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REVIEW 3 major objections 4 minor 2 cited by

Early SPHEREx maps show ionizing radiation systematically depletes small PAHs across the Galactic plane.

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T0 review · grok-4.5

2026-07-13 19:28 UTC pith:TZS4B5GX

load-bearing objection First SPHEREx plane-wide 3.3 µm and Brα maps that cleanly show PDR shells and a real PAH–ionization anticorrelation; the abundance interpretation is the softest link, not the maps themselves. the 3 major comments →

arxiv 2603.23620 v2 pith:TZS4B5GX submitted 2026-03-24 astro-ph.GA

SPHEREx mapping of diffuse PAH and H II emission in the Galactic plane

Giulia Murgia , Ari J. Cukierman , Brandon S. Hensley , Matthew L. N. Ashby , James J. Bock , Tzu-Ching Chang , Shuang-Shuang Chen , Yun-Ting Cheng
show 24 more authors
Yi-Kuan Chiang Asantha Cooray Brendan P. Crill Olivier Dor\'e C. Darren Dowell Andreas L. Faisst Joseph L. Hora Howard Hui Miju Kang Jae Hwan Kang Phil M. Korngut Dennis Lee Jeong-Eun Lee Bomee Lee Carey M. Lisse Daniel C. Masters Gary J. Melnick Mary H. Minasyan Chi H. Nguyen Roberta Paladini Volker Tolls Robin Y. Wen Michael W. Werner Michael Zemcov
This is my paper
classification astro-ph.GA
keywords Near infrared astronomyPolycyclic aromatic hydrocarbonsInterstellar mediumDiffuse radiationH II regionsPhotodissociation regionsSPHERExBrackett-alpha
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

This paper presents the first large-scale SPHEREx maps of the 3.3-micron PAH emission feature and Brackett-alpha ionized-hydrogen emission across most of the Galactic plane. The 3.3-micron signal is bright throughout the disk and tracks thermal dust radiance measured by Planck, confirming that it is dominated by polycyclic aromatic hydrocarbons. Combining the maps reveals extended PAH shells around ionized gas, the classic signature of photodissociation regions. After normalizing the PAH intensity by dust radiance to produce an abundance map, the authors find a clear anticorrelation with Brackett-alpha: PAH abundance drops inside ionized regions. The result extends earlier cloud-scale and extragalactic findings to the whole Milky Way and argues that ionizing radiation is a dominant driver of small-PAH abundance variations on Galactic scales.

Core claim

A radiance-normalized 3.3-µm PAH abundance map constructed from early SPHEREx data shows a significant anticorrelation with Brα-traced ionized hydrogen, indicating systematic PAH depletion within ionized gas regions across the Galactic plane and demonstrating that ionizing radiation is a dominant driver of PAH abundance variations.

What carries the argument

Radiance-normalized PAH abundance map: continuum-subtracted 3.3-µm band excess divided by Planck dust radiance, isolating abundance variations of small neutral PAHs from changes in the local radiation field so they can be compared directly with Brα.

Load-bearing premise

The continuum-subtracted 3.3-micron excess, once divided by dust radiance, mainly tracks the abundance of small neutral PAHs rather than leftover continuum, radiation-field shape, or extinction differences.

What would settle it

A re-reduction that models the full 3.3-micron spectral profile (instead of simple band excess) and still finds no significant anticorrelation between the resulting abundance map and Brα intensity across the same Galactic-plane region would falsify the depletion claim.

Watch this falsifier. Get emailed when new claim-graph text bears on it.

