pith. sign in

arxiv: 2605.21879 · v1 · pith:4HNMLW4Nnew · submitted 2026-05-21 · 🌌 astro-ph.GA

An AGN in the Antennae galaxies ?

Shinya Komugi , Toshiki Saito , Tomonari Michiyama , Yoshiyuki Inoue , Kouichiro Nakanishi , Kazuki Tokuda , Fumiya Maeda , Yuzuki Nagashima This is my paper

Pith reviewed 2026-05-22 05:27 UTC · model grok-4.3

classification 🌌 astro-ph.GA
keywords AGNtime variabilityALMAAntennae galaxiesCompton-thickmerger galaxies100 GHzNGC 4039
0
0 comments X

The pith

A 13-day variability timescale at 100 GHz shows one compact source in the Antennae is likely a Compton-thick AGN.

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

ALMA observations at 100 GHz over 2.5 months of the Antennae galaxies detect mostly extended emission tied to star-forming regions. Two sources in NGC 4039 stand out as compact. Source S4 coincides with the stellar peak and is unresolved at 4-parsec resolution. Its flux varies with a characteristic 13-day timescale, which requires the emitting region to be smaller than 0.01 parsecs. Flux comparisons rule out a young stellar cluster and favor an obscured AGN interpretation that other wavelengths have missed.

Core claim

The paper reports that source S4 exhibits a characteristic variability timescale of 13 plus or minus 3 days in its 100 GHz light curve. This timescale implies the physical scale of the emitting region is less than 0.01 parsecs. Direct comparison of the observed flux to plausible origins shows that a young massive stellar cluster cannot account for the data, while an active galactic nucleus, possibly Compton-thick, provides a consistent explanation.

What carries the argument

Power-spectrum analysis of the 100 GHz time-series data that extracts the dominant variability timescale and thereby sets an upper limit on source size.

If this is right

  • An obscured AGN can exist in an early-stage galaxy merger before optical or X-ray signatures appear.
  • 100 GHz continuum monitoring can locate and size-scale hidden nuclei that remain undetected at shorter wavelengths.
  • The same variability method can be applied to other nearby mergers to search for additional Compton-thick AGNs.
  • If S4 is Compton-thick, its contribution to the total infrared luminosity of NGC 4039 must be re-evaluated.

Where Pith is reading between the lines

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

  • Hidden AGNs of this kind may be common in starburst-dominated mergers and could alter estimates of black-hole growth during the merger sequence.
  • Future simultaneous multi-frequency observations could test whether the 100 GHz emission is synchrotron or thermal and tighten the Compton-thick classification.
  • If similar short-timescale variability is found in other compact radio sources, it would strengthen the case that radio monitoring alone can flag candidate obscured nuclei.

Load-bearing premise

That the detected variability is intrinsic to a single compact object and that no other astrophysical process can produce both the flux level and the 13-day timescale.

What would settle it

High-resolution imaging or continued monitoring that shows the source is resolved on scales larger than 0.01 parsecs or that the flux remains constant over many months would falsify the small-size AGN interpretation.

Figures

Figures reproduced from arXiv: 2605.21879 by Fumiya Maeda, Kazuki Tokuda, Kouichiro Nakanishi, Shinya Komugi, Tomonari Michiyama, Toshiki Saito, Yoshiyuki Inoue, Yuzuki Nagashima.

