Pith. sign in

REVIEW 3 major objections 6 minor 1 cited by

The JWST-NIRCam View of Sagittarius C. II. Evidence for Magnetically Dominated HII Regions in the CMZ

T0 review · 3 major / 6 minor · reviewed 2026-08-11 · deepseek-v4-flash

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

Pith's one-line read JWST images show the Sgr C HII region is a web of magnetically confined filaments.

desk verdict New JWST data and careful analysis make a plausible case for magnetically confined filaments in Sgr C, but the beta<1 claim rests on an assumed 1 mG field and needs a sensitivity analysis before it can carry the abstract. read the letter →

arxiv 2412.10983 v1 pith:USM5XCZY submitted 2024-12-14 astro-ph.GA

John Bally , Samuel Crowe , Rubén Fedriani , Adam Ginsburg , Rainer Schödel , Morten Andersen , Jonathan C. Tan , Zhi-Yun Li
show 6 more authors
Francisco Nogueras-Lara Yu Cheng Chi-Yan Law Q. Daniel Wang Yichen Zhang Suinan Zhang
This is my paper · ORCID
classification astro-ph.GA
keywords SagittariusCHIIregionsCentralMolecularZoneplasmabetamagneticfieldsJWSTNIRCamBrackett-alphaemissionnon-thermalradio
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

The paper uses new JWST infrared images of the Sagittarius C HII region near the Galactic center to show that its ionized gas is organized into long, narrow filaments, unlike the smooth plasma of HII regions in the solar neighborhood. From the intensity of the Brackett-alpha recombination line and radio continuum measurements, the authors derive electron densities, thermal pressures, and — assuming a 1 milligauss magnetic field — plasma beta values below one in every measured region, from the whole nebula down to its brightest strands. They argue that magnetic pressure therefore controls the flow of plasma in Sgr C, confining it to ropes or sheets and producing the non-thermal radio component detected at 1–2 GHz. If this is right, mature HII regions in the Galactic center's Central Molecular Zone, and by extension in other galactic nuclei, evolve in a magnetically dominated regime rather than the thermally driven regime familiar from disk HII regions.

What carries the argument

The load-bearing object is the plasma $\beta$, $\beta = P_T/P_B = 2n_e kT / (B^2/8\pi)$, the ratio of thermal to magnetic pressure, computed for each filament from Brackett-$\alpha$ surface brightness. The measurement chain converts continuum-subtracted F405N images into emission measure via Case B recombination ratios, then to electron density by assuming the line-of-sight depth equals the projected width, then to thermal pressure at $T = 6{,}000$ K, and finally to $\beta$ by dividing by the magnetic pressure of an assumed $B = 1$ mG field. A second mechanism is the spectral-index comparison between 97 GHz ALMA and 1.28 GHz MeerKAT data, which separates the optically thin free-free emission of the filaments from the non-thermal component seen in the negative 1–2 GHz in-band index. The paper also adds a simple model of magnetically dominated HII region evolution in which plasma flows along field lines, ionization fronts are modified by field pressure, and photo-ablation of magnetized filaments produces field-aligned strands.

What would settle it

Measure the magnetic field strength in the Sgr C filaments directly, for example by detecting Zeeman splitting in a radio recombination line or Faraday rotation toward polarized background sources behind the filaments; if the field in the dense strands is about 0.3 mG or less rather than 1 mG, the derived plasma beta in the brightest filaments exceeds one and the central claim of magnetic dominance collapses.

Watch

Extended reading notes

Core claim

On the authors' own terms, the discovery is that the Sgr C HII region is filamentary in ionized gas and magnetically dominated. The NIRCam Brackett-alpha image shows a fractured arc of ionization fronts at about 1.85 pc from the star-forming clump, a bright 'π-shaped' set of filaments, and networks of fainter filaments pointing away from the molecular cloud, with widths from about 1,000 to 16,000 au and lengths of 0.4–4 pc. Because the 97 GHz-to-1.28 GHz spectral indices of the bright filaments are close to the free-free value while the in-band 1–2 GHz MeerKAT spectral index is negative, the region contains both optically thin thermal plasma and a non-thermal synchrotron component. Using emission measures from Brackett-alpha and an assumed 1 mG field, the authors derive plasma beta between about 0.007 (whole HII region) and 0.6 (brightest filaments) and conclude that magnetic pressure exceeds thermal pressure even in the densest strands, so the plasma is confined to magnetized ropes or sheets and all mature HII regions in the CMZ may live in this low-beta regime.

Load-bearing premise

The paper's beta values assume the magnetic field is exactly 1 mG everywhere, and the field in the ionized filaments is not measured; since beta scales as one over the field squared, a field near 0.3 mG in the dense strands would push beta above one and remove the quantitative support for magnetic dominance.

Editorial extensions

If this is right

  • If the plasma beta is below one throughout Sgr C, then the filamentary morphology seen in Brackett-alpha and radio continuum becomes a general diagnostic for magnetically dominated HII regions, and the similar filamentation already visible in MeerKAT images of Sgr B1 implies the same regime there.
  • Non-thermal synchrotron emission is an expected companion of CMZ HII regions, so 1.28 GHz radio fluxes cannot be treated as pure free-free; electron densities and Lyman-continuum luminosities derived that way will come out overestimated, as the authors show for the Sgr C nebula as a whole.
  • HII region evolution in the CMZ departs from the standard thermally driven picture: expansion proceeds preferentially along magnetic field lines, and in dense filaments the D-type ionization front can become a continuous C-type structure as magnetic pressure resists compression.
  • In these low-beta regions, Wolf-Rayet wind bubbles are channeled into cylinders rather than spheres whenever the field exceeds about 0.3 mG at the bubble radius, which the authors argue is the case for the filaments around WCL 3734.
  • If the speculation holds, radio and recombination-line observations of HII regions in external galactic nuclei may need to account for magnetic pressure, not just thermal pressure, when interpreting their morphologies and spectra.