If this is right

  • Ionizing radiation, not only large-scale metallicity gradients, must be treated as a primary local driver of small-PAH abundance across the Milky Way.
  • PAH-bright shells around H II regions are a widespread Galactic morphology, not limited to a few well-studied clouds.
  • The same SPHEREx spectral cubes can later yield full-sky PAH abundance maps once zodiacal light is filtered and dense-field astrometry improves.
  • Comparison of 3.3-µm depletion with longer-wavelength PAH bands will test whether destruction depends on grain size.
  • The 3.3-µm maps supply a large-scale template for Galactic dust-extinction studies that isolate the small-grain component.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If the anticorrelation holds after full spectral-profile modeling, similar abundance maps could be used as an independent ionization-parameter tracer in regions where optical recombination lines are heavily extinguished.
  • The same method applied to the 3.4-µm aliphatic feature would immediately test whether aliphatic bonds are depleted even faster than aromatic ones near ionizing sources.
  • Cross-matching the abundance map with anomalous-microwave-emission templates could show whether the carriers of AME track the same small-PAH population that is destroyed in H II regions.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 4 minor

Summary. This paper presents early SPHEREx all-sky spectral survey maps of diffuse Galactic 3.3-µm PAH emission and Brα (4.05 µm) ionized-hydrogen emission over most of the Galactic plane. The authors report a strong correlation between the continuum-subtracted 3.3-µm band excess and Planck thermal dust radiance, identify extended PAH shells around ionized regions interpreted as PDRs, and construct a radiance-normalized PAH abundance map that shows a significant anticorrelation with Brα. From that anticorrelation they conclude that ionizing radiation systematically depletes small neutral PAHs inside H II regions and is a dominant driver of 3.3-µm PAH abundance variations on Galactic scales. An extinction robustness check is cited (removing high-A_V sightlines changes the anticorrelation slope by only a few percent). The work is framed as preliminary and previews SPHEREx diffuse-ISM mapping capability.

Significance. If the abundance interpretation holds, this is a valuable first large-scale spectroscopic view of 3.3-µm PAH and Brα emission across the Milky Way plane, extending targeted Spitzer/WISE and extragalactic PHANGS-style results to Galactic scales with narrow spectral channels rather than broad photometry. Strengths include use of independent observables (SPHEREx band excess, Brα, Planck radiance), an explicit A_V robustness test, visual recovery of PDR shell morphology, and honest flagging of future improvements (zodiacal filtering, full 3.3-µm profile modeling, Galactic center astrometry). The maps would be a useful community resource for dust, extinction, and small-grain studies once released.

major comments (3)
  1. [§4–§6 / abundance map construction] The central claim—that the radiance-normalized 3.3-µm map isolates small-neutral-PAH abundance and that ionizing radiation is a dominant driver of its variations—rests on continuum-subtracted band excess divided by Planck dust radiance. Planck radiance traces large-grain equilibrium emission (∝ column × local ISRF intensity), while 3.3-µm is UV-pumped and size/charge-sensitive. Residual continuum placement under a broad aromatic feature, mismatch between big-grain heating and the PAH-exciting UV field (especially harder fields near H II regions), and shell geometry (PAHs in PDRs, Brα interior) can imprint an anticorrelation with Brα without a true abundance change. The manuscript itself defers full spectral-profile modeling of the 3.3-µm feature to future work (Discussion). Please quantify continuum-window sensitivity, test alternative continuum models, and either weaken “dominant driver
  2. [§4.2.2 / Conclusion] The anticorrelation is described as “significant” and plane-wide, but the provided text does not report the quantitative diagnostics needed to support that claim at the stated strength: correlation coefficient (or rank statistic), fit slope with uncertainties, number of independent sightlines/resolution elements after masking, binning scheme, and how upper limits or non-detections in Brα are treated. The extinction test (slope changes by only a few percent when high-A_V regions are removed) is useful but insufficient alone. Please add a figure or table with the binned relation, formal significance, and a null test (e.g., shuffle Brα or substitute a non-ionizing tracer) so the reader can judge whether ionizing radiation, rather than general star-formation intensity or column structure, drives the trend.
  3. [Methods / §2–§4 (missing or incomplete)] Methods and intermediate results appear incomplete or truncated in the manuscript as presented (Introduction ends mid-discussion of Brα advantages; text resumes on p. 13 mid-extinction paragraph). Load-bearing choices—local continuum windows for the 3.3-µm excess, zodiacal/diffuse-background filtering, Brα continuum subtraction and line isolation at R≈110, map resolution and masking of point sources/dense fields, and the exact definition of the abundance ratio—must be fully specified and reproducible. Without them the abundance interpretation and plane-wide depletion claim cannot be independently assessed. Restore complete Methods/Results sections with equations defining the excess and abundance maps.
minor comments (4)
  1. [Abstract, Introduction, Conclusion] Notation for ionized hydrogen is inconsistent (Hii, Hiiregions, H II). Standardize to H II throughout.
  2. [Introduction / Methods] Several in-prep and arXiv SPHEREx companion papers are cited (Hui et al. in prep.; Yang et al. in prep.; Cukierman et al. 2026). Where those works define pipelines used here, briefly restate the essential steps so this paper stands alone.
  3. [Abstract, §6] The abstract and conclusion assert PAH emission is “bright and detectable throughout the Galactic plane.” Please state the approximate latitude/longitude coverage, fraction of plane above a stated S/N, and any regions excluded (e.g., Galactic center) so “throughout” is quantifiable.
  4. [§5] Discussion lists many valuable future analyses (aliphatic 3.4-µm ratio, galactocentric gradient, AME correlation). Keep these brief so they do not overshadow the need for firmer support of the present abundance claim.

