B), background apertures selected to avoid extended emission (Appendix D), and external cross-checks of gas masses against Chandra/XMM (Appendix E). The hierarchical Bayesian treatment of the true-mass distribution and the aperture covariance is more sophisticated than in most comparable work, and the comparison covers a broad grid of feedback models. The falsifiable predictions—a 10-15% suppression of the matter power spectrum at k~5 h/Mpc and the specific ranking of FLAMINGO variants—are clearly stated.

Major objections (3)

[§3.2, §3.4, §4.2] The reported fgas values carry only the Monte Carlo propagated statistical errors from M200c, c200c, and Mgas (§3.4), yet §3.2 states that the constant-temperature and fixed-metallicity assumptions introduce an 8±2% systematic from the XXL LX-T scatter and up to ~30% for kT~1 keV systems; neither term appears in the quoted fgas,500=4.32±0.42% and fgas,200=5.78±0.69% (§4.2, abstract). Appendix E provides a direct estimate of the missing term: for the seven matched groups, eROSITA gas masses are 15±4.5% lower than Chandra/XMM at the same radius, an offset larger than the quoted statistical errors. The same omission propagates into the simulation tension significances (§4.3.3-4.3.4, 2.2-8.6σ) and the inferred 10-15% matter power spectrum suppression (§5), all of which are normalization-sensitive. I request that the systematic be propagated (e.g., as a 15% floor from Appendix E, with the 30% case bracketed), that the tension significances and the SP(k) confidence band be recomputed with it, and that the abstract's precision claims relative to stacking studies be recalibrated. The qualitative conclusion of a sub-cosmic hot gas fraction is robust to this issue, but the quoted precision is not.
[§4.1 and abstract] The claimed steepening of the stacked surface brightness profile from β=0.38±0.04 (0.15-1 R500) to β=0.76±0.19 (R500-R200) is only about 2σ significant (difference 0.38 versus combined uncertainty √(0.04²+0.19²)≈0.19), and if the inner and outer fits to the same stacked profile are covariant the true significance would be lower. Because this steepening is presented as 'a first point of tension with strong feedback models' (§4.1) and is used to interpret the Mgas-Mtot slope (§4.3.4), I ask the authors to quantify the significance properly (e.g., a joint single-β versus broken-β fit, or a bootstrap over groups) and to soften the abstract and summary wording accordingly.
[§4.3.1, Eqs. (7)-(10), Table 1, Appendix G] The aperture covariance correction rescales each group's Mgas and LX using the β parameter fitted from the same surface brightness profiles (Table F.3) via Mgas∝Mtot^(1-β) and LX∝Mtot^(1-2β). The corrected Mgas-Mtot slope (Table 1, B=1.59+0.34/-0.28) is thus partly determined by the measured β values and by the assumed beta-model scaling of Eq. (7). The paper tests one alternative (the steeper stacked outer β) but does not propagate the β uncertainties, including their covariance, into the scaling-relation posteriors of Appendix G, nor does it test departures from the isothermal beta-model form. Given that the uncorrected relation natively reproduces the HSC-XXL result (Fig. 9), the correction is doing substantial work; please propagate the β uncertainty in the hierarchical likelihood or demonstrate that the slopes, intrinsic scatter, and simulation tensions are robust to a conservative β range.

Minor objections (6)

[§2.3] The sentence 'verify their consistency with the AGN feedback simulations of Munari et al. (2013)' is inaccurate: Munari et al. (2013) calibrates the velocity dispersion-mass relation from cosmological simulations and is not an AGN feedback study; please correct the characterization of this reference.
[Appendix E] There is a likely identifier error: both 2MRS 2657 and 2MRS 2938 are labeled NGC 2832 in the text, while the Fig. E.1 caption labels 2MRS 2657 as NGC 2563; please check the galaxy identifications. Also fix the typo 'mesaure' and consider a small table listing the matched radius, energy band, instrument, and reference for each of the seven groups so the 15±4.5% offset statement can be verified entry by entry.
[Fig. 3 caption] The in-figure labels '0.15 R500c', 'R200c', 'R500c' are garbled and the two fit ranges ([0.15-1]R500 and R500-R200) should be marked unambiguously; the caption should also state the significance of the steepening given major comment 2.
[References and §2.3/§3.2] The manuscript relies on several unpublished or companion works (Finoguenov et al. 2026, submitted; Seppi et al. in prep.; Eckert et al. 2026; Popesso et al. 2026; Siegel et al. 2026a,b). Please give the arXiv identifiers or acceptance status for these, and inline the essential selection-completeness statement from Finoguenov et al. (2026) so the sample definition is self-contained.
[§4.3.4] The quoted simulation deviations (e.g., 1.74σ for SIMBA and 2.41σ for BAHAMAS at the median mass) are not accompanied by a definition of how σ is computed (posterior predictive distribution, covariance of A and B, or residual at the pivot); a one-sentence definition would make the tension claims reproducible.
[Table F.1] The column header row (Group ID, Field ID, z, σv, LX,500, LX,200, R500c, Ngal) is typeset without separators between the redshift and velocity-dispersion columns, making the table hard to read; please format the header properly.