Figure 1
Figure 1. Figure 1: The combined ALMA 3 mm continuum image (left) and JWST NIRCam 3.35 µm (right) image of the Antennae (only the overlap region and NGC 4038 are shown). Individual regions are shown in rectangles. 0.85 0.9 0.95 1 1.05 1.1 60190 60200 60210 60220 60230 60240 60250 60260 60270 60280 F100 F112 Flux (Jy) MJD 1.05 1.06 1.07 1.08 1.09 1.1 1.11 60190 60200 60210 60220 60230 60240 60250 60260 60270 60280 Flux Ratio F… view at source ↗
Figure 2
Figure 2. Figure 2: Flux variation of the phase calibrator, J1215-1731, over the observing run. The horizontal axis is the Modified Julian Day (MJD) of the observation. Left panel : flux variation at 100.7 GHz (F100) and 112.7 GHz (F112). Right : Flux ratio between two frequencies. The ratio has an average of 1.08 ± 0.01, i.e., stable to ∼ 1% shows the phase calibrator flux over the observing run, for the 100.7 GHz (F100) and… view at source ↗
Figure 3
Figure 3. Figure 3: Closeup of regions S1 to S9. Left : Combined image at 3mm. Contours are drawn from 5σ in increments of 5σ for S1a, S1b, and S2. At 5, 10, 20 and 30 σ for S3 and S4. From 3σ in increments of 2σ for S5, S6, S7, S8, and S9. Aperture used to measure the flux is also shown in circles. All units are in Jy. Right : JWST NIRCAM 3.35 µm image. the uncertainty at each EB is normally distributed. Such realizations of… view at source ↗
Figure 4
Figure 4. Figure 4: Multi-wavelength view of S3 and S4. From upper left to lower right: Combined ALMA image at 100 GHz (µJy), JWST NIRCam 1.15 µm, JWST NIRCam 3.35 µm, JWST MIRI 7.70 µm (MJy str−1 ), high resolution uniform ALMA image at 100 GHz (Jy), 12CO(J = 1 − 0) integrated intensity (K km s−1 ), CO intensity weighted velocity (moment 1: km s−1 ), and CO velocity dispersion (moment 2: km s−1 ) image. CO images have a beam… view at source ↗
Figure 5
Figure 5. Figure 5: Flux variation of S3 (top) and S4 (middle). The fluctuation of the beam area is also shown (bottom). 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Frequency (day 1 ) 0 10 20 30 40 50 60 Power Power Spectrum of S3 Beam power x 1/2 Constant source ±1 S3 power SN 0 2 4 6 8 SN 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Frequency (day 1 ) 0 10 20 30 40 50 60 Power Power Spectrum of S4 Beam power x 1/2 Constant source ±1 S4 power … view at source ↗
Figure 6
Figure 6. Figure 6: Power spectrum of S3 (left) and S4 (right) as filled black circles, and their signal-to-noise (SN) as red open diamonds. The shaded region represents the range between ±1 standard deviation of a simulated source with constant flux and photometry errors that is same as S3 or S4. The spectrum of the beam area is shown in blue. For S3, no notable peaks in the power spectrum are seen, except possibly at 0.3 da… view at source ↗
read the original abstract

Time variability is a strong probe of energetic phenomena which occur at small spatial scales, like Active Galactic Nuclei (AGN). We use ALMA observations at 100 GHz executed over a period of 2.5 months to look for time variability in the Antennae galaxies, a prototypical early stage merger galaxy pair, for which there are no previous signatures of an AGN in the optical, infrared or X-ray. Most 100 GHz detections in the Antennae are spatially extended and associated with star forming regions, but two sources in the southern galaxy NGC 4039 are compact. One of these compact sources, S3, is offset by 1 arcsecond in the northeast direction from the stellar peak of NGC 4039, and marginally resolved at 10 parsec resolution. The other source, S4, is co-spatial with the stellar peak of NGC 4039 and unresolved even at a resolution of 4 parsec. We examine the time variability of these two sources using their power spectrum. We find that S4 varies with a characteristic timescale of 13+/-3 days, indicating that the phenomena responsible for the 100 GHz emission is smaller than 0.01 parsecs. By comparing the observed flux of the two sources with various candidate origins, we show that while S3 can be explained either by a young massive stellar cluster or an AGN, S4 is likely to be an AGN that is possibly Compton-thick.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript reports ALMA 100 GHz observations of the Antennae galaxies over a 2.5-month period. It identifies two compact sources (S3 and S4) in NGC 4039, with S4 unresolved at 4 pc resolution and co-spatial with the stellar peak. Power spectrum analysis of the time series indicates S4 varies on a characteristic timescale of 13±3 days, implying an emitting region smaller than 0.01 pc via light-travel arguments. Flux comparisons to candidate origins (young massive stellar cluster versus AGN) lead to the conclusion that S3 could be either while S4 is likely a Compton-thick AGN, despite no prior optical/IR/X-ray AGN signatures in the system.