Circularity Check

0 steps flagged

No circularity: independent spectral maps and an empirical ratio, not a tautological prediction.

full rationale

This is an observational mapping paper, not a first-principles derivation. The 3.3-µm PAH band excess and Brα line are isolated from distinct SPHEREx spectral channels; Planck dust radiance is an external multiwavelength product. The PAH abundance map is defined as the continuum-subtracted 3.3-µm intensity divided by Planck radiance—a ratio of two measured fields—then compared to Brα. The reported anticorrelation is therefore an empirical correlation between independent observables, not a quantity forced by a fitted parameter or by construction of the abundance definition. Citations to SPHEREx instrument and early-mission papers (Bock, Korngut, Hui, Hora et al.) supply mission context and do not underwrite the scientific claim. No uniqueness theorem, smuggled ansatz, or renamed known result carries the central result. Possible residual continuum or radiation-field systematics affect correctness risk, not circularity. Score 0; steps empty.

Axiom & Free-Parameter Ledger

2 free parameters · 4 axioms · 0 invented entities

The central claim rests on standard ISM domain assumptions (PAH band physics, Brα as ionized-gas tracer, dust radiance as column proxy) plus the operational definition of 'PAH abundance' as continuum-subtracted 3.3-µm intensity divided by Planck radiance. No new particles or forces are invented. Free parameters are limited to continuum-window and filtering choices that are not fully specified in the available text.

free parameters (2)
  • local continuum windows for 3.3-µm band excess
    The PAH intensity is defined as excess above a local continuum; the exact wavelength windows and fitting method are not fully specified in the available text and affect the abundance map.
  • zodiacal-light / diffuse-background filtering choices
    Early maps are restricted to the plane partly because of residual zodiacal contamination; filtering parameters control which faint emission is retained.
axioms (4)
  • domain assumption The 3.3-µm feature is dominated by small, neutral PAHs and its continuum-subtracted intensity, after radiance normalization, traces their abundance.
    Stated in the introduction citing Draine & Li 2007 and Rigopoulou et al. 2024; load-bearing for interpreting the abundance map.
  • domain assumption Brackett-α at 4.05 µm is a sufficiently clean tracer of ionized hydrogen for plane-wide comparison, with residual extinction not driving the anticorrelation.
    Justified by higher resolving power and lower extinction than Paα; supported by the paper's high-A_V robustness test.
  • domain assumption Planck thermal dust radiance is a reliable proxy for the dust column (and thus for normalizing PAH intensity to abundance).
    Used to construct the abundance map and to claim the strong positive correlation validates the PAH signal.
  • domain assumption Standard PAH emission and photodissociation physics (destruction inside H II regions, excitation in PDRs).
    Background literature (Allamandola, Tielens, Weingartner & Draine, etc.) assumed throughout the interpretation of shells and depletion.

