Pith. sign in

REVIEW 4 major objections 4 minor 1 cited by

Linking stellar populations to HII regions across nearby galaxies. II. Infrared Reprocessed and UV Direct Radiation Pressure in HII Regions

T0 review · 4 major / 4 minor · reviewed 2026-08-09 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗

Pith's one-line read In 17,615 H II regions across 19 nearby galaxies, the reprocessed infrared radiation pressure is only 5% of the direct UV pressure in disks (10% in centers), and thermal gas pressure dominates all radiation pressure terms by a median…

desk verdict First census-scale direct measurement of IR-reprocessed radiation pressure in HII regions beyond the Local Group; the qualitative ordering is robust, but the 5% ftrap headline is a lower bound given unresolved dust substructure. read the letter →

arxiv 2502.00165 v2 pith:HR2BFP2J submitted 2025-01-31 astro-ph.GA

Debosmita Pathak , Adam Leroy , Todd Thompson , Laura Lopez , Ashley Barnes , Daniel Dale , Ian Blackstone , Simon C. O. Glover
show 22 more authors
Shyam Menon Jessica Sutter Thomas Williams Dalya Baron Francesco Belfiore Frank Bigiel Alberto Bolatto Mederic Boquien Rupali Chandar Mélanie Chevance Ryan Chown Kathryn Grasha Brent Groves Ralf Klessen Kathryn Kreckel Jing Li José Méndez-Delgado Erik W. Rosolowsky Karin Sandstrom Sumit Sarbadhicary Jiayi Sun Leonardo 'Ubeda
This is my paper · ORCID
classification astro-ph.GA
keywords radiationpressureHIIregionsstellarfeedbackinfrareddustemissionopticaldepthJWST-MIRInearbygalaxiestrappingfactor
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

Radiation pressure is one candidate mechanism for why star formation is inefficient, and this paper tries to measure, in a uniform way, how much of it is direct UV starlight pressed on dust, how much is dust-reprocessed infrared light, and how much comes from photoionization. Combining VLT-MUSE optical spectroscopy, JWST-MIRI mid-infrared imaging, and HST-resolved H$\alpha$ sizes for about 17,615 H II regions in 19 nearby galaxies, it obtains the first large-sample, extragalactic estimates of the infrared-reprocessed radiation pressure term. The central result is that in galaxy disks the reprocessed infrared pressure is on average 5% of the direct UV-optical pressure on dust, rising to 10% in galactic centers, and that all three radiation pressure terms are subdominant to the thermal pressure of ionized gas by a median factor $P_{\rm Therm}/P_{\rm Direct}^{\rm Rad}\approx18$. The paper also identifies a tight empirical predictor: $f_{\rm trap}=P_{\rm Reprocessed}^{\rm Rad}/P_{\rm Direct}^{\rm Rad}$ reaches about 1 when the 21-micron-to-H$\alpha$ luminosity ratio $L_{\rm F2100W}/L_{\rm H\alpha}^{\rm corr}$ is about 75. If the result holds, trapped-infrared radiation pressure is a minor feedback term for the H$\alpha$-bright region population and becomes important only in compact, heavily embedded, young sources.

What carries the argument

The central object is the trapping factor $f_{\rm trap}=P_{\rm Reprocessed}^{\rm Rad}/P_{\rm Direct}^{\rm Rad}$, which measures how much dust-reprocessed infrared photons boost the total radiation pressure. Each pressure term is computed from the spherical-shell relation $P_{\rm Rad}(\lambda)=[L(\lambda)/(4\pi R_{\rm circ}^2 c)](1-e^{-\tau(\lambda)})$, where $R_{\rm circ}$ is the circularized HST H$\alpha$ radius and $\tau(\lambda)$ is the dust optical depth at that wavelength. The infrared optical depths are extrapolated from the MUSE Balmer-decrement attenuation $A_{\rm H\alpha}$ through the paper's adopted extinction curve; the UV term uses a radiation-pressure-mean optical depth $\langle\tau_{\rm UV}\rangle$ derived from the 150 nm opacity with a published stellar-population model; and the four JWST-MIRI filter pressures are converted to total infrared pressure with dust SED models, giving a mid-IR-to-total-IR conversion factor of about 3.33. The machinery places all three pressure terms on a common geometry and luminosity scale so their ratios can be compared.