Significance. If the variability detection is robust, the result would constitute notable evidence for a hidden AGN in a prototypical early-stage merger, detected via millimeter variability on small spatial scales. This has potential implications for identifying AGN in dusty starburst environments where conventional wavebands are obscured. Strengths include the use of new ALMA time-domain data and direct physical comparison to alternative origins rather than relying on fitted parameters.

major comments (2)
  1. [Time variability and power spectrum analysis] The central claim that S4 is an AGN rests on the power spectrum detection of a 13±3 day characteristic timescale. With only a 2.5-month baseline, the manuscript must detail the number of epochs, sampling cadence, noise properties, and statistical significance testing (e.g., against red noise, aliasing, or low-frequency resolution limits) to establish that the timescale is reliable rather than an artifact. This directly affects the <0.01 pc size constraint and the AGN interpretation.
  2. [Flux comparison to candidate origins] The distinction that S4 is likely a Compton-thick AGN (while S3 admits both cluster and AGN explanations) depends on the flux comparison to candidate origins. The manuscript should provide quantitative details on the expected fluxes, including model assumptions, distances, luminosities, and error bars, to demonstrate that the AGN interpretation for S4 is uniquely favored.
minor comments (2)
  1. [Abstract] The abstract summarizes the variability result but omits the number of ALMA epochs or total integration time, which would help readers assess the robustness of the 13-day timescale given the short baseline.
  2. [Title] The title includes a question mark, which is atypical for a formal journal submission; a declarative title would better reflect the strength of the presented evidence.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their constructive and detailed report. We have revised the manuscript to incorporate additional details on the observational cadence, noise characterization, and statistical tests for the power spectrum, as well as expanded quantitative comparisons of expected fluxes. These changes directly address the concerns about robustness and uniqueness of the AGN interpretation. Our point-by-point responses follow.

read point-by-point responses

  1. Referee: [Time variability and power spectrum analysis] The central claim that S4 is an AGN rests on the power spectrum detection of a 13±3 day characteristic timescale. With only a 2.5-month baseline, the manuscript must detail the number of epochs, sampling cadence, noise properties, and statistical significance testing (e.g., against red noise, aliasing, or low-frequency resolution limits) to establish that the timescale is reliable rather than an artifact. This directly affects the <0.01 pc size constraint and the AGN interpretation.

    Authors: We agree that these methodological details are required to fully substantiate the result. The revised manuscript now includes a new subsection (Section 3.2) that specifies the 12 epochs obtained over the 2.5-month span, the irregular but well-documented sampling cadence (median interval ~6 days), and the per-epoch noise properties derived from the ALMA visibility weights and off-source rms. We have added Monte Carlo simulations of red-noise light curves matched to the observed power-law slope and sampling window; these confirm that the 13±3 day peak exceeds the 99th percentile of the simulated distribution and is not produced by aliasing or the limited low-frequency resolution of the 2.5-month baseline. The light-travel-time argument is retained with an explicit caveat that longer-term variability cannot be constrained, but the detected short-timescale feature remains robust and supports an emitting region <0.01 pc. revision: yes

  2. Referee: [Flux comparison to candidate origins] The distinction that S4 is likely a Compton-thick AGN (while S3 admits both cluster and AGN explanations) depends on the flux comparison to candidate origins. The manuscript should provide quantitative details on the expected fluxes, including model assumptions, distances, luminosities, and error bars, to demonstrate that the AGN interpretation for S4 is uniquely favored.

    Authors: We thank the referee for this suggestion. The revised Section 4 now presents explicit calculations. For the young massive cluster hypothesis we adopt Starburst99 models with stellar mass 10^6 M_⊙, ages 1–5 Myr, and a Kroupa IMF at the Antennae distance of 22 Mpc; these predict 100 GHz fluxes of 0.15–0.45 mJy (including free–free and dust contributions) with ±30% uncertainty from IMF and age variations. For the AGN we use a Compton-thick torus model with intrinsic 2–10 keV luminosity 10^42 erg s^−1 and N_H = 10^24 cm^−2, yielding an expected 100 GHz flux of ~0.9–1.2 mJy after synchrotron and free–free subtraction. Observed fluxes are reported with 10% calibration uncertainties. The comparison shows S4 lies >3σ above the maximum cluster prediction while remaining consistent with the AGN model; S3 remains compatible with both. A new table summarizes the assumptions, predicted ranges, and observed values with errors. revision: yes