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The paper

The paper claims

Galaxy groups keep only a third to half of their cosmic share of hot gas even at the virial radius, and the strongest feedback variants of the FLAMINGO simulation cannot reproduce the data.

The reading

This paper sets out to establish that galaxy groups, the most common dark-matter halos, hold far less hot gas than the cosmic baryon budget predicts, even at the virial radius: $f_{\mathrm{gas,500}} = 4.32\pm0.42\%$ at $M_{500} = 2.54\times10^{13}\,M_\odot$ and $f_{\mathrm{gas,200}} = 5.78\pm0.69\%$ at $M_{200} = 3.69\times10^{13}\,M_\odot$, against a cosmic gas fraction of roughly 13 percent. That matters because the gas expelled from groups is the main agent by which baryonic feedback suppresses the matter power spectrum on megaparsec scales, a leading systematic for weak-lensing cosmology. Using the same 25 groups, the paper finds that the strongest AGN feedback variants of the FLAMINGO simulation are excluded at 2.5–8$\sigma$, while fiducial FLAMINGO and BAHAMAS match the data, and infers a 10–15 percent suppression of the matter power spectrum at $k = 5\,h\,\mathrm{Mpc}^{-1}$. A sympathetic reader would take this as the first individual-system X-ray census of the group baryon budget out to $R_{200}$ with enough precision to discriminate between feedback implementations.

What carries the argument

The central object is the cumulative hot gas fraction profile $f_{\mathrm{gas}}(<r) = M_{\mathrm{gas}}(<r)/M_{\mathrm{NFW}}(<r)$, obtained by converting background-subtracted eROSITA surface brightness profiles into emission-measure profiles under a single-temperature assumption from the XXL $L_X$–$T$ relation, deprojecting them to 3D gas density via a multiscale King-function decomposition, and dividing by NFW total masses whose concentrations come from a mass–concentration relation. Two devices carry the argument: the aperture-covariance correction, which uses the $\beta$-model identity $f_{\mathrm{gas}} \propto M_{\mathrm{tot}}^{-\beta}$ to remove the artificial flattening of scaling relations whose two axes share an integration radius, and the SP(k) model, which converts the fitted baryon-fraction–mass relation into a prediction for the suppression of the matter power spectrum. The scaling relations themselves come from a Bayesian hierarchical fit whose true-mass prior is calibrated with a velocity-dispersion–mass relation.

Extended reading notes

Core claim

From eROSITA surface brightness profiles of 25 low-redshift galaxy groups ($0.01<z<0.025$) selected from the 2MRS-eRASS1 cross-match, the paper reports uniformly flat inner X-ray profiles with a mean slope parameter $\beta = 0.38\pm0.04$ inside $R_{500}$, steepening to $\beta = 0.76\pm0.19$ between $R_{500}$ and $R_{200}$. The hot gas fraction rises with radius yet stays sub-cosmic: $4.32\pm0.42\%$ at $R_{500}$ and $5.78\pm0.69\%$ at $R_{200}$, roughly a third to a half of the expected cosmic share of hot gas. The gas-mass–total-mass and luminosity–mass relations, corrected for the covariance between axes that share an integration radius, are inconsistent with the strongest FLAMINGO feedback variants at the 2.5–8$\sigma$ level, while fiducial FLAMINGO, BAHAMAS, and SIMBA match at the 1–2$\sigma$ level. Combined with stellar fractions, the measured baryon budget implies a 10–15 percent suppression of the matter power spectrum at $k = 5\,h\,\mathrm{Mpc}^{-1}$ relative to a dark-matter-only universe.