pith-pipeline@v1.1.0-grok45 · 13068 in / 2973 out tokens · 46130 ms · 2026-07-13T19:28:13.795400+00:00 · methodology

0 comments
read the original abstract

We present preliminary SPHEREx maps of diffuse Galactic emission tracing polycyclic aromatic hydrocarbons (PAHs) and ionized hydrogen gas, and we study their relationship across the Galactic plane. Since its launch in early 2025, the SPHEREx space telescope has been conducting an all-sky near-infrared spectral survey from 0.75 to 5.0 microns. We produce a large-scale map of the 3.3-micron PAH emission feature, which is bright and detectable throughout the Galactic plane, and find a strong correlation with the thermal dust radiance measured by Planck. We also trace ionized hydrogen gas by producing a map of Brackett-alpha emission at 4.05 microns. By combining the two maps, we identify extended shells of PAH emission associated with photodissociation regions surrounding ionized gas. We construct a PAH abundance map and find a significant anticorrelation between PAH abundance and ionized hydrogen, indicating systematic PAH depletion within ionized gas regions across the Galactic plane and demonstrating that ionizing radiation is a dominant driver of PAH abundance variations. These early SPHEREx results provide a large-scale view of PAHs and ionized hydrogen and preview the capability of the mission to map diffuse emission in the interstellar medium.

discussion (0)

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Forward citations

Cited by 2 Pith papers

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

  1. Using Scattered Near-Infrared Light to Map Water Ice in Prestellar Cores with SPHEREx

    astro-ph.GA 2026-07 conditional novelty 7.0

    Coreshine SPHEREx spectra map 3 µm H2O ice across four prestellar cores; the two densest show an unexplained central drop in ice absorption that standard Bonnor-Ebert scattering models cannot reproduce.

  2. The Lifecycle and Emission Properties of PAHs in Cosmological Hydrodynamic Galaxy Formation Simulations

    astro-ph.GA 2026-06 unverdicted novelty 7.0

    Cosmological zoom-in simulations find that grain-grain shattering in diffuse ISM gas drives rising PAH mass fraction with time, naturally producing the observed PAH-metallicity relation and inverse qPAH-molecular gas trends.

Reference graph

Works this paper leans on

46 extracted references · 10 canonical work pages · cited by 2 Pith papers

  1. [1]

    P., Crill, B

    Akeson, R., Dubois-Felsmann, G. P., Crill, B. P., et al. 2025, arXiv e-prints, arXiv:2511.15823, https://doi.org/10.48550/arXiv.2511.15823

    Pith/arXiv arXiv doi:10.48550/arxiv.2511.15823 2025

  2. [2]

    J., Tielens, A

    Allamandola, L. J., Tielens, A. G. G. M., & Barker, J. R. 1985, ApJL, 290, L25, https://doi.org/10.1086/184435

    doi:10.1086/184435 1985

  3. [3]

    J., Aboobaker, A

    Bock, J. J., Aboobaker, A. M., Adamo, J., et al. 2026, ApJ, 999, 139, https://doi.org/10.3847/1538-4357/ae2be2

    doi:10.3847/1538-4357/ae2be2 2026

  4. [4]

    2025, arXiv e-prints, arXiv:2508.20332, https://doi.org/10.48550/arXiv.2508.20332

    Bryan, S., Bock, J., Burk, T., et al. 2025, arXiv e-prints, arXiv:2508.20332, https://doi.org/10.48550/arXiv.2508.20332

    Pith/arXiv arXiv doi:10.48550/arxiv.2508.20332 2025

  5. [5]

    2023, ApJ, 958, 118, https://doi.org/10.3847/1538-4357/acf4a1

    Chiang, Y.-K. 2023, ApJ, 958, 118, https://doi.org/10.3847/1538-4357/acf4a1

    doi:10.3847/1538-4357/acf4a1 2023

  6. [6]