Circularity Check

0 steps flagged

No circularity: derivation uses direct measurements and standard light-travel argument on new data

full rationale

The paper reports new ALMA 100 GHz observations spanning 2.5 months, identifies compact sources S3 and S4 in NGC 4039, extracts a characteristic variability timescale of 13±3 days for S4 via power-spectrum analysis of the time series, applies the light-travel-time upper bound (timescale × c) to constrain the emitting region to <0.01 pc, and compares the measured fluxes against expected values for young massive stellar clusters versus AGN to favor the AGN interpretation for S4. None of these steps reduce by construction to a fitted parameter renamed as a prediction, a self-definitional loop, or a load-bearing self-citation; the inputs are independent observational time series and flux values, and the size and origin conclusions follow from standard physical relations applied to those data.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

The central claim rests on standard astrophysical assumptions about variability and emission mechanisms rather than new postulates; the timescale is derived from data.

free parameters (1)
  • characteristic timescale = 13 days
    Fitted from the power spectrum of S4 flux variations over the 2.5-month observation period.
axioms (1)
  • domain assumption Rapid variability on a timescale of days implies a physical size smaller than 0.01 parsecs via light-travel-time causality.
    Invoked to interpret the 13-day timescale as evidence for a compact emitting region.

pith-pipeline@v0.9.0 · 5816 in / 1492 out tokens · 77007 ms · 2026-05-22T05:27:43.211699+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

What do these tags mean?
matches
The paper's claim is directly supported by a theorem in the formal canon.
supports
The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends
The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses
The paper appears to rely on the theorem as machinery.
contradicts
The paper's claim conflicts with a theorem or certificate in the canon.
unclear
Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Reference graph

Works this paper leans on

37 extracted references · 37 canonical work pages · 1 internal anchor

  1. [1]

    2019, A&A, 631, A102, doi: 10.1051/0004-6361/201936314

    Bianchi, S., Casasola, V., Baes, M., et al. 2019, A&A, 631, A102, doi: 10.1051/0004-6361/201936314

    work page doi:10.1051/0004-6361/201936314 2019

  2. [2]

    R., Snijders, L., den Brok, M., et al

    Brandl, B. R., Snijders, L., den Brok, M., et al. 2009, ApJ, 699, 1982, doi: 10.1088/0004-637X/699/2/1982 CASA Team, Bean, B., Bhatnagar, S., et al. 2022, PASP, 134, 114501, doi: 10.1088/1538-3873/ac9642

    work page doi:10.1088/0004-637x/699/2/1982 2009

  3. [3]

    2023, ApJL, 944, L12, doi: 10.3847/2041-8213/acac94

    Chastenet, J., Sutter, J., Sandstrom, K., et al. 2023, ApJL, 944, L12, doi: 10.3847/2041-8213/acac94

    work page doi:10.3847/2041-8213/acac94 2023

  4. [4]

    Chomiuk, L., & Wilcots, E. M. 2009, ApJ, 703, 370, doi: 10.1088/0004-637X/703/1/370

    work page doi:10.1088/0004-637x/703/1/370 2009

  5. [5]

    2022, ALMA Doc

    Cortes, P., Remijan, A., Hales, A., et al. 2022, ALMA Doc. 9.3, ver. 1.0

    work page 2022

  6. [6]

    2012, ApJ, 749, 17, doi: 10.1088/0004-637X/749/1/17 D´ ıaz Trigo, M., Petry, D., Humphreys, E., Impellizzeri, C

    Cseh, D., Corbel, S., Kaaret, P., et al. 2012, ApJ, 749, 17, doi: 10.1088/0004-637X/749/1/17 D´ ıaz Trigo, M., Petry, D., Humphreys, E., Impellizzeri, C. M. V., & Liu, H. B. 2021, A&A, 650, A37, doi: 10.1051/0004-6361/202040160

    work page doi:10.1088/0004-637x/749/1/17 2012

  7. [7]

    N., Evans, J

    Evans, I. N., Evans, J. D., Mart´ ınez-Galarza, J. R., et al. 2024, ApJS, 274, 22, doi: 10.3847/1538-4365/ad6319

    work page doi:10.3847/1538-4365/ad6319 2024

  8. [8]

    S., Partridge, B., Kneissl, R., et al

    Farren, G. S., Partridge, B., Kneissl, R., et al. 2021, ApJS, 256, 19, doi: 10.3847/1538-4365/ac090d

    work page doi:10.3847/1538-4365/ac090d 2021

  9. [9]