What would settle it

Measure resolved infrared and recombination-line optical depths directly at the ~1-10 pc scale of the HST regions, for example with JWST/NIRCam Paschen-$\alpha$ or Brackett-$\alpha$ maps and resolved 21-micron continuum, in a sample of these 17,615 regions. If the inferred IR optical depth at that scale is substantially higher than the MUSE-extrapolated value, the median $f_{\rm trap}$ would rise above 0.05 and IR trapping would no longer be subdominant; conversely, if the MUSE-extrapolated values hold, the paper's ordering $P_{\rm Therm}>P_{\rm Direct}^{\rm Rad}>P_{\rm Ion}^{\rm Rad}>P_{\rm Reprocessed}^{\rm Rad}$ is confirmed.

Watch

Extended reading notes

Core claim

The paper's core claim is that, for the H$\alpha$-bright H II region population in 19 nearby star-forming galaxies, reprocessed infrared radiation pressure is small compared with direct UV radiation pressure on dust, and both are small compared with thermal gas pressure. Concretely, the sample shows a median trapping factor $f_{\rm trap}=P_{\rm Reprocessed}^{\rm Rad}/P_{\rm Direct}^{\rm Rad}$ of about 0.05 in disks and 0.10 in galactic centers, a median ionization-to-direct ratio $P_{\rm Ion}^{\rm Rad}/P_{\rm Direct}^{\rm Rad}$ of about 0.3, and a median thermal-to-direct ratio $P_{\rm Therm}/P_{\rm Direct}^{\rm Rad}$ of about 18. The paper also establishes a tight empirical scaling between $f_{\rm trap}$ and the mid-IR-to-H$\alpha$ luminosity ratio, with $f_{\rm trap}\approx1$ when $L_{\rm F2100W}/L_{\rm H\alpha}^{\rm corr}\approx75$, making the 21-micron-to-H$\alpha$ ratio a practical predictor of where trapped-IR radiation pressure matters. These are the first direct estimates of the reprocessed IR pressure for a large extragalactic sample, achieved by merging high-resolution JWST-MIRI luminosities, MUSE attenuation and nebular lines, and HST sizes on a common scale.

Load-bearing premise

The calculation assumes that the roughly 90 pc resolution Balmer-decrement attenuation measured by MUSE, converted by one extinction curve into infrared and ultraviolet optical depths, describes the dust that actually absorbs radiation inside each much smaller HST-resolved region, and that all three pressure terms share a single spherical-shell geometry with $\Lambda=1$ and the same radius $R_{\rm circ}$.

Editorial extensions

If this is right

  • IR-trapped radiation pressure is a minor feedback term for the H$\alpha$-bright H II region population: in disks $f_{\rm trap}\approx0.05$ and in centers $f_{\rm trap}\approx0.10$.
  • Thermal gas pressure dominates, with median $P_{\rm Therm}/P_{\rm Direct}^{\rm Rad}\approx18$, so radiation pressure matters mainly in compact, heavily embedded, young regions.
  • The ratio $L_{\rm F2100W}/L_{\rm H\alpha}^{\rm corr}$ is a practical predictor of $f_{\rm trap}$: it implies $f_{\rm trap}\approx1$ when the ratio is about 75, and $f_{\rm trap}\approx0.1$ when the ratio is about 10.
  • Photoionization pressure is subdominant in metal-rich spirals ($P_{\rm Ion}^{\rm Rad}/P_{\rm Direct}^{\rm Rad}\approx0.3$) but is expected to dominate the radiation pressure budget in SMC-like dwarf galaxies, consistent with the two dwarfs in the sample showing the highest ratios.
  • The four JWST-MIRI filters capture about 30% of the total infrared radiation pressure despite only about 10% of the total infrared luminosity, validating mid-IR-only surveys as pressure tracers.