    F., Povich, M

    Churchwell, E., Watson, D. F., Povich, M. S., et al. 2007, ApJ, 670, 428, https://doi.org/10.1086/521646

    doi:10.1086/521646 2007

  7. [7]

    P., Bach, Y

    Crill, B. P., Bach, Y. P., Bryan, S. A., et al. 2025, ApJS, 281, 10, https://doi.org/10.3847/1538-4365/ae04cc

    doi:10.3847/1538-4365/ae04cc 2025

  8. [8]

    J., Chen, S.-S., Kang, J

    Cukierman, A. J., Chen, S.-S., Kang, J. H., et al. 2026, arXiv e-prints, arXiv:2603.25790, https://doi.org/10.48550/arXiv.2603.25790

    work page doi:10.48550/arxiv.2603.25790 2026

  9. [9]

    D., Andrews, J

    Decleir, M., Gordon, K. D., Andrews, J. E., et al. 2022, ApJ, 930, 15, https://doi.org/10.3847/1538-4357/ac5dbe

    doi:10.3847/1538-4357/ac5dbe 2022

  10. [10]

    T., & Li, A

    Draine, B. T., & Li, A. 2007, ApJ, 657, 810, https://doi.org/10.1086/511055

    doi:10.1086/511055 2007

  11. [11]

    V., Kreckel, K., Sandstrom, K

    Egorov, O. V., Kreckel, K., Sandstrom, K. M., et al. 2023, ApJL, 944, L16, https://doi.org/10.3847/2041-8213/acac92

    doi:10.3847/2041-8213/acac92 2023

  12. [12]

    V., Leroy, A

    Egorov, O. V., Leroy, A. K., Sandstrom, K., et al. 2025, A&A, 703, A103, https://doi.org/10.1051/0004-6361/202556427

    doi:10.1051/0004-6361/202556427 2025

  13. [13]

    Clayton, G. C. 2019, ApJ, 886, 108, https://doi.org/10.3847/1538-4357/ab4c3a

    doi:10.3847/1538-4357/ab4c3a 2019

  14. [14]

    C., Tielens, A

    Galliano, F., Madden, S. C., Tielens, A. G. G. M., Peeters, E., & Jones, A. P. 2008, ApJ, 679, 310, https://doi.org/10.1086/587051

    doi:10.1086/587051 2008

  15. [15]

    1999, PASP, 111, 1049, https://doi.org/10.1086/316416

    Garay, G., & Lizano, S. 1999, PASP, 111, 1049, https://doi.org/10.1086/316416

    doi:10.1086/316416 1999

  16. [16]

    D., Cartledge, S., & Clayton, G

    Gordon, K. D., Cartledge, S., & Clayton, G. C. 2009, ApJ, 705, 1320, https://doi.org/10.1088/0004-637X/705/2/1320

    doi:10.1088/0004-637x/705/2/1320 2009

  17. [17]

    D., Clayton, G

    Gordon, K. D., Clayton, G. C., Decleir, M., et al. 2023, ApJ, 950, 86, https://doi.org/10.3847/1538-4357/accb59

    doi:10.3847/1538-4357/accb59 2023

  18. [18]

    D., Misselt, K

    Gordon, K. D., Misselt, K. A., Bouwman, J., et al. 2021, ApJ, 916, 33, https://doi.org/10.3847/1538-4357/ac00b7 G´ orski, K. M., Hivon, E., Banday, A. J., et al. 2005, ApJ, 622, 759, https://doi.org/10.1086/427976

    doi:10.3847/1538-4357/ac00b7 2021

  19. [19]

    S., Draine, B

    Hensley, B. S., Draine, B. T., & Meisner, A. M. 2016, ApJ, 827, 45, https://doi.org/10.3847/0004-637X/827/1/45

    doi:10.3847/0004-637x/827/1/45 2016

  20. [20]

    S., Murray, C

    Hensley, B. S., Murray, C. E., & Dodici, M. 2022, ApJ, 929, 23, https://doi.org/10.3847/1538-4357/ac5cbd

    doi:10.3847/1538-4357/ac5cbd 2022

  21. [21]