Reading between the lines

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

  • A direct test would be to map the magnetic field in the Sgr C filaments themselves, for example with Zeeman observations of a radio recombination line or Faraday rotation measures toward background polarized sources; the paper's beta values rest entirely on the unmeasured 1 mG assumption.
  • The paper's model suggests a spatial correlation between the Brackett-alpha filaments and the negative 1–2 GHz spectral-index regions; if instead the non-thermal emission is offset from the thermal filaments, then the synchrotron component may be a foreground or background Galactic center population rather than plasma confined in the same ropes.
  • If beta remains below one in CMZ HII regions, the magnetic field can channel mass and energy released by ionizing stars back into the surrounding molecular gas, which may help explain the low star-formation efficiency of the CMZ; this connection is not made in the paper.
  • A promising extension is to apply the same filament-skeleton and orientation analysis used here to Brackett-alpha or Paschen-alpha images of other CMZ HII regions such as Sgr B1, to check whether the poloidal alignment seen in Sgr C is a general feature of this regime.
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

3 major / 6 minor

Summary. This paper presents JWST-NIRCam F405N Brackett-α imaging of Sgr C, a luminous H II region in the Central Molecular Zone, together with ALMA 97 GHz and MeerKAT 1.28 GHz continuum data. The authors find that the Brα emission is dominated by parsec-scale filaments, including a π-shaped structure and concentric arcs interpreted as ionization fronts. From Brα surface brightness they derive emission measures, electron densities, thermal pressures, and plasma beta for individual filaments and for the whole region. Using 1.28–97 GHz spectral indices and the MeerKAT 1–2 GHz spectral index map, they argue that the filaments are mostly optically thin free-free but that a non-thermal component is also present. Assuming a 1 mG magnetic field in every region, they obtain beta < 1 everywhere and conclude that Sgr C is magnetically dominated, speculating that mature CMZ H II regions generally evolve in a low-beta regime.

Significance. The observational material is strong: the JWST images resolve filament widths down to about 0.1–0.3 arcsec, and the fil_finder/RHT orientation analysis provides a quantitative statement about alignment with the poloidal field. The paper is careful with extinction, background subtraction, and resolution mismatches, and it quotes 20–30% uncertainties on the Brα-derived quantities. If the magnetic-dominance conclusion holds, it would be an important step toward revising the standard picture of H II region evolution in galactic nuclei. However, the central quantitative claim currently rests on an assumed field strength rather than a measurement, so the significance is conditional on additional support.

major comments (3)
  1. [§3.3, Eqs. (4)–(5), Table 2] The plasma beta values in Table 2 are computed with B = 1 mG assumed “in every region” (Section 3.3), but the magnetic field in the ionized filaments is not measured. Since beta ∝ B^-2, the result is highly sensitive to this assumption: for the densest entry (region 5, A_Ks = 3, P_T = 2.49e-8 dyn cm^-2), beta = 1 at B ≈ 0.79 mG, and most filament entries with beta = 0.2–0.6 reach beta = 1 at B ≈ 0.35–0.8 mG. The Introduction itself quotes CMZ field strengths of 0.1–10 mG, so B = 0.3 mG in the filaments is observationally plausible. The abstract’s claim of “plasma beta below 1, even in the densest regions” is therefore an assumption-converted quantity. Please provide a sensitivity analysis over the allowed field range or a direct field constraint toward the ionized filaments, and rephrase the conclusions accordingly.
  2. [§3.5, Table 4] The classification of the filaments as optically thin free-free depends on which background region is subtracted. Table 4 shows that using Back2 (inside the H II region) gives α2 ≈ -0.06 to +0.31, consistent with free-free, while using Back1 or Back3 gives negative indices as low as -0.25 to -0.33 for Leg 1. The text asserts that Back2 is the better estimate, but it does not justify why the non-thermal component should be absent from this local background or why the extended non-thermal emission outside should be subtracted rather than the local one. As written, the same data support both “thermal filaments” and “non-thermal filaments” depending on the choice. A resolved spectral-index map or a quantitative thermal/non-thermal decomposition is needed to support the free-free interpretation.
  3. [§3.1 and §3.5] The claim of a non-thermal component “across the entire Sgr C H II region” is based on the integrated MeerKAT in-band spectral index of -0.48, or -0.38 to -0.41 after excluding the adjacent NTF, measured over a large oval. This integrated measurement does not establish that the non-thermal emission is co-spatial with the Brα filaments; it could be foreground or background synchrotron along the same line of sight. Since the non-thermal component is used as supporting evidence for magnetic confinement, the paper should either present a resolved spectral-index map of the region or state explicitly that the non-thermal emission is merely spatially coincident rather than necessarily associated with the filaments.
minor comments (6)
  1. [§3.4, Table 5 vs Table 2] The whole-region corrected surface brightness and emission measure are inconsistent between the two tables: Table 2 lists SB = 1.95e-14 erg s^-1 cm^-2 arcsec^-2 for A_Ks = 3, which gives EM = 2.39e5 cm^-6 pc via the stated conversion, while Table 5 lists SB = 2.49e-14 and EM = 3.06e5; the raw counts also differ (25.1 versus 29.27 MJy/sr). Please reconcile.
  2. [Figure 3 caption] “Integtrated” should be “integrated” in the HNCO contour description.
  3. [§5, Conclusions] The sentence “less than the estimated 20% to 20% error” should read “20% to 30%.”
  4. [Table 1] The dimension for region 8, “0.527 × 0753,” appears to be missing a decimal point; it should likely be 0.527 × 0.753 arcsec.
  5. [§3.2, Figure 6 caption] The caption states that the orientation histogram is weighted by intensity times length, while the text says intensity times width; please make these consistent.
  6. [§3.2] For the projected Rayleigh statistic, please report a significance level or p-value rather than only Z_x = 5.8 ± 0.9, so the reader can assess the claimed alignment.