Reading between the lines

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

  • Beyond the paper: if the $f_{\rm trap}$ versus $L_{\rm F2100W}/L_{\rm H\alpha}^{\rm corr}$ relation holds for unresolved populations, a single mid-IR-to-H$\alpha$ color could identify which star-forming regions in higher-redshift galaxies are IR-trapping dominated.
  • Beyond the paper: the weak correlation between $A_{\rm H\alpha}$ and the mid-IR-to-H$\alpha$ ratio suggests that attenuation maps alone cannot localize where IR pressure matters; combining 21 micron and H$\alpha$ mapping would be a stronger predictor.
  • Beyond the paper: the SMC-like prediction could be tested by running the same MUSE+JWST+HST analysis on a larger sample of low-metallicity dwarfs; if $P_{\rm Ion}^{\rm Rad}$ dominates there, radiation-pressure models of early galaxies should emphasize photoionization over dust pressure.
  • Beyond the paper: if the geometry factor differs between terms, e.g., $\Lambda=3$ for volume-filling ionized gas versus $\Lambda=1$ for a dust shell, all pressures shift by a factor of 3 but the relative ordering likely survives; resolved radiation-hydrodynamic simulations could test this.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 4 minor

Summary. This paper presents a method to estimate three radiation pressure terms for ~17,615 HII regions in 19 nearby galaxies by combining JWST-MIRI mid-IR photometry, VLT-MUSE Balmer-decrement attenuation and H-alpha luminosities, and HST-based HII region sizes. Following Eq. (4), the authors compute the reprocessed IR pressure from IR luminosity and IR optical depth (Section 3.1), the direct UV/optical pressure from a bolometric luminosity and a radiation-pressure-mean UV optical depth (Section 3.2), and the photoionization pressure from the ionizing photon luminosity (Section 3.3). The main claims are that the reprocessed IR pressure is on average 5 percent of the direct UV pressure in disks and 10 percent in galaxy centers, that ftrap reaches unity for L_F2100W/L_Halpha_corr about 75, and that all radiation pressure terms are subdominant to the thermal gas pressure by about a factor of 18. The paper releases a machine-readable value-added catalog and includes appendices quantifying uncertainties from the mid-IR-to-total-IR conversion and from R_V variations.

Significance. If the quantitative 5 percent and 10 percent numbers hold, this is the largest direct estimate of IR-reprocessed radiation pressure outside the Local Group to date and a valuable constraint for stellar feedback models. The paper is unusually explicit about its assumptions, and it provides a reproducible catalog with detailed uncertainty appendices. The empirical ftrap versus L_F2100W/L_Halpha_corr scaling relation is also a useful practical predictor, and I do not see a circularity problem because the pressure terms are computed from independent observables before the scaling relation is fitted. The main quantitative conclusions rest on an unverified transfer of MUSE-resolution attenuation to HST-scale regions and on an assumed far-IR power-law opacity, both of which are acknowledged in Sections 5.2 and 5.3 but are not yet propagated into the uncertainty budget.