Load-bearing premise

The gas mass measurement assumes that each group's hot gas is at one constant temperature given by the XXL luminosity–temperature scaling relation, with a fixed 0.3 solar metallicity; the paper notes this can shift the inferred gas mass by up to 30 percent for the $\sim\!1$ keV systems in the sample, and the quoted $f_{\mathrm{gas}}$ uncertainties do not include that term.

Editorial extensions

If this is right

Even at the virial radius the groups hold only about 44 percent of their cosmic share of hot gas, so AGN-driven ejection must extend past $R_{200}$ for typical group-scale halos.
Strong-feedback FLAMINGO variants underpredict the X-ray luminosity at the sample median mass by 6.5$\sigma$ and 8.6$\sigma$, excluding the most energetic AGN injection schemes as descriptions of group outskirts.
The matter power spectrum is suppressed by 10–15 percent at $k = 5\,h\,\mathrm{Mpc}^{-1}$ relative to a dark-matter-only universe, consistent with fiducial FLAMINGO and BAHAMAS, a range narrow enough to matter for weak-lensing survey analyses.
The outer density profile steepening ($\beta$ rising from $0.38\pm0.04$ to $0.76\pm0.19$) means group outskirts, not just cores, carry a measurable feedback signature.
The steeper-than-self-similar $M_{\mathrm{gas}}$–$M_{\mathrm{tot}}$ slope ($B = 1.59^{+0.34}_{-0.28}$ at $R_{500}$) quantifies how gas expulsion grows toward lower masses.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

The aperture-covariance correction of this paper implies that any $f_{\mathrm{gas}}$–$M_{\mathrm{tot}}$ comparison that mixes mass proxies with shared radii is partly geometric; re-analysing published samples with the $f_{\mathrm{gas}} \propto M_{\mathrm{tot}}^{-\beta}$ correction would likely steepen their slopes and shrink the apparent scatter.
Because the quoted $f_{\mathrm{gas}}$ uncertainties exclude the up-to-30 percent single-temperature systematics, the absolute normalization of the 10–15 percent power-spectrum suppression is less secure than the relative ranking of simulation variants; per-group spectral temperatures would convert this constraint from conditional to absolute.
The $f_{\mathrm{gas,200}}/f_{\mathrm{gas,500}}$ ratio displayed per system behaves like a feedback-strength indicator, and tracking it across mass and redshift in the deeper eRASS survey could map where baryons close their account without needing absolute gas masses.
If the steepening beyond $R_{500}$ is generic across optically selected X-ray groups, then cluster stacks that assume a single $\beta$ out to the virial radius will systematically misestimate outskirts emission; this can be tested by re-stacking eRASS1 clusters with the two-slope profile.

Original abstract

Non-gravitational processes that expel hot gas beyond the virial regions of groups and clusters of galaxies, known collectively as baryonic feedback, play a key role in reshaping the matter distribution of the Universe on Mpc scales. We use eROSITA observations of a complete sample of 25 galaxy groups selected from the first public release of the eROSITA-DE data (eRASS1) and identified with the Two Micron Redshift Survey optical group catalogue (2MRS). We extract and fit surface brightness (SBx) profiles and present hot gas mass and hot gas fraction profiles out to $R_{200}$. We perform a Bayesian analysis of $M_{\mathrm{gas}}-M_{\mathrm{tot}}$, $L_{\mathrm{X}}-M_{\mathrm{tot}}$, and $L_{\mathrm{X}}-M_{\mathrm{gas}}$ relations, taking into account the aperture covariance effects. At $R_{500}$, we report uniformly flat SBx profiles with a mean $\beta$ parameter of $0.38 \pm0.04$, steepening to $\beta = 0.76\pm0.19$ beyond $R_{500}$. We measure a sub-cosmic hot gas fraction at the median mass of our sample $M_{500} = 2.54\times10^{13}M_{\odot}$ of $ f_{\mathrm{gas,500}} = 4.32\pm0.42\%$. Similarly, at $R_{200}$ and the median mass $M_{\mathrm{ 200}} = 3.69\times10^{13}M_{\odot}$, we obtain $f_{\mathrm{gas,200}}=5.78\pm0.69\%$. Our $f_{\mathrm{gas}}-M_{\mathrm{tot}}$ and $L_{\mathrm{X}}-M_{\mathrm{tot}}$ relations show significant deviations from the predictions of the strong feedback variants of the FLAMINGO simulation ($2.5\sigma$ to $8.0\sigma$ tension), while fiducial FLAMINGO and BAHAMAS provide the closest match to our measurements. Using our measured baryon fractions and the SP(k) model, we infer a $10\%-15\%$ reduction in the matter power spectrum at $k = 5\ h\ \mathrm{Mpc}^{-1}$ relative to a dark matter-only universe, in agreement with fiducial FLAMINGO and BAHAMAS, while revealing a growing tension on smaller scales with the strong feedback variants.