Circularity Check

0 steps flagged · score 0.0 of 10

No circular derivation: the beta<1 result is an explicitly parameterized inference from an external B=1 mG assumption, not a fitted or self-referential input.

full rationale

The paper's central quantitative claim, plasma beta below unity even in the densest filaments, is computed in Section 3.3 from measured Brackett-alpha surface brightnesses converted to emission measures and electron densities using standard Case B recombination, with thermal pressure from Eq. (3) and magnetic pressure from Eq. (5). The magnetic field strength is not measured in this paper but is explicitly assumed: 'we assume that the magnetic field has a strength of 1 mG in every region, the typical large-scale average field strength in dense CMZ clouds (Ferriere 2009; Pillai et al. 2015).' This is an openly stated external parameter, not a quantity fitted to the same Br-alpha data, and it is not defined in terms of the beta values that Table 2 reports. The beta<1 outcome is the arithmetic consequence of combining that assumed field with the independently estimated thermal pressures, so it is not a prediction equivalent to its input by construction. The non-thermal radio component is inferred from the independent MeerKAT in-band spectral index map, and the 1.28 GHz versus 97 GHz free-free decomposition is explicitly tested against three background choices in Section 3.5 and Table 4. No equation in the paper reduces to a fitted input, and no 'uniqueness theorem' is imported from the authors' prior work. The only overlapping-author citations are Paper I for JWST data reduction details and Pillai et al. (2015) for CMZ field strengths; the latter is an external, published measurement and is not used as an unverified self-referential premise. The sensitivity of beta to the assumed field strength (e.g., B near 0.3-0.8 mG would raise the densest filaments above beta=1) is a scientific robustness concern, not circularity, because the assumption is disclosed and the derivation does not conceal an input as an output. Therefore no specific circular step meets the evidence bar required by the review rules.

Assumptions & free parameters 2 free parameters · 6 assumptions · 0 invented entities

Everything quantitative in Table 2 rests on standard nebular diagnostics plus one critical input: the assumed 1 mG field strength. The paper does not fit parameters to produce its conclusions; it adopts inputs from the literature. The morphology argument is independent of the beta calculation. No new entities are introduced. The main fragility is that the field strength in the ionized filaments is assumed, not measured.

free parameters (2)
  • Assumed magnetic field strength B = 1 mG
    Used in Eq. 5 and Table 2 for every region to convert thermal pressure into plasma beta. The conclusion beta below 1 depends on this value; if B is a few times smaller in the dense filament plasma, beta exceeds 1.
  • Line-of-sight depth L for each feature = Projected minor-axis width
    Electron density from EM = n_e^2 L. For sheets seen edge-on, this overestimates n_e and thermal pressure, making the derived beta values upper limits. The paper notes this in Section 3.3.
assumptions (6)
  • standard math Case B recombination line ratios for H-alpha and Br-alpha at 5000 to 10000 K interpolated to 6000 K
    Converts Br-alpha surface brightness to emission measure; standard nebular physics from Draine 2011.
  • standard math Free-free radio continuum formulas (Mezger & Henderson 1967; Condon & Ransom 2016)
    Used to derive emission measures and densities from 1.28 GHz flux.
  • domain assumption Sgr C is at the same distance as Sgr A*, 8.15 kpc
    All linear sizes, densities, and masses scale with distance; adopted from Reid et al. 2019.
  • domain assumption An average magnetic field strength of 1 mG is representative of dense CMZ clouds
    Cited to Ferriere 2009 and Pillai et al. 2015; not measured here and not necessarily the field inside the ionized filaments.
  • domain assumption Foreground extinction A_Ks = 2 to 3 mag and A_lambda proportional to 1/lambda
    From Nogueras-Lara 2024 and Fitzpatrick 1999; extinction corrections alter Br-alpha surface brightness by factors of 2.65 to 4.31.
  • domain assumption The line-of-sight depth of a feature equals its projected width
    Needed to estimate electron densities; the paper notes this overestimates densities for edge-on sheets.

how reviews work

0 comments
Cite this review

Pith. "Pith review of The JWST-NIRCam View of Sagittarius C. II. Evidence for Magnetically Dominated HII Regions in the CMZ." pith.science (2026). https://pith.science/paper/USM5XCZY