major comments (4)
  1. [Section 3.1 / Eq. (5) / Section 5.3 / Appendix A] The transfer of the MUSE Balmer-decrement attenuation A_Halpha, measured at 0.9 arcsec (20-85 pc), to the HST-scale R_circ (2-9 pc) is the most load-bearing assumption. Equation (5) computes P_Reprocessed linearly from tau_IR, and tau_IR is derived from A_Halpha via the G23 extinction curve; Equation (8) similarly uses A_Halpha to set the radiation-pressure-mean <tau_UV>. If the HST-bright core has a larger dust column than the MUSE beam-average, P_Reprocessed is underestimated proportionally, while P_Direct is only mildly affected because the (1 - exp(-<tau_UV>)) factor saturates. The paper itself shows in Figure 11 that A_Halpha predicts L_F2100W/L_Halpha_corr with Spearman rho = 0.09, and Section 4.2 explicitly calls this a degree of breakdown of the assumed model. Appendix A states that the equal-attenuation assumption 'will have to be verified.' Because the headline 5 percent and 10 percent ftrap values are direct consequences of this transfer, the paper needs a quantitative uncertainty for this step or a direct test, such as comparing MUSE and HST-resolution recombination-line attenuation in the 7,082 regions with HST data, to bound the possible factor of 2-3 shift in ftrap.
  2. [Section 3.1 / Appendix B / Section 5.3] The mid-IR-to-total-IR conversion factor f_MIRI^TIR = 3.33 is calibrated with HD23 dust SED models over U = 1-10^4, but the extinction curve beyond 30 microns is assumed to follow tau proportional to lambda^-2. Appendix B's Figure 15 indicates that the lambda > 30 micron tail contributes a substantial fraction of the total IR pressure, roughly 30-40 percent, so the far-IR slope directly rescales P_Reprocessed and ftrap. The quoted 15 percent uncertainty on f_MIRI^TIR appears to cover only the dependence on U, not the plausible range of beta. Section 5.3 identifies this as potentially important, but the uncertainty is not included in the quantitative error budget. The authors should add this systematic, or at least state an adopted range for beta and its effect on the central ftrap values.
  3. [Section 5.2 / Eq. (4)] All three radiation pressure terms are assigned a single shell geometry with Lambda = 1 and a single R_circ. Section 5.2 correctly notes that different terms may act at different radii or with different Lambda, but these alternatives are not propagated into the quantitative uncertainty estimates. Since ftrap is a ratio of pressures, a difference between the effective UV and IR radii changes ftrap as (R_IR/R_UV)^2, and a volume-filling versus shell distribution changes the absolute pressures by factors of order three. The paper should either bound these geometric variations with a simple parameter study or state explicitly that the reported 5 percent / 10 percent values are conditional on a common-shell geometry.
  4. [Section 4.2 and Table 3] The statement that ftrap is centered at 5-10 percent is presented as a point estimate rather than as a range that includes the dominant systematics. Table 3 reports 16th-84th percentiles of the measured distribution, which is useful, but the systematic uncertainties from the three items above are not folded into the quoted central values. A short propagation of these systematics, even with order-of-magnitude assumptions, would make the central claim easier to evaluate.
minor comments (4)
  1. [Section 4.2] In the paragraph after Eq. (13), 'IR protons' should read 'IR photons'.
  2. [Abstract] The abstract contains the typo 'Very Large Telecope'; it should be 'Very Large Telescope'.
  3. [Section 5.4] The text gives slightly different numbers for the f_MIRI^TIR variation, stating 'varies by only ~20 percent over U ~ 10-10^5' and '~15 percent over U ~ 10-10^4'; these should be reconciled to avoid ambiguity.
  4. [Figure 11] For the ftrap versus L_F2100W/L_Halpha_corr relation, reporting a scatter value (e.g., the rms or interquartile range in ftrap at fixed luminosity ratio) alongside the Spearman coefficient would make the 'tight relation' claim more quantitative.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: pressures are computed from independent multi-wavelength data and external models; the ftrap–luminosity-ratio relation is an empirical fit presented after the pressures are derived, not an input.

full rationale

The paper's derivation chain is self-contained: P_Reprocessed is built from JWST-MIRI filter luminosities, MUSE Balmer-decrement A_Halpha, the Gordon et al. (2023) extinction curve, and the Hensley & Draine (2023) dust SED models; P_Direct uses Lbol from extinction-corrected Halpha via STARBURST99 and the Blackstone & Thompson (2023) opacity ratio; P_Ion uses L_Halpha_corr with case B recombination; and all terms share an R_circ from HST sizes or the Barnes et al. (2025, in preparation) empirical size-luminosity calibration. None of these inputs is defined in terms of the reported pressures or the ftrap ratio. The ftrap versus L_F2100W/L_Halpha_corr scaling is a best-fit relation computed after the pressures, and the paper explicitly notes the algebraic expectation ('Algebraically, f_trap ∝ A_Halpha × L_IR/L_Halpha_corr'), so it is an empirical presentation rather than a hidden assumption. The self-cited companion papers provide size and luminosity calibrations calibrated on 7082 HST-detected regions, not on the pressure results, and Blackstone & Thompson (2023) is an externally published model, so these self-citations are not load-bearing in a circular sense. The MUSE-to-HST resolution transfer of A_Halpha is a stated uncertainty (Section 5.3) that could shift the absolute pressures, but it is a correctness/robustness concern, not a circular reduction. No equation or fitted parameter is equivalent to the headline result by construction.

