Pith. sign in

REVIEW 2 major objections 5 minor 47 references

The central engine of low-luminosity radio galaxy 3C 270 (NGC 4261)

T0 review · 2 major / 5 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 3C 270's scattered light shows no hidden broad-line region or Big Blue Bump.

desk verdict Careful spectropolarimetry that turns a tentative broad-line detection into a robust non-detection, with a load-bearing assumption about template representativeness that should be softened in the abstract. read the letter →

arxiv 2412.10591 v3 pith:ZFVXYJNO submitted 2024-12-13 astro-ph.GA

Chengzhang Jiang , Robert Antonucci , Jose A. Acosta-Pulido , Patrick Ogle This is my paper · ORCID
classification astro-ph.GA
keywords spectropolarimetrylow-luminosityactivegalacticnucleiradiogalaxies3C270NGC4261hiddenbroad-lineregionbigbluebumpradiativelyinefficientaccretionflow
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

This paper uses deep optical spectropolarimetry of the low-luminosity radio galaxy 3C 270 (NGC 4261) to test whether its nucleus hides a standard accretion disk and broad-line region behind obscuring material. After correcting for interstellar polarization, both the continuum and the narrow emission lines are polarized at an angle perpendicular to the radio jet, which indicates that we are seeing the hidden nucleus through scattering. The polarized flux spectrum is well fit by narrow lines alone, and an injection test shows that over 94% of a sample of 37 real Seyfert 1 broad-line profiles would have been detected if present. The authors favor the conclusion that there is no hidden Big Blue Bump or broad-line region, and that the scattered continuum is instead dominated by a radiatively inefficient accretion flow and/or beamed synchrotron, making 3C 270 the third known case, after NGC 4258 and Centaurus A, where only narrow lines are scattered.

What carries the argument

The central observable is the polarized Stokes flux spectrum, which acts as a scattered-light view of the hidden nucleus. Two pieces of machinery carry the argument: an interstellar-polarization correction built from the nearby star HD 107289 and the Serkowski wavelength-dependent model, and an injection test that adds 37 real Seyfert 1 broad-line profiles, scaled by equivalent width to the measured polarized continuum, to see what fraction would be detected at signal-to-noise above 3. The polarization angles of the continuum, Hα, and [S II] being perpendicular to the radio jet anchors the scattering geometry. The Big Blue Bump is the thermal ultraviolet/optical excess expected from a standard radiatively efficient accretion disk, and the absence of such a component in scattered light is what the paper uses to rule out a hidden standard disk.

What would settle it

Take a deeper spectropolarimetric observation of 3C 270 reaching two to three times the current signal-to-noise in the polarized continuum; if a broad Hα component appears in the Stokes flux spectrum, the paper's central claim is wrong. Alternatively, rerun the injection test with a sample that includes narrow-line Seyfert 1 galaxies and low-equivalent-width profiles, and if a substantial fraction remain undetected, the 'over 94%' bound no longer rules out a hidden broad-line region.

Watch

Extended reading notes

Core claim

The central claim is that 3C 270's nucleus shows no evidence of a hidden standard accretion disk or hidden broad-line region when observed in scattered polarized light. The Stokes flux spectrum resembles the total flux spectrum and requires no broad component, and over 94% of a sample of luminous Seyfert 1 broad-line profiles would have been significantly detected if present in the polarized flux. The authors infer that the scattered continuum consists of radiatively inefficient accretion flow and/or beamed synchrotron radiation, while the scattered narrow lines come from the innermost narrow-line region. This places 3C 270 in the same class as NGC 4258 and Centaurus A, with the caveat that the scattered continuum is weakly detected, so a commensurate Big Blue Bump and broad-line region cannot be completely ruled out.

Load-bearing premise

The load-bearing premise is that the 37 luminous quasar broad-line profiles used in the injection test are representative of every broad-line profile a hidden broad-line region in 3C 270 could produce; if that region produced an atypical narrow, weak, or asymmetric line, it could escape detection, with the single nearby star used for interstellar-polarization correction adding a smaller secondary uncertainty.

Editorial extensions

If this is right

  • If correct, 3C 270 does not contain a hidden thermal accretion disk, so the warm mid-infrared dust seen in this galaxy cannot be powered by a Big Blue Bump heating a compact torus.
  • The apparent conflict between a high X-ray column density and low optical extinction is resolved if the optical light reaches us through a scattering mirror rather than directly.
  • The accretion flow in 3C 270 would be radiatively inefficient or jet-dominated rather than a standard thin disk, consistent with its very low Eddington ratio.
  • Spectropolarimetry would become the key observational test for identifying low-luminosity active galactic nuclei that genuinely lack hidden broad-line regions.