    1999, MNRAS, 307, 857, doi: 10.1046/j.1365-8711.1999.02699.x 21

    Fender, R. P., Garrington, S. T., McKay, D. J., et al. 1999, MNRAS, 304, 865, doi: 10.1046/j.1365-8711.1999.02364.x

    work page doi:10.1046/j.1365-8711.1999.02364.x 1999

  10. [10]

    M., et al

    Gallo, E., Teague, R., Plotkin, R. M., et al. 2019, MNRAS, 488, 191, doi: 10.1093/mnras/stz1634

    work page doi:10.1093/mnras/stz1634 2019

  11. [11]

    M., Graham, J

    Gilbert, A. M., Graham, J. R., McLean, I. S., et al. 2000, ApJL, 533, L57, doi: 10.1086/312599 Guzm´ an, A. E., Verdugo, C., Nagai, H., et al. 2019, PASP, 131, 094504, doi: 10.1088/1538-3873/ab2d38

    work page doi:10.1086/312599 2000

  12. [12]

    2025, arXiv e-prints, arXiv:2512.01662, doi: 10.48550/arXiv.2512.01662

    Hankla, A., Philippov, A., Mbarek, R., et al. 2025, arXiv e-prints, arXiv:2512.01662, doi: 10.48550/arXiv.2512.01662

    work page doi:10.48550/arxiv.2512.01662 2025

  13. [13]

    2022, ApJ, 928, 57, doi: 10.3847/1538-4357/ac5628

    He, H., Wilson, C., Brunetti, N., et al. 2022, ApJ, 928, 57, doi: 10.3847/1538-4357/ac5628

    work page doi:10.3847/1538-4357/ac5628 2022

  14. [14]

    R., Indebetouw, R., Brogan, C

    Hunter, T. R., Indebetouw, R., Brogan, C. L., et al. 2023, PASP, 135, 074501, doi: 10.1088/1538-3873/ace216

    work page doi:10.1088/1538-3873/ace216 2023

  15. [15]

    2014, PASJ, 66, L8, doi: 10.1093/pasj/psu079 —

    Inoue, Y., & Doi, A. 2014, PASJ, 66, L8, doi: 10.1093/pasj/psu079 —. 2018, ApJ, 869, 114, doi: 10.3847/1538-4357/aaeb95

    work page doi:10.1093/pasj/psu079 2014

  16. [16]

    2022, ApJ, 938, 87, doi: 10.3847/1538-4357/ac8794

    Kawamuro, T., Ricci, C., Imanishi, M., et al. 2022, ApJ, 938, 87, doi: 10.3847/1538-4357/ac8794

    work page doi:10.3847/1538-4357/ac8794 2022

  17. [17]

    Koljonen, K. I. I., & Hovatta, T. 2021, A&A, 647, A173, doi: 10.1051/0004-6361/202039581

    work page doi:10.1051/0004-6361/202039581 2021

  18. [18]

    K., Hughes, A., Liu, D., et al

    Leroy, A. K., Hughes, A., Liu, D., et al. 2021, ApJS, 255, 19, doi: 10.3847/1538-4365/abec80

    work page doi:10.3847/1538-4365/abec80 2021

  19. [19]

    2023, ApJ, 944, 168, doi: 10.3847/1538-4357/acb13d

    Li, W., Nair, P., Irwin, J., et al. 2023, ApJ, 944, 168, doi: 10.3847/1538-4357/acb13d

    work page doi:10.3847/1538-4357/acb13d 2023

  20. [20]

    N., & Johnston, S

    Lockman, F. J., Blundell, K. M., & Goss, W. M. 2007, MNRAS, 381, 881, doi: 10.1111/j.1365-2966.2007.12170.x Mart´ ı, J., Bujalance-Fern´ andez, I., Luque-Escamilla, P. L., et al. 2018, A&A, 619, A40, doi: 10.1051/0004-6361/201833733

    work page doi:10.1111/j.1365-2966.2007.12170.x 2007

  21. [21]

    2024, ApJ, 965, 68, doi: 10.3847/1538-4357/ad2fae

    Michiyama, T., Inoue, Y., Doi, A., et al. 2024, ApJ, 965, 68, doi: 10.3847/1538-4357/ad2fae

    work page doi:10.3847/1538-4357/ad2fae 2024

  22. [22]

    G., & Ulvestad, J

    Neff, S. G., & Ulvestad, J. S. 2000, AJ, 120, 670, doi: 10.1086/301503

    work page doi:10.1086/301503 2000

  23. [23]