Assumptions & free parameters 6 free parameters · 8 assumptions · 0 invented entities

The central claims rest on three external model layers: the conversion from Balmer-decrement extinction to IR/UV optical depths (G23 curve, R_V=3.1), the conversion from MIRI filter luminosities to total IR pressure (HD23 SED models, f_MIRI^TIR=3.33), and the conversion from Halpha luminosity to bolometric luminosity (STARBURST99, Lbol/L_Halpha=88). Each is independently motivated, but the absolute pressure values scale with these choices. The paper introduces no new physical entities.

free parameters (6)
  • f_MIRI^TIR (mid-IR to total-IR pressure conversion factor) = 3.33 (range 2.7-3.7)
    Global scaling from four MIRI filter pressures to total IR-reprocessed pressure, computed from HD23 dust models for U=1-1e4 (Appendix B, Eq. 7). Model-dependent but reported to vary <15% over the plausible range.
  • Lbol/L_Halpha_corr (bolometric correction) = 88
    Luminosity-weighted average over first 4 Myr of STARBURST99 SSP with Kroupa IMF (Section 2.3). Literature range 60-140; scales P_Direct linearly.
  • kappa_RP/kappa_150nm ratio = 0.78
    Ratio converting tau_150nm to radiation-pressure-mean UV optical depth <tau_UV>, from Blackstone and Thompson (2023) fiducial model for 0-1 Myr SSP (Section 3.2). Affects P_Direct through (1-e^{-<tau_UV>}).
  • h<nu_Ion> (mean ionizing photon energy) = 18 eV
    Adopted to convert extinction-corrected Halpha luminosity to absorbed ionizing luminosity (Eq. 10-11); scales P_Ion.
  • R_V (extinction curve parameter) = 3.1
    Assumed Milky Way value for G23 extinction curve; Appendix C shows ftrap can be 1.5-2.5x higher for R_V=4-5.
  • beta (far-IR extinction slope beyond 30 microns) = -2
    Power-law extrapolation tau proportional to lambda^beta for lambda > 30 microns following Draine (2011); affects the about 67% of IR pressure at lambda > 30 microns (Section 5.3, Appendix B).
assumptions (8)
  • domain assumption HII regions are modeled as spherical shells (Lambda=1) with a single equivalent radius R_circ for all three radiation pressure terms (Eq. 4).
    Adopted in Section 3; a volume-filling geometry would multiply pressures by 3, and different terms may have different Lambda (Section 5.2).
  • domain assumption The MUSE Balmer-decrement AHalpha at about 90 pc resolution is representative of the dust opacity of the HII region at all wavelengths and at HST scales.
    Used in Sections 3.1 and 3.2 to derive both tau_IR and <tau_UV>; the paper notes potential blending and resolution mismatch in Section 5.3.
  • domain assumption The G23 extinction curve with R_V=3.1 applies to all regions, with a beta=-2 power-law extrapolation beyond 30 microns.
    Used to convert AHalpha to IR/UV optical depths (Sections 3.1-3.2); Appendix C quantifies R_V dependence.
  • domain assumption HD23 dust SED models with a single ISRF intensity U describe the mid-IR-to-total-IR pressure conversion.
    Used to set f_MIRI^TIR (Appendix B); the paper argues the conversion is stable within 15% for U=1-1e4.
  • domain assumption STARBURST99 SSP models with a fully populated Kroupa IMF (0.1-100 M_sun) and luminosity-weighted average over the first 4 Myr describe the stellar population.
    Used to set Lbol/L_Halpha=88; the paper discusses age and stochasticity uncertainties in Section 5.4 and Table 5.
  • domain assumption The HST size-luminosity and MUSE-to-HST luminosity scaling relations (Eqs. A1-A3) apply to the 10,533 regions without HST detections.
    Used to assign sizes and HST-scale luminosities to 60% of the sample (Appendix A); scatter is <0.25 dex.
  • domain assumption The sample of BPT-classified, Halpha-bright regions is representative of the HII region population, not of embedded or self-obscured regions.
    The paper explicitly limits conclusions to this population (Section 5.1, Summary).
  • standard math Standard radiative transfer and Stromgren sphere relations (Eqs. 1-4, 14) apply.
    Background physics assumed without proof.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Linking stellar populations to HII regions across nearby galaxies. II. Infrared Reprocessed and UV Direct Radiation Pressure in HII Regions." pith.science (2026). https://pith.science/paper/HR2BFP2J