@misc{pith2026241210983,
  author       = {Pith},
  title        = {Pith review of: The JWST-NIRCam View of Sagittarius C. II. Evidence for Magnetically Dominated HII Regions in the CMZ},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/USM5XCZY}},
  note         = {Machine review of arXiv:2412.10983}
}
abstract

We present JWST-NIRCam narrow-band, 4.05 $\mu$m Brackett-$\alpha$ images of the Sgr C HII region, located in the Central Molecular Zone (CMZ) of the Galaxy. Unlike any HII region in the Solar vicinity, the Sgr C plasma is dominated by filamentary structure in both Brackett-$\alpha$ and the radio continuum. Some bright filaments, which form a fractured arc with a radius of about 1.85 pc centered on the Sgr C star-forming molecular clump, likely trace ionization fronts. The brightest filaments form a `$\pi$-shaped' structure in the center of the HII region. Fainter filaments radiate away from the surface of the Sgr C molecular cloud. The filaments are emitting optically thin free-free emission, as revealed by spectral index measurements from 1.28 GHz (MeerKAT) to 97 GHz (ALMA). But, the negative in-band 1 to 2 GHz spectral index in the MeerKAT data alone reveals the presence of a non-thermal component across the entire Sgr C HII region. We argue that the plasma flow in Sgr C is controlled by magnetic fields, which confine the plasma to rope-like filaments or sheets. This results in the measured non-thermal component of low-frequency radio emission plasma, as well as a plasma $\beta$ (thermal pressure divided by magnetic pressure) below 1, even in the densest regions. We speculate that all mature HII regions in the CMZ, and galactic nuclei in general, evolve in a magnetically dominated, low plasma $\beta$ regime.

Figures

Figures reproduced from arXiv: 2412.10983 by the authors.

Figure 1
Figure 1. The JWST field (cyan rectangle) shown on a MeerKAT radio continuum image centered at 1.28 GHz (Heywood et al. 2022). While most NTFs, such as the Sgr C NTF, run orthogonal to Galactic plane, the NTF located to the lower-right of Sgr C is nearly parallel to the Galactic plane, as mentioned in the text. morphology is not unique to Sgr C; it is found in all mature CMZ Hii regions, most notably Sgr B1. None of the foreg… view at source ↗
Figure 2
Figure 2. (Top): Closeup of the MeerKAT radio continuum image at 1.28 GHz (Heywood et al. 2022) showing the environment of the Sgr C Hii region. The cyan boxes labeled Back1 and Back3 are used for background subtraction in the 97 GHz to 1.28 GHz spectral index measurements (§4). Back2 is a smaller box near the core of the Hii region and is shown in Figures 4 and 5. (Bottom): MeerKAT spectral index around 1.28 GHz [PITH_FULL_… view at source ↗
Figure 3
Figure 3. (Top): Br α emission in the JWST field. Note the bright ‘π-shaped’ filaments around [359.434, -0.086]. Blue emission and green contours show the intensity of integrated 89.9 GHz transition of HNCO in Jy/beam. The HNCO map in integtrated over a radial veloctiy range of 41.6 km s−1 centered at VLSR = -60 km s−1 . Contour levels range from 2 to 10 Jy/beam in steps of 2 Jy/beam. The beam FWHM is 1.94′′× 2.56′′ . (Middle… view at source ↗
Figures from the paper (4 more)
Figure 4
Figure 4. Figure 4: (Top): The JWST Br α image, showing the entire field, optimized to show the fainter filaments away from the Hii region core. (Bottom): The Br α image showing some of the various types of filaments discussed in the text, color-coded according to the legend shown in the …
Figure 5
Figure 5. Figure 5: A closeup view of the Br-α emission from the π-shaped filaments and the cylindrical cavity centered on the Wolf￾Rayet star WCL 3734. Following instructions in the fil finder tutorial1 , a mask was first constructed on the brightest portion of the Sgr C Hii region with …
Figure 6
Figure 6. Figure 6: Top: NIRCam Brα image of the brightest portion of the Sgr C Hii region (see [PITH_FULL_IMAGE:figures/full_fig_p011_6.png]
Figure 7
Figure 7. Figure 7: A finder chart showing the locations of the next six figures, labeled from A1 to A6. APPENDIX A. GALLERY OF MAGNIFIED VIEWS OF THE SGR C Hii REGION We present close-up views of selected regions in the Sgr C Hii region [PITH_FULL_IMAGE:figures/full_fig_p025_7.png]

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 Nearest Galactic Nucleus: Studying the Galactic Centre with SKA-Mid

    astro-ph.GA 2026-06 unverdicted novelty 4.0 of 10

    A multi-wavelength SKA1-Mid continuum survey of ~290 pc × 60 pc around Sgr A* plus decade-long NSC monitoring can address remnant, pulsar, massive-star, star-formation and magnetic-field science with one dataset.