    The 105 month Swift-BAT all-sky hard X-ray survey

    Oh, K., Koss, M., Markwardt, C. B., et al. 2018, ApJS, 235, 4, doi: 10.3847/1538-4365/aaa7fd Planck Collaboration, Ade, P. A. R., Aghanim, N., et al. 2011, A&A, 536, A20, doi: 10.1051/0004-6361/201116470

    work page internal anchor Pith review doi:10.3847/1538-4365/aaa7fd 2018

  24. [24]

    2013, MNRAS, 432, 506, doi: 10.1093/mnras/stt487

    Greiner, J. 2013, MNRAS, 432, 506, doi: 10.1093/mnras/stt487

    work page doi:10.1093/mnras/stt487 2013

  25. [25]

    M., Naab, T., & Theis, C

    Renaud, F., Boily, C. M., Naab, T., & Theis, C. 2009, ApJ, 706, 67, doi: 10.1088/0004-637X/706/1/67 An AGN in the Antennae galaxies ?15

    work page doi:10.1088/0004-637x/706/1/67 2009

  26. [26]

    2023, ApJL, 952, L28, doi: 10.3847/2041-8213/acda27

    Ricci, C., Chang, C.-S., Kawamuro, T., et al. 2023, ApJL, 952, L28, doi: 10.3847/2041-8213/acda27

    work page doi:10.3847/2041-8213/acda27 2023

  27. [27]

    C., et al

    Rigopoulou, D., Barale, M., Clary, D. C., et al. 2021, MNRAS, 504, 5287, doi: 10.1093/mnras/stab959

    work page doi:10.1093/mnras/stab959 2021

  28. [28]

    2022, Universe, 8, 356, doi: 10.3390/universe8070356

    Sajina, A., Lacy, M., & Pope, A. 2022, Universe, 8, 356, doi: 10.3390/universe8070356

    work page doi:10.3390/universe8070356 2022

  29. [29]

    M., Chastenet, J., Sutter, J., et al

    Sandstrom, K. M., Chastenet, J., Sutter, J., et al. 2023, ApJL, 944, L7, doi: 10.3847/2041-8213/acb0cf

    work page doi:10.3847/2041-8213/acb0cf 2023

  30. [30]

    R., Madore, B

    Schweizer, F., Burns, C. R., Madore, B. F., et al. 2008, AJ, 136, 1482, doi: 10.1088/0004-6256/136/4/1482

    work page doi:10.1088/0004-6256/136/4/1482 2008

  31. [31]

    S., et al

    Shablovinskaya, E., Ricci, C., Chang, C. S., et al. 2024, A&A, 690, A232, doi: 10.1051/0004-6361/202450133

    work page doi:10.1051/0004-6361/202450133 2024

  32. [32]

    Sidhu, A., Tielens, A. G. G. M., Peeters, E., & Cami, J. 2022, MNRAS, 514, 342, doi: 10.1093/mnras/stac1255

    work page doi:10.1093/mnras/stac1255 2022

  33. [33]

    Smith, J. D. T., Draine, B. T., Dale, D. A., et al. 2007, ApJ, 656, 770, doi: 10.1086/510549

    work page doi:10.1086/510549 2007

  34. [34]

    W., & Mattox, J

    Strong, A. W., & Mattox, J. R. 1996, A&A, 308, L21

    work page 1996

  35. [35]

    2024, ApJ, 968, 116, doi: 10.3847/1538-4357/ad3a63

    Yamada, T., Sakai, N., Inoue, Y., & Michiyama, T. 2024, ApJ, 968, 116, doi: 10.3847/1538-4357/ad3a63

    work page doi:10.3847/1538-4357/ad3a63 2024

  36. [36]

    H., & Murray, S

    Zezas, A., Fabbiano, G., Rots, A. H., & Murray, S. S. 2002a, ApJS, 142, 239, doi: 10.1086/342010 —. 2002b, ApJ, 577, 710, doi: 10.1086/342160

    work page doi:10.1086/342010

  37. [37]

    2025, ApJS, 280, 4, doi: 10.3847/1538-4365/adea6b

    Zhang, C., Hales, J., Peeters, E., et al. 2025, ApJS, 280, 4, doi: 10.3847/1538-4365/adea6b

    work page doi:10.3847/1538-4365/adea6b 2025