@misc{pith2026250200165,
  author       = {Pith},
  title        = {Pith review of: Linking stellar populations to HII regions across nearby galaxies. II. Infrared Reprocessed and UV Direct Radiation Pressure in HII Regions},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/HR2BFP2J}},
  note         = {Machine review of arXiv:2502.00165}
}
abstract

Radiation pressure is a key mechanism by which stellar feedback disrupts molecular clouds and drives HII region expansion. This includes direct radiation pressure exerted by UV photons on dust grains, pressure associated with photoionization, and infrared (IR) radiation pressure on grains due to dust-reprocessed IR photons. We present a new method that combines high resolution mid-IR luminosities from JWST-MIRI, optical attenuation and nebular line measurements from VLT-MUSE, and HST H$\alpha$-based region sizes to estimate the strength of radiation pressure in $\approx 18,000$ HII regions across 19 nearby star-forming galaxies. This is the most extensive and direct estimate of these terms beyond the Local Group to date. In the disks of galaxies, we find that the total reprocessed IR pressure is on average 5% of the direct UV radiation pressure. This fraction rises to 10% in galaxy centers. We expect reprocessed IR radiation pressure to dominate over UV radiation pressure in regions where $L_{\rm F2100W}/L_{\rm H\alpha}^{\rm corr} \gtrsim 75$. Radiation pressure due to H ionizations is lower than pressure on dust in our sample, but appears likely to dominate the radiation pressure budget in dwarf galaxies similar to the Small Magellanic Cloud. The contribution from all radiation pressure terms appears to be subdominant compared to thermal pressure from ionized gas, reinforcing the view that radiation pressure is most important in compact, heavily embedded, and young regions.

Figures

Figures reproduced from arXiv: 2502.00165 by the authors.