Reference graph

Works this paper leans on

85 extracted references · 17 canonical work pages · cited by 1 Pith paper

  1. [2]

    A., Wilson, R

    Bally, J., Stark, A. A., Wilson, R. W., & Henkel, C. 1987, ApJS, 65, 13, doi: 10.1086/191217 —. 1988, ApJ, 324, 223, doi: 10.1086/165891 Magnetic HII Regions 23

    doi:10.1086/191217 1987

  2. [3]

    S., Rood, R

    Balser, D. S., Rood, R. T., Bania, T. M., & Anderson, L. D. 2011, ApJ, 738, 27, doi: 10.1088/0004-637X/738/1/27

    doi:10.1088/0004-637x/738/1/27 2011

  3. [4]

    2024, ApJ, 961, 176, doi: 10.3847/1538-4357/ad0daa

    Biswas, S., Mondal, S., Hoque, A., et al. 2024, ApJ, 961, 176, doi: 10.3847/1538-4357/ad0daa

    work page doi:10.3847/1538-4357/ad0daa 2024

  4. [5]

    O., Chuss, D

    Butterfield, N. O., Chuss, D. T., Guerra, J. A., et al. 2024a, ApJ, 963, 130, doi: 10.3847/1538-4357/ad12b9

    doi:10.3847/1538-4357/ad12b9

  5. [6]

    O., Guerra, J

    Butterfield, N. O., Guerra, J. A., Chuss, D. T., et al. 2024b, ApJ, 968, 63, doi: 10.3847/1538-4357/ad402c

    doi:10.3847/1538-4357/ad402c

  6. [7]

    J., Noriega-Crespo, A., Mizuno, D

    Carey, S. J., Noriega-Crespo, A., Mizuno, D. R., et al. 2009, PASP, 121, 76, doi: 10.1086/596581

    doi:10.1086/596581 2009

  7. [8]

    2016, PhRvD, 94, 063504, doi: 10.1103/PhysRevD.94.063504

    Carlson, E., Linden, T., & Profumo, S. 2016, PhRvD, 94, 063504, doi: 10.1103/PhysRevD.94.063504

    work page doi:10.1103/physrevd.94.063504 2016

  8. [9]

    1975, ApJL, 200, L107, doi: 10.1086/181908

    Castor, J., McCray, R., & Weaver, R. 1975, ApJL, 200, L107, doi: 10.1086/181908

    doi:10.1086/181908 1975

Show all 85 references
  1. [10]

    1953, ApJ, 118, 113, doi: 10.1086/145731

    Chandrasekhar, S., & Fermi, E. 1953, ApJ, 118, 113, doi: 10.1086/145731

    1953 doi

  2. [11]

    2021, A&A, 649, A43, doi: 10.1051/0004-6361/202039205

    Lohr, M. 2021, A&A, 649, A43, doi: 10.1051/0004-6361/202039205

    2021 doi

  3. [12]

    E., Peek, J

    Clark, S. E., Peek, J. E. G., & Putman, M. E. 2014, ApJ, 789, 82, doi: 10.1088/0004-637X/789/1/82

    2014 doi

  4. [13]

    J., & Ransom, S

    Condon, J. J., & Ransom, S. M. 2016, Essential Radio Astronomy

    2016

  5. [14]

    Protheroe, R. J. 2010, Nature, 463, 65, doi: 10.1038/nature08635

    2010 doi

  6. [15]

    C., et al

    Crowe, S., Fedriani, R., Tan, J. C., et al. 2024, arXiv e-prints, arXiv:2410.09253, doi: 10.48550/arXiv.2410.09253

    2024 doi arXiv

  7. [16]

    Crowther, P. A. 2007, ARA&A, 45, 177, doi: 10.1146/annurev.astro.45.051806.110615

    2007 arXiv

  8. [17]

    Crutcher, R. M. 2012, ARA&A, 50, 29, doi: 10.1146/annurev-astro-081811-125514

    2012 doi

  9. [18]

    D., Cotera, A., et al

    Dong, H., Wang, Q. D., Cotera, A., et al. 2011, MNRAS, 417, 114, doi: 10.1111/j.1365-2966.2011.19013.x

    2011

  10. [19]

    Draine, B. T. 2011, Physics of the Interstellar and Intergalactic Medium Ferri` ere, K. 2009, A&A, 505, 1183, doi: 10.1051/0004-6361/200912617 Ferri` ere, K., Gillard, W., & Jean, P. 2007, A&A, 467, 611, doi: 10.1051/0004-6361:20066992

    2011 doi

  11. [20]

    A., Drechsler, M., Strottner, X., et al

    Fesen, R. A., Drechsler, M., Strottner, X., et al. 2024, ApJS, 272, 36, doi: 10.3847/1538-4365/ad410a

    2024 doi

  12. [21]

    Fitzpatrick, E. L. 1999, PASP, 111, 63, doi: 10.1086/316293

    1999 doi

  13. [22]

    K., Gillessen, S., Dodds-Eden, K., et al

    Fritz, T. K., Gillessen, S., Dodds-Eden, K., et al. 2011, ApJ, 737, 73, doi: 10.1088/0004-637X/737/2/73

    2011 doi

  14. [23]

    2016, A&A, 586, A50, doi: 10.1051/0004-6361/201526100

    Ginsburg, A., Henkel, C., Ao, Y., et al. 2016, A&A, 586, A50, doi: 10.1051/0004-6361/201526100

    2016 doi

  15. [24]

    Pauldrach, A. W. A. 2002, ApJ, 566, 880, doi: 10.1086/338125

    2002 doi

  16. [25]

    E., Hensley, B

    Guan, Y., Clark, S. E., Hensley, B. S., et al. 2021, ApJ, 920, 6, doi: 10.3847/1538-4357/ac133f

    2021 doi

  17. [26]