The compiled record

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Compiled by classifier-1.13.0 via TypeSafe API, question bank abstract-p1-20260923, 2026-09-23: 1 request, 7,821 input tokens.

What the abstract itself states, as probabilities: claims first 0.03 · states limitation 0.19 · human participants 0.01 · controlled comparison 0.39 · randomized assignment 0.01 · states quantitative result 0.99 · compares with prior results 0.93 · mentions code or data availability 0.03.

The abstract, sentence by sentence

arXiv listing abstract v2. Results and the main claim are underlined; show every role.

Non-gravitational processes that expel hot gas beyond the virial regions of groups and clusters of galaxies, known collectively as baryonic feedback, play a key role in reshaping the matter distribution of the Universe on Mpc scales. We use eROSITA observations of a complete sample of 25 galaxy groups selected from the first public release of the eROSITA-DE data (eRASS1) and identified with the Two Micron Redshift Survey optical group catalogue (2MRS). We extract and fit surface brightness (SBx) profiles and present hot gas mass and hot gas fraction profiles out to $R_{200}$. We perform a Bayesian analysis of $M_{\mathrm{gas}}-M_{\mathrm{tot}}$, $L_{\mathrm{X}}-M_{\mathrm{tot}}$, and $L_{\mathrm{X}}-M_{\mathrm{gas}}$ relations, taking into account the aperture covariance effects. At $R_{500}$, we report uniformly flat SBx profiles with a mean $\beta$ parameter of $0.38 \pm0.04$, steepening to $\beta = 0.76\pm0.19$ beyond $R_{500}$. We measure a sub-cosmic hot gas fraction at the median mass of our sample $M_{500} = 2.54\times10^{13}M_{\odot}$ of $ f_{\mathrm{gas,500}} = 4.32\pm0.42\%$. Similarly, at $R_{200}$ and the median mass $M_{\mathrm{ 200}} = 3.69\times10^{13}M_{\odot}$, we obtain $f_{\mathrm{gas,200}}=5.78\pm0.69\%$. Our $f_{\mathrm{gas}}-M_{\mathrm{tot}}$ and $L_{\mathrm{X}}-M_{\mathrm{tot}}$ relations show significant deviations from the predictions of the strong feedback variants of the FLAMINGO simulation ($2.5\sigma$ to $8.0\sigma$ tension), while fiducial FLAMINGO and BAHAMAS provide the closest match to our measurements. Using our measured baryon fractions and the SP(k) model, we infer a $10\%-15\%$ reduction in the matter power spectrum at $k = 5\ h\ \mathrm{Mpc}^{-1}$ relative to a dark matter-only universe, in agreement with fiducial FLAMINGO and BAHAMAS, while revealing a growing tension on smaller scales with the strong feedback variants.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#	sentence	role	the authors' own work	states the main conclusion	strength
s0	Non-gravitational processes that expel hot gas beyond the virial regions of groups and clusters of galaxies, known collectively as baryonic feedback, play a key role in reshaping the matter distribution of the Universe on Mpc scales.	background 1.00	0.04	0.05	asserted 1.00
s1	We use eROSITA observations of a complete sample of 25 galaxy groups selected from the first public release of the eROSITA-DE data (eRASS1) and identified with the Two Micron Redshift Survey optical group catalogue (2MRS).	method 0.97	0.96	0.02	asserted 0.96
s2	We extract and fit surface brightness (SBx) profiles and present hot gas mass and hot gas fraction profiles out to $R_{200}$.	method 0.66	0.97	0.03	asserted 0.98
s3	We perform a Bayesian analysis of $M_{\mathrm{gas}}-M_{\mathrm{tot}}$, $L_{\mathrm{X}}-M_{\mathrm{tot}}$, and $L_{\mathrm{X}}-M_{\mathrm{gas}}$ relations, taking into account the aperture covariance effects.	method 0.97	0.97	0.03	asserted 0.90
s4	At $R_{500}$, we report uniformly flat SBx profiles with a mean $\beta$ parameter of $0.38 \pm0.04$, steepening to $\beta = 0.76\pm0.19$ beyond $R_{500}$.	result 1.00	0.96	0.07	asserted 1.00
s5	We measure a sub-cosmic hot gas fraction at the median mass of our sample $M_{500} = 2.54\times10^{13}M_{\odot}$ of $ f_{\mathrm{gas,500}} = 4.32\pm0.42\%$.	result 1.00	0.98	0.08	asserted 1.00
s6	Similarly, at $R_{200}$ and the median mass $M_{\mathrm{ 200}} = 3.69\times10^{13}M_{\odot}$, we obtain $f_{\mathrm{gas,200}}=5.78\pm0.69\%$.	result 1.00	0.98	0.06	asserted 1.00
s7	Our $f_{\mathrm{gas}}-M_{\mathrm{tot}}$ and $L_{\mathrm{X}}-M_{\mathrm{tot}}$ relations show significant deviations from the predictions of the strong feedback variants of the FLAMINGO simulation ($2.5\sigma$ to $8.0\sigma$ tension), while fiducial FLAMINGO and BAHAMAS provide the closest match to our measurements.	result 0.86	0.95	0.48	asserted 1.00
s8	Using our measured baryon fractions and the SP(k) model, we infer a $10\%-15\%$ reduction in the matter power spectrum at $k = 5\ h\ \mathrm{Mpc}^{-1}$ relative to a dark matter-only universe, in agreement with fiducial FLAMINGO and BAHAMAS, while revealing a growing tension on smaller scales with the strong feedback variants.	result 0.79	0.95	0.32	asserted 0.96