Figure 1
Figure 1. Radiation pressure in H II regions. UV and optical photons emitted from the central powering source interact with the surrounding dusty ISM. This results in PDirect Rad due to absorption and scattering off of dust grains and PIon Rad due to H ionization. IR-reprocessed photons emitted by dust grains also interact with the dusty ISM. This results in an additional PReprocessed Rad due to absorption of these IR photons… view at source ↗
Figure 2
Figure 2. The distribution of filter-integrated luminosities LFX = ΔλFXLλ,FX for our sample of H II regions. We separate the regions by environment following M. Querejeta et al. (2021) and plot distributions for galactic centers (yellow), spiral arms and bars (blue), and inter-arm regions (red) separately. The panels show results for the four JWST-MIRI filters (FX) that we use—F770W, F1000W, F1130W, and F2100W [PITH_FULL_IMA… view at source ↗
Figure 3
Figure 3. Left panel: the distribution of Hα attenuation, AHα, from VLT-MUSE (Section 2.1) in our sample of H II regions, colored by local environment as in [PITH_FULL_IMAGE:figures/full_fig_p007_3.png] view at source ↗
Figures from the paper (13 more)
Figure 4
Figure 4. Figure 4: Distribution of reprocessed radiation pressures PReprocessed,FX Rad for each individual MIRI filter FX. We separate regions by local environment as in [PITH_FULL_IMAGE:figures/full_fig_p008_4.png]
Figure 5
Figure 5. Figure 5: Distribution of total IR log Pk Reprocessed/ Rad B (top) and UV-optical log Pk Direct/ Rad B (bottom). Regions are again split by local environment—galactic centers (yellow), spiral arms and bars (blue), and inter-arm regions (red). The left panel treats each region eq…
Figure 6
Figure 6. Figure 6: The distribution of attenuation-corrected LH corr a . The alternate x-axis shows the corresponding Lbol estimated by assuming the average Lbol/LH corr a ratio as described in Section 2.3 The vertical dashed line indicates the luminosity of a 1000 Me SSP at the average …
Figure 7
Figure 7. Figure 7: shows this ratio for our sample. Only 2% of our target regions have 〈τUV〉 „ 0.27, and a median PP Ion / 0.3 Rad Direct Rad » . PIon represents an important but not dominant term in our sample. PIon Rad does dominate over PDirect Rad in regions with low dust attenuation…
Figure 8
Figure 8. Figure 8: includes the original (〈τIR〉 ? 1) pressures from L. A. Lopez et al. (2014) as faint purple triangles, and the optical depth-corrected pressures as bold purple triangles. After correcting for 〈τIR〉 (and 〈τUV〉 to a smaller extent), we see good agreement between PReproces…
Figure 9
Figure 9. Figure 9: Here we compare PReprocessed Rad (maroon), PDirect Rad (navy), PIon Rad (green), and the Strömgren PTherm (gray) for the full sample of H II regions. The hatched regions show the 16th–84th percentiles, and the solid lines show the median of each radiation pressure term…
Figure 10
Figure 10. Figure 10: Here we compare the medianPReprocessed Rad (maroon hexagons), PDirect Rad (blue diamonds), and PIon Rad (green squares; top row), and fP P/ trap Reprocessed Rad Direct Rad = (maroon hexagons) and PP Ion / Rad Direct Rad (green squares; bottom row) with the average sta…
Figure 11
Figure 11. Figure 11: Variation in ftrap as a function of LF2100W/LH corr a , which roughly captures the shape of the SED (left panel) and attenuation AHα, with corresponding log lo ‒ g bisector fits (solid black line). Individual regions are shown as gray background points, and density co…
Figure 12
Figure 12. Figure 12: Correlations between (left panel) Hα luminosity in erg s−1 , as measured by MUSE and HST, (center panel) HST size and HST Hα luminosity from A. Barnes et al. (2025, in preparation), and (right panel) the closure relation between MUSE luminosities and HST sizes. All pa…
Figure 13
Figure 13. Figure 13: Comparing two methods for re-scaling MIRI fluxes from MUSE regions to HST for the ∼7000 H II regions with full HST, MUSE, and JWST-MIRI coverage, colored by local environment. The x-axis scales MIRI fluxes directly by the same proportion that MUSE Hα fluxes are scaled…
Figure 14
Figure 14. Figure 14: shows the wavelength-distribution of pressure contribution in the optically thin limit across 5 orders of magnitude in U. For convenience, we define the variable ξλ = τλIλ as a proxy for the specific pressure contribution at each λ. ξλ is the optical depth-weighted sp…
Figure 15
Figure 15. Figure 15: Top panel: the fraction of total IR intensity (or flux)(TIR Id 1m 1000 m =ò l m m l ) captured by different approximations and linear combinations of MIRI filters at a range of U. First, we present the fraction of TIR flux captured by the λIλ approximation in the 7.7 …
Figure 16
Figure 16. Figure 16: quantifies the systemic uncertainty in our radiation pressure estimates due to variation in RV. As RV increases, the overall shape of the extinction curve gradually flattens, which results in a decrease in 〈τUV〉. This translates to a decrease in Pe Direct () 1 Rad µ- …

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 1 Pith paper

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

  1. The near infrared SED of young star clusters in the FEAST galaxies: Missing ingredients at 1-5 $\mu$m

    astro-ph.GA 2025-09 conditional novelty 6.0 of 10

    Observed 1.5-2.5 micron excess in embedded young star clusters in the FEAST galaxies that CIGALE stellar population models fail to fit, strongest for the youngest and lowest-mass clusters.