    M., Reynolds, R

    Haffner, L. M., Reynolds, R. J., Tufte, S. L., et al. 2003, ApJS, 149, 405, doi: 10.1086/378850

    2003 doi

  18. [27]

    J., Lau, R

    Hankins, M. J., Lau, R. M., Radomski, J. T., et al. 2020, ApJ, 894, 55, doi: 10.3847/1538-4357/ab7c5d

    2020 doi

  19. [28]

    2019, Frontiers in Astronomy and Space Sciences, 6, 5, doi: 10.3389/fspas.2019.00005

    Hennebelle, P., & Inutsuka, S.-i. 2019, Frontiers in Astronomy and Space Sciences, 6, 5, doi: 10.3389/fspas.2019.00005

    2019

  20. [29]

    D., Barnes, A

    Henshaw, J. D., Barnes, A. T., Battersby, C., et al. 2023, in Astronomical Society of the Pacific Conference Series, Vol. 534, Protostars and Planets VII, ed. S. Inutsuka, Y. Aikawa, T. Muto, K. Tomida, & M. Tamura, 83, doi: 10.48550/arXiv.2203.11223

    2023 doi arXiv

  21. [30]

    2022, ApJ, 925, 165, doi: 10.3847/1538-4357/ac449a

    Heywood, I., Rammala, I., Camilo, F., et al. 2022, ApJ, 925, 165, doi: 10.3847/1538-4357/ac449a

    2022 doi

  22. [31]

    Hu, Y., Lazarian, A., & Wang, Q. D. 2022, MNRAS, 513, 3493, doi: 10.1093/mnras/stac1060 Ib´ a˜ nez-Mej ´ ıa, J. C., Mac Low, M.-M., & Klessen, R. S. 2022, ApJ, 925, 196, doi: 10.3847/1538-4357/ac3b58

    2022 doi

  23. [32]

    L., Hill, R., Scott, D., et al

    Jow, D. L., Hill, R., Scott, D., et al. 2018, MNRAS, 474, 1018, doi: 10.1093/mnras/stx2736

    2018 doi

  24. [33]

    2013, ApJL, 775, L50, doi: 10.1088/2041-8205/775/2/L50

    Kendrew, S., Ginsburg, A., Johnston, K., et al. 2013, ApJL, 775, L50, doi: 10.1088/2041-8205/775/2/L50

    2013 doi

  25. [34]

    W., & Rosolowsky, E

    Koch, E. W., & Rosolowsky, E. W. 2015, MNRAS, 452, 3435, doi: 10.1093/mnras/stv1521

    2015 doi

  26. [35]

    Kruijssen, J. M. D., Longmore, S. N., Elmegreen, B. G., et al. 2014, MNRAS, 440, 3370, doi: 10.1093/mnras/stu494

    2014 doi

  27. [36]

    R., Stone, J

    Krumholz, M. R., Stone, J. M., & Gardiner, T. A. 2007, ApJ, 671, 518, doi: 10.1086/522665

    2007 doi

  28. [37]

    C., Goss, W

    Lang, C. C., Goss, W. M., Cyganowski, C., & Clubb, K. I. 2010, ApJS, 191, 275, doi: 10.1088/0067-0049/191/2/275

    2010 doi

  29. [38]

    R., & Oskinova, L

    Liermann, A., Hamann, W. R., & Oskinova, L. M. 2012, A&A, 540, A14, doi: 10.1051/0004-6361/201117534

    2012 doi

  30. [39]

    S., & Spiker, R

    Liszt, H. S., & Spiker, R. W. 1995, ApJS, 98, 259, doi: 10.1086/192160

    1995 doi

  31. [40]

    2020, ApJL, 894, L14, doi: 10.3847/2041-8213/ab8b65

    Lu, X., Cheng, Y., Ginsburg, A., et al. 2020, ApJL, 894, L14, doi: 10.3847/2041-8213/ab8b65

    2020 doi

  32. [41]

    2022, Nature Astronomy, 6, 837, doi: 10.1038/s41550-022-01681-4

    Lu, X., Li, G.-X., Zhang, Q., & Lin, Y. 2022, Nature Astronomy, 6, 837, doi: 10.1038/s41550-022-01681-4

    2022 doi

  33. [42]

    Lu, X., Mills, E. A. C., Ginsburg, A., et al. 2019, ApJS, 244, 35, doi: 10.3847/1538-4365/ab4258

    2019 doi

  34. [43]

    2021, ApJ, 909, 177, doi: 10.3847/1538-4357/abde3c

    Lu, X., Li, S., Ginsburg, A., et al. 2021, ApJ, 909, 177, doi: 10.3847/1538-4357/abde3c

    2021 doi

  35. [44]

    2024, ApJ, 962, 39, doi: 10.3847/1538-4357/ad1395 24 Bally et al

    Lu, X., Liu, J., Pillai, T., et al. 2024, ApJ, 962, 39, doi: 10.3847/1538-4357/ad1395 24 Bally et al

    2024 doi

  36. [45]

    Mackey, J., & Lim, A. J. 2011, MNRAS, 412, 2079, doi: 10.1111/j.1365-2966.2010.18043.x

    2011

  37. [46]

    P., et al

    Mangilli, A., Aumont, J., Bernard, J. P., et al. 2019, A&A, 630, A74, doi: 10.1051/0004-6361/201935072

    2019 doi

  38. [47]