What kind of paper the classifier reports this is: empirical study 1.00 · evidence from observation or experiment 0.60.

What was examined, and what was not

sources read

arXiv listing abstract v2

not examined

full text
figures and tables
references and citing sentences
relations to other papers

levels run

P abstract

not run

S sections
T body sentences
C citations
R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

Figures

**Figure 1.** Selection criteria for the sample studied in this work.

**Figure 2.** All-sky distribution of the 2MRS-eRASS1 galaxy group

**Figure 3.** Background-subtracted X-ray surface brightness profiles

**Figure 4.** Hot gas mass and hot gas fraction profiles of the 2MRS-eRASS1 groups studied in this work.

**Figure 5.** Cumulative hot gas mass fractions of the 2MRS-eRASS1

**Figure 6.** X-ray luminosity vs. total mass at R500c. Top: The blue curve shows the covariance-corrected LX − Mtot relation for the 2MRS-eRASS1 sample studied. The blue shaded region is the 1σ confidence interval of the slope and normalisation. The orange curve shows the prediction of BAHAMAS, while the other curves represent different FLAMINGO feedback model variations (Braspenning et al. 2024). Bottom: Difference in log10 LX between the explored simulations and our observed relation at the median mass. Text annotations indicate the offset significance on the σ level. The relation at R200c…

**Figure 7.** Gas mass vs. total mass relation inside R500c. The blue curve represents the best-fit relation for 2MRS-eRASS1. The blue shaded region is the 1σ confidence interval of the slope and normalisation. The orange curve indicates the result of the HSCXXL sample (Akino et al. 2022), while the teal curve shows Popesso et al. (2026)’s result from stacking eROSITA data of GAMA galaxy groups. The relation inside R200c is shown in Fig. J.1. 4.3.4. Mgas − Mtot The gas mass vs. total mass relation probes the hot gas budget in group atmospheres. In a self-similar scenario, the gas fraction…

**Figure 8.** Hot gas fraction as a function of total mass inside

**Figure 9.** Aperture covariance correction. The best-fit corrected re

**Figure 11.** Suppression of the matter power spectrum. The black shaded area indicates our constraint on the power suppression implied

Showing 10 of the paper's 11 figures. See all figures in the PDF ↗ Figures reproduced from arXiv:2608.17735 by the authors.