    L., Noh, J

    Hora, J. L., Noh, J. K., Melnick, G. J., et al. 2026, ApJ, 1001, 165, https://doi.org/10.3847/1538-4357/ae5180

    work page doi:10.3847/1538-4357/ae5180 2026

  22. [22]

    J., Condon, S., et al

    Hui, H., Bock, J. J., Condon, S., et al. 2026, ApJS, 284, 10, https://doi.org/10.3847/1538-4365/ae522c

    work page doi:10.3847/1538-4365/ae522c 2026

  23. [23]

    L., Franz, B

    Kelsall, T., Weiland, J. L., Franz, B. A., et al. 1998, ApJ, 508, 44, https://doi.org/10.1086/306380

    doi:10.1086/306380 1998

  24. [24]

    M., Bock, J

    Korngut, P. M., Bock, J. J., Condon, S., et al. 2026, arXiv e-prints, arXiv:2603.29835, https://doi.org/10.48550/arXiv.2603.29835

    doi:10.48550/arxiv.2603.29835 2026

  25. [25]

    S., Chang, T.-C., & Dor´ e, O

    Lee, D., Hensley, B. S., Chang, T.-C., & Dor´ e, O. 2025, ApJ, 994, 61, https://doi.org/10.3847/1538-4357/ae0c12

    doi:10.3847/1538-4357/ae0c12 2025

  26. [26]

    Leger, A., & Puget, J. L. 1984, A&A, 137, L5 Mois´ es, A. P., Damineli, A., Figuerˆ edo, E., et al. 2011, MNRAS, 411, 705, https://doi.org/10.1111/j.1365-2966.2010.17713.x

    doi:10.1111/j.1365-2966.2010.17713.x 1984

  27. [27]

    I., Onaka, T., Sakon, I., et al

    Mori, T. I., Onaka, T., Sakon, I., et al. 2014, ApJ, 784, 53, https://doi.org/10.1088/0004-637X/784/1/53

    doi:10.1088/0004-637x/784/1/53 2014

  28. [28]

    2011, ApJ, 735, 6, https://doi.org/10.1088/0004-637X/735/1/6 Par´ e, D

    Paradis, D., Paladini, R., Noriega-Crespo, A., et al. 2011, ApJ, 735, 6, https://doi.org/10.1088/0004-637X/735/1/6 Par´ e, D. M., Chuss, D. T., Sponseller, D., Hensley, B., &

    work page doi:10.1088/0004-637x/735/1/6 2011

  29. [29]

    2026, ApJ, 998, 337, https://doi.org/10.3847/1538-4357/ae3f22

    Kogut, A. 2026, ApJ, 998, 337, https://doi.org/10.3847/1538-4357/ae3f22

    work page doi:10.3847/1538-4357/ae3f22 2026

  30. [30]

    H., et al

    Pereira-Santaella, M., Alonso-Herrero, A., Rieke, G. H., et al. 2010, ApJS, 188, 447, https://doi.org/10.1088/0067-0049/188/2/447 Planck Collaboration XX. 2011, A&A, 536, A20, https://doi.org/10.1051/0004-6361/201116470 Planck Collaboration Int. XLVIII. 2016, A&A, 596, A109, https://doi.org/10.1051/0004-6361/201629022

    doi:10.1088/0067-0049/188/2/447 2010

  31. [31]

    M., & Hensley, B

    Richie, H. M., & Hensley, B. S. 2025, arXiv e-prints, arXiv:2510.16861, https://doi.org/10.48550/arXiv.2510.16861

    doi:10.48550/arxiv.2510.16861 2025

  32. [32]

    R., Garc´ ıa-Bernete, I., et al

    Rigopoulou, D., Donnan, F. R., Garc´ ıa-Bernete, I., et al. 2024, MNRAS, 532, 1598, https://doi.org/10.1093/mnras/stae1535

    doi:10.1093/mnras/stae1535 2024

  33. [33]