    2019, A&A, 630, A73, doi: 10.1051/0004-6361/201935920

    Meng, F., S´ anchez-Monge,´A., Schilke, P., et al. 2019, A&A, 630, A73, doi: 10.1051/0004-6361/201935920

    2019 doi

  39. [48]

    G., & Henderson, A

    Mezger, P. G., & Henderson, A. P. 1967, ApJ, 147, 471, doi: 10.1086/149030

    1967 doi

  40. [49]

    2011, ApJL, 735, L33, doi: 10.1088/2041-8205/735/2/L33

    Molinari, S., Bally, J., Noriega-Crespo, A., et al. 2011, ApJL, 735, L33, doi: 10.1088/2041-8205/735/2/L33

    2011 doi

  41. [50]

    2007, arXiv e-prints, astro, doi: 10.48550/arXiv.astro-ph/0701050

    Morris, M. 2007, arXiv e-prints, astro, doi: 10.48550/arXiv.astro-ph/0701050

    2007 doi arXiv

  42. [51]

    E., & Smith, R

    Mullens, E., Zucker, C., Murray, C. E., & Smith, R. 2024, ApJ, 966, 127, doi: 10.3847/1538-4357/ad306a

    2024 doi

  43. [52]

    2009, PASJ, 61, 283, doi: 10.1093/pasj/61.2.283

    Nagayama, T., Sato, S., Nishiyama, S., et al. 2009, PASJ, 61, 283, doi: 10.1093/pasj/61.2.283

    2009 doi

  44. [53]

    1991, A&A, 241, L33

    Mauersberger, R. 1991, A&A, 241, L33

    1991

  45. [54]

    2009, ApJ, 696, 1407, doi: 10.1088/0004-637X/696/2/1407

    Nishiyama, S., Tamura, M., Hatano, H., et al. 2009, ApJ, 696, 1407, doi: 10.1088/0004-637X/696/2/1407

    2009 doi

  46. [55]

    2010, ApJL, 722, L23, doi: 10.1088/2041-8205/722/1/L23

    Nishiyama, S., Hatano, H., Tamura, M., et al. 2010, ApJL, 722, L23, doi: 10.1088/2041-8205/722/1/L23

    2010 doi

  47. [56]

    2024, A&A, 681, L21, doi: 10.1051/0004-6361/202348712 O’Dell, C

    Nogueras-Lara, F. 2024, A&A, 681, L21, doi: 10.1051/0004-6361/202348712 O’Dell, C. R. 2001, ARA&A, 39, 99, doi: 10.1146/annurev.astro.39.1.99

    2024 doi

  48. [57]

    R., Goto, M., et al

    Oka, T., Geballe, T. R., Goto, M., et al. 2019, ApJ, 883, 54, doi: 10.3847/1538-4357/ab3647

    2019 doi

  49. [58]

    2019, A&A, 630, A72, doi: 10.1051/0004-6361/201935919

    Padovani, M., Marcowith, A., S´ anchez-Monge,´A., Meng, F., & Schilke, P. 2019, A&A, 630, A72, doi: 10.1051/0004-6361/201935919

    2019 doi

  50. [59]

    2024, ApJ, 972, 30, doi: 10.3847/1538-4357/ad5aea Par´ e, D., Butterfield, N

    Pan, X., Zhang, Q., Qiu, K., et al. 2024, ApJ, 972, 30, doi: 10.3847/1538-4357/ad5aea Par´ e, D., Butterfield, N. O., Chuss, D. T., et al. 2024, ApJ, 969, 150, doi: 10.3847/1538-4357/ad4462

    2024 doi

  51. [60]

    2019, Frontiers in Astronomy and Space Sciences, 6, 15, doi: 10.3389/fspas.2019.00015

    Pattle, K., & Fissel, L. 2019, Frontiers in Astronomy and Space Sciences, 6, 15, doi: 10.3389/fspas.2019.00015

    2019

  52. [61]

    2023, in Astronomical Society of the Pacific Conference

    Pattle, K., Fissel, L., Tahani, M., Liu, T., & Ntormousi, E. 2023, in Astronomical Society of the Pacific Conference

    2023

  53. [62]

    534, Protostars and Planets VII, ed

    Series, Vol. 534, Protostars and Planets VII, ed. S. Inutsuka, Y. Aikawa, T. Muto, K. Tomida, & M. Tamura, 193, doi: 10.48550/arXiv.2203.11179

    doi arXiv

  54. [63]

    2018, ApJL, 860, L6, doi: 10.3847/2041-8213/aac771

    Pattle, K., Ward-Thompson, D., Hasegawa, T., et al. 2018, ApJL, 860, L6, doi: 10.3847/2041-8213/aac771

    2018 doi

  55. [64]

    C., et al

    Pillai, T., Kauffmann, J., Tan, J. C., et al. 2015, ApJ, 799, 74, doi: 10.1088/0004-637X/799/1/74

    2015 doi

  56. [65]

    J., Menten, K

    Reid, M. J., Menten, K. M., Brunthaler, A., et al. 2019, ApJ, 885, 131, doi: 10.3847/1538-4357/ab4a11

    2019 doi

  57. [66]

    Simpson, J. P. 2018, ApJ, 857, 59, doi: 10.3847/1538-4357/aab55b

    2018 doi

  58. [67]

    2023, MNRAS, 518, 6273, doi: 10.1093/mnras/stac3137

    Sofue, Y. 2023, MNRAS, 518, 6273, doi: 10.1093/mnras/stac3137

    2023 doi

  59. [68]