Reference graph

Works this paper leans on

6 extracted references · 6 canonical work pages · cited by 1 Pith paper

  1. [1]

    D., et al

    Abergel, A., Misselt, K., Gordon, K. D., et al. 2024, A&A, 687, A4 Agertz, O., & Kravtsov, A. V. 2016, ApJ, 824, 79 Agertz, O., Kravtsov, A. V., Leitner, S. N., & Gnedin, N. Y. 2013, ApJ, 770, 25 Ali, A. A. 2021, MNRAS, 501, 4136 Anand, G. S., Lee, J. C., Van Dyk, S. D., et al. 2021, MNRAS, 501, 3621 Anderson, L. D., Bania, T. M., Balser, D. S., et al. 20...

    work page 2024

  2. [4]

    Chevance, M., Kruijssen, J

    22 The Astrophysical Journal, 982:140 (24pp), 2025 April 1 Pathak et al. Chevance, M., Kruijssen, J. M. D., Krumholz, M. R., et al. 2022, MNRAS, 509, 272 Chevance, M., Krumholz, M. R., McLeod, A. F., et al. 2023, in ASP Conf. Ser. 534, Protostars and Planets VII, ed. S. Inutsuka et al. (San Francisco, CA: ASP ), 1 Chevance, M., Madden, S. C., Lebouteiller...

    work page 2025

  3. [16]

    Left panel: variation of the K

    The impact of variation in RV. Left panel: variation of the K. D. Gordon et al. (2023) extinction curves as a function of RV. Additionally, the center panel shows the scaling of PDirect Rad while the right panel shows PReprocessed Rad as a function of RV for values between 2.3 and 5.6, normalized to a our fiducial RV of 3.1. The variation in PDirect Rad re...

    work page 2023

  4. [2111]

    C., Kim, J.-G., & Kim, C.-G

    15608 Lancaster, L., Ostriker, E. C., Kim, J.-G., & Kim, C.-G. 2021a, ApJL, 922, L3 Lancaster, L., Ostriker, E. C., Kim, J.-G., & Kim, C.-G. 2021b, ApJ, 914, 89 Lang, P., Meidt, S. E., Rosolowsky, E., et al. 2020, ApJ, 897, 122 Larson, K. L., Lee, J. C., Thilker, D. A., et al. 2023, MNRAS, 523, 6061 Lee, J. C., Sandstrom, K. M., Leroy, A. K., et al. 2023,...

    work page 2020

  5. [2410]

    T., et al

    11821 Scheuermann, F., Kreckel, K., Barnes, A. T., et al. 2023, MNRAS, 522, 2369 Schinnerer, E., Emsellem, E., Henshaw, J. D., et al. 2023, ApJL, 944, L15 Schinnerer, E., & Leroy, A. K. 2024, ARA&A, 62, 369 Scoville, N. Z., Polletta, M., Ewald, S., et al. 2001, AJ, 122, 3017 Sharpless, S. 1959, ApJS, 4, 257 Skinner, M. A., & Ostriker, E. C. 2015, ApJ, 809...

    work page 2023

  6. [2412]

    M., Glover, S

    07862 Kannan, R., Marinacci, F., Simpson, C. M., Glover, S. C. O., & Hernquist, L. 2020, MNRAS, 491, 2088 Kapoor, A. U., Baes, M., van der Wel, A., et al. 2023, MNRAS, 526, 3871 Kessler, S., Leroy, A., Querejeta, M., et al. 2020, ApJ, 892, 23 Kim, J., Chevance, M., Kruijssen, J. M. D., et al. 2021, MNRAS, 504, 487 Kim, J., Chevance, M., Kruijssen, J. M. D...

    work page 2020

Pith tools

Reviewed August 9, 2026 · model on record in the stance chip above.