    M., Bolatto, A

    Sandstrom, K. M., Bolatto, A. D., Draine, B. T., Bot, C., & Stanimirovi´ c, S. 2010, ApJ, 715, 701, https://doi.org/10.1088/0004-637X/715/2/701

    doi:10.1088/0004-637x/715/2/701 2010

  34. [34]

    J., Finkbeiner, D

    Schlegel, D. J., Finkbeiner, D. P., & Davis, M. 1998, ApJ, 500, 525, https://doi.org/10.1086/305772

    doi:10.1086/305772 1998

  35. [35]

    C., Bregman, J

    Sloan, G. C., Bregman, J. D., Geballe, T. R., Allamandola, L. J., & Woodward, E. 1997, ApJ, 474, 735, https://doi.org/10.1086/303484

    doi:10.1086/303484 1997

  36. [36]

    Smith, J. D. T., Draine, B. T., Dale, D. A., et al. 2007, ApJ, 656, 770, https://doi.org/10.1086/510549 15 SPHEREx Team. 2025, IPAC, https://doi.org/10.26131/IRSA652

    doi:10.1086/510549 2007

  37. [37]

    Tielens, A. G. G. M. 2008, ARA&A, 46, 289, https://doi.org/10.1146/annurev.astro.46.060407.145211

    doi:10.1146/annurev.astro.46.060407.145211 2008

  38. [38]

    B., et al

    Watson, C., Corn, T., Churchwell, E. B., et al. 2009, ApJ, 694, 546, https://doi.org/10.1088/0004-637X/694/1/546

    work page doi:10.1088/0004-637x/694/1/546 2009

  39. [39]

    2010, ApJ, 716, 1478, https://doi.org/10.1088/0004-637X/716/2/1478

    Watson, C., Hanspal, U., & Mengistu, A. 2010, ApJ, 716, 1478, https://doi.org/10.1088/0004-637X/716/2/1478

    work page doi:10.1088/0004-637x/716/2/1478 2010

  40. [40]

    C., & Draine, B

    Weingartner, J. C., & Draine, B. T. 2001, ApJS, 134, 263, https://doi.org/10.1086/320852

    doi:10.1086/320852 2001

  41. [41]

    W., Roellig, T

    Werner, M. W., Roellig, T. L., Low, F. J., et al. 2004, ApJS, 154, 1, https://doi.org/10.1086/422992

    doi:10.1086/422992 2004

  42. [42]

    M., Smith, J.-D

    Whitcomb, C. M., Smith, J.-D. T., Sandstrom, K., et al. 2024, ApJ, 974, 20, https://doi.org/10.3847/1538-4357/ad66c8

    doi:10.3847/1538-4357/ad66c8 2024

  43. [43]

    J., Bourke, T

    Winston, E., Wolk, S. J., Bourke, T. L., et al. 2012, ApJ, 744, 126, https://doi.org/10.1088/0004-637X/744/2/126

    work page doi:10.1088/0004-637x/744/2/126 2012

  44. [44]

    L., Eisenhardt, P

    Wright, E. L., Eisenhardt, P. R. M., Mainzer, A. K., et al. 2010, AJ, 140, 1868, https://doi.org/10.1088/0004-6256/140/6/1868

    doi:10.1088/0004-6256/140/6/1868 2010

  45. [45]

    J., Li, A., Glaser, R., & Zhong, J

    Yang, X. J., Li, A., Glaser, R., & Zhong, J. X. 2016, ApJ, 825, 22, https://doi.org/10.3847/0004-637X/825/1/22

    work page doi:10.3847/0004-637x/825/1/22 2016

  46. [46]

    2016, ApJ, 833, 272, https://doi.org/10.3847/1538-4357/833/2/272

    Yano, K., Nakagawa, T., Isobe, N., & Shirahata, M. 2016, ApJ, 833, 272, https://doi.org/10.3847/1538-4357/833/2/272

    work page doi:10.3847/1538-4357/833/2/272 2016