    D., & Hennebelle, P

    Soler, J. D., & Hennebelle, P. 2017, A&A, 607, A2, doi: 10.1051/0004-6361/201731049

    2017 doi

  60. [69]

    C., Magorrian, J., Nogueras-Lara, F., et al

    Sormani, M. C., Magorrian, J., Nogueras-Lara, F., et al. 2020, MNRAS, 499, 7, doi: 10.1093/mnras/staa2785

    2020 doi

  61. [70]

    C., Treß, R

    Sormani, M. C., Treß, R. G., Ridley, M., et al. 2018, MNRAS, 475, 2383, doi: 10.1093/mnras/stx3258

    2018 doi

  62. [71]

    C., Sanders, J

    Sormani, M. C., Sanders, J. L., Fritz, T. K., et al. 2022, MNRAS, 512, 1857, doi: 10.1093/mnras/stac639

    2022 doi

  63. [72]

    2024, ApJ, 968, 131, doi: 10.3847/1538-4357/ad40a6

    Tachihara, K., Fukaya, N., Tokuda, K., et al. 2024, ApJ, 968, 131, doi: 10.3847/1538-4357/ad40a6

    2024 doi

  64. [73]

    G., Sormani, M

    Tress, R. G., Sormani, M. C., Girichidis, P., et al. 2024, arXiv e-prints, arXiv:2403.13048, doi: 10.48550/arXiv.2403.13048 Van Eck, C. L., Brown, J. C., Stil, J. M., et al. 2011, ApJ, 728, 97, doi: 10.1088/0004-637X/728/2/97

    2024 doi arXiv

  65. [74]

    1977, ApJ, 218, 377, doi: 10.1086/155692

    Weaver, R., McCray, R., Castor, J., Shapiro, P., & Moore, R. 1977, ApJ, 218, 377, doi: 10.1086/155692

    1977 doi

  66. [75]

    E., Wilson, T

    Wink, J. E., Wilson, T. L., & Bieging, J. H. 1983, A&A, 127, 211

    1983

  67. [76]

    1990, ApJL, 361, L19, doi: 10.1086/185817 —

    Yusef-Zadeh, F. 1990, ApJL, 361, L19, doi: 10.1086/185817 —. 2003, ApJ, 598, 325, doi: 10.1086/378715

    1990 doi

  68. [77]

    G., & Wardle, M

    Yusef-Zadeh, F., Arendt, R. G., & Wardle, M. 2022a, ApJL, 939, L21, doi: 10.3847/2041-8213/ac982a

    doi

  69. [78]

    G., Wardle, M., et al

    Yusef-Zadeh, F., Arendt, R. G., Wardle, M., et al. 2022b, MNRAS, 515, 3059, doi: 10.1093/mnras/stac1696

    doi

  70. [79]

    G., Wardle, M., & Heywood, I

    Yusef-Zadeh, F., Arendt, R. G., Wardle, M., & Heywood, I. 2023, ApJL, 949, L31, doi: 10.3847/2041-8213/acd54b

    2023 doi

  71. [80]

    G., Wardle, M., Heywood, I., & Cotton, W

    Yusef-Zadeh, F., Arendt, R. G., Wardle, M., Heywood, I., & Cotton, W. 2022c, MNRAS, 517, 294, doi: 10.1093/mnras/stac2415

    doi

  72. [81]

    G., Wardle, M., et al

    Yusef-Zadeh, F., Arendt, R. G., Wardle, M., et al. 2022d, ApJL, 925, L18, doi: 10.3847/2041-8213/ac4802

    doi

  73. [82]

    W., & Cotton, W

    Yusef-Zadeh, F., Hewitt, J. W., & Cotton, W. 2004, ApJS, 155, 421, doi: 10.1086/425257

    2004 doi

  74. [83]

    1984, Nature, 310, 557, doi: 10.1038/310557a0

    Yusef-Zadeh, F., Morris, M., & Chance, D. 1984, Nature, 310, 557, doi: 10.1038/310557a0

    1984 doi

  75. [84]

    2024, MNRAS, 530, 254, doi: 10.1093/mnras/stae549

    Yusef-Zadeh, F., Zhao, J.-H., Arendt, R., et al. 2024, MNRAS, 530, 254, doi: 10.1093/mnras/stae549

    2024 doi

  76. [85]

    W., Arendt, R

    Yusef-Zadeh, F., Hewitt, J. W., Arendt, R. G., et al. 2009, ApJ, 702, 178, doi: 10.1088/0004-637X/702/1/178 Zamora-Avil´ es, M., V´ azquez-Semadeni, E., Gonz´ alez, R. F., et al. 2019, MNRAS, 487, 2200, doi: 10.1093/mnras/stz1235

    2009 doi

  77. [86]

    W., Dib, S., Juvela, M., et al

    Zhou, J. W., Dib, S., Juvela, M., et al. 2024, A&A, 686, A146, doi: 10.1051/0004-6361/202449514 Magnetic HII Regions 25 Figure 7. A finder chart showing the locations of the next six figures, labeled from A1 to A6. APPENDIX A. GALLERY OF MAGNIFIED VIEWS OF THE SGR C H ii REGIO...

    2024 doi

Pith tools

Reviewed August 11, 2026 · model on record in the stance chip above.