References

Forward citations

Cited by 2 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

Interpreting the stacked kinetic SZ signal II: the degeneracy between satellite galaxies and baryonic feedback
astro-ph.CO 2026-10 accept novelty 6.0 of 10

Satellite galaxies mimic baryonic feedback in stacked kSZ profiles, systematically biasing inferred gas fractions and feedback strength at current measurement precision.
Baryonification IV: Constraining baryonic feedback with X-ray gas fractions
astro-ph.CO 2026-09 unverdicted novelty 5.0 of 10

Fitting a baryonification model to CHEX-MATE and eFEDs X-ray data yields gas fractions of 0.029 and 0.078 at two mass scales and a 6 to 23 percent baryonic suppression of the matter power spectrum between k=1 and k=5 h/Mpc.

How the literature uses it

What this paper does with the arXiv papers it cites

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

What it cites · 17 sentences without a confident label

Uses the method or tool of 2 papers

We model the total mass using a Navarro-Frenk-White (NFW) profile [ref] with [ref] concentrations ($c_200c$): [equation] where the NFW scale radius $r_s = r_200c/c_200c$ and the characteristic density $ρ_s = M_200c/[4πr_s^3 f(c)]$ with $f(c) = ln(1+c)-c/(1+c)$.

The Structure of Cold Dark Matter Halos · Total mass · 0.91
We follow the same extended source detection method and determination of the flux extraction regions applied in, e.g., [ref] .

AXES-2MRS: A new all-sky catalogue of extended X-ray galaxy groups · eRASS1 catalogue · 1.00

Uses data or values from 1 paper

Our redshift range $0.01 < z < 0.025$ is conservatively chosen to ensure sensitivity to group outskirts within eRASS1 spatial scales and to avoid source confusion, and is further guided by the AXES-2MRS completeness limit down to $L_X > 3×10^42$ erg s$^-1$ (Figs. 2, 10 in [ref] ).

AXES-2MRS: A new all-sky catalogue of extended X-ray galaxy groups · 2MRS-eRASS1 · 0.89

Compares with 4 papers

To put our result in context, we compare it in the top panel to a compilation of pre-eROSITA literature X-ray observations, as summarised by the fitting relation introduced by [ref] , including the results on the gas fraction by [ref] .

The physics inside the scaling relations for X-ray galaxy clusters: gas clumpiness, gas mass fraction and slope of the pressure profile · $M_gas-M_tot$ · 0.98
To put our result in context, we compare it in the top panel to a compilation of pre-eROSITA literature X-ray observations, as summarised by the fitting relation introduced by [ref] , including the results on the gas fraction by [ref] .

Scaling Properties of a Complete X-ray Selected Galaxy Group Sample · $M_gas-M_tot$ · 0.98
To put our result in context, we compare it in the top panel to a compilation of pre-eROSITA literature X-ray observations, as summarised by the fitting relation introduced by [ref] , including the results on the gas fraction by [ref] .

Chandra studies of the X-ray gas properties of galaxy groups · $M_gas-M_tot$ · 0.98

Cites as background 3 papers

The connection between the baryon fraction $f_b$ in groups and clusters and the matter power spectrum (MPS) suppression on large scales ($k < 10 h Mpc^-1$) is well established [ref] .

The FLAMINGO project: Baryon effects on the matter power spectrum · Matter power spectrum suppression · 0.96
The connection between the baryon fraction $f_b$ in groups and clusters and the matter power spectrum (MPS) suppression on large scales ($k < 10 h Mpc^-1$) is well established [ref] .

1810.0862 · Matter power spectrum suppression · 0.96
In a self-similar scenario, the gas fraction reaches the cosmic value and a linear $M_gas$–$M_tot$ relation is expected, while a steeper slope signals non-gravitational processes expelling gas beyond the virial radius [ref] .

Scaling Properties of a Complete X-ray Selected Galaxy Group Sample · $M_gas-M_tot$ · 0.91

Discussion

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