Reading between the lines

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

  • An implication the authors leave implicit is that 3C 270 becomes a test case for the theoretical prediction that the broad-line region disappears at low Eddington ratios, even though the warm dust detection complicates the companion prediction that the torus vanishes with it.
  • The injection test could be extended to narrow-line Seyfert 1 profiles and strongly asymmetric or very weak-lined profiles; if a meaningful fraction of those escaped detection, the 'fewer than 6% undetected' statistic would need to be revised.
  • A direct way to sharpen the conclusion would be ultraviolet spectropolarimetry: broad Lyα or C IV emission from a hidden disk might appear in scattered light even where optical Hα is diluted by the narrow-line region and scattered continuum.
  • The interstellar-polarization correction rests on a single proxy star; checking it against several nearby stars or tomographic dust maps would show whether the continuum polarization angle could shift enough to weaken the perpendicular-to-jet conclusion.
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

2 major / 5 minor

Summary. The paper presents VLT/FORS2 spectropolarimetry of the nucleus of the low-luminosity radio galaxy 3C 270 (NGC 4261). After subtracting the interstellar polarization estimated from the nearby star HD 107289, the authors find that the optical continuum and the Hα and [S II] line complexes are polarized at position angles nearly perpendicular to the radio jet, consistent with polar scattering. They show that the polarized line profiles can be modeled by the narrow-line profiles from the total-flux spectrum, and they use an injection test in which 37 type-I AGN broad Hα profiles are scaled onto the polarized continuum; fewer than 6% (2/37) would remain undetected at their SNR threshold. On this basis they argue that 3C 270 contains no hidden broad-line region or big blue bump, and that the scattered continuum is dominated by RIAF and/or beamed synchrotron emission. A caveat is stated at the end: because the scattered continuum is only weakly detected, a commensurate BBB and BLR cannot be totally ruled out.

Significance. If the no-hidden-BLR conclusion holds, this is a valuable empirical data point for low-luminosity AGN accretion models, joining NGC 4258 and Centaurus A as a candidate scattered-only NLR object. The polarimetric calibration is carefully cross-checked with standard stars and with Capetti et al. (2007), and the injection-test methodology is a sensible way to avoid arbitrary assumptions about the shape of an undetected line. The perpendicular polarization of both continuum and narrow lines is robust and makes a strong case for polar scattering geometry. The paper is clearly written and the data appear of good quality.

major comments (2)
  1. [Sec. 3.2, Table A1, Fig. A1] The conclusion that no hidden BLR/BBB is present rests almost entirely on the statement that fewer than 6% (2/37) of the injected type-I profiles would remain undetected. This statistic is conditional on the explicitly stated assumption that the 37 luminous quasars are representative of all classified type-I AGNs, and that assumption is not tested. Two of the 37 templates are themselves not confidently detected, as shown in Fig. A1 for PG 1004+130. Because the templates are scaled by their own quasar equivalent widths, the test has no demonstrated sensitivity to a hidden BLR with a lower equivalent width (for example, narrow-line Seyfert 1s or low-luminosity Seyferts) or with a strongly asymmetric or double-peaked profile. I request an explicit completeness study over EW, FWHM, and profile shape, and a correspondingly qualified statement in the abstract and in Section 3.2, so that the quoted '94%' is not presented as a general upper limit on the detectability of any hidden BLR.
  2. [Sec. 3.2, detection criterion] The detection criterion is defined as SNR > 3 at the wavelength corresponding to the half-maximum of the injected profile. This single-point metric may be insensitive to a broad, low-surface-brightness wing whose half-maximum point lies far from the line center, and it is not an integrated significance. I ask the authors either to use an integrated or matched-filter detection statistic, or to demonstrate explicitly that the single-point criterion gives the same completeness for broad profiles (e.g., FWHM ≳ 8000 km/s). This point is directly load-bearing for the no-BLR claim, since the two undetected templates in Fig. A1 already show that the criterion is not universally sensitive.
minor comments (5)
  1. [Sec. 2.1] The ISP correction assumes λmax = 5500 Å for HD 107289 without a stated justification or an uncertainty estimate. The line polarization angles are nearly unaffected by this choice, so the scattering geometry is robust, but the continuum polarization degree and the polarized continuum flux used in Section 3.2 could shift; please add a brief sensitivity test or a literature-based justification for the assumed λmax.
  2. [Abstract and Sec. 4] The abstract's wording that 3C 270 is 'the third known case ... with no evidence of an underlying Big Blue Bump' is stronger than the caveat in Section 4 that 'a commensurate BBB and BLR can't be totally ruled out.' These statements are not strictly contradictory, but the abstract should carry the same caveat, especially given the representativeness limitation of the injection-test sample.
  3. [Sec. 2] The date '2024 / 01 / 24' in the calibration paragraph should read '2014 / 01 / 24', consistent with the observation dates given earlier in the section.
  4. [Sec. 3.2 and Table A1] The sentence 'Over 94% of a sample of Seyfert I broad line profile would be significantly detected' has a grammar issue; it should read 'broad-line profiles' or similar.
  5. [Sec. 3.1] The reduced chi-square value of 1.6 for the narrow-line-only fit is reported without the fitted wavelength range or the number of degrees of freedom; adding these details would make the fit assessment more transparent.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the no-hidden-BLR/BBB inference rests on an external template injection test with a fixed SNR threshold, not on fitted or self-referential inputs.

full rationale

The paper's central inference is that the polarized flux spectrum of 3C 270 requires no broad-line component and that no hidden BBB/BLR is present. This rests on two independent pieces of evidence. First, the Stokes flux line profiles are acceptably fit using only the narrow-line profiles extracted from the total flux spectrum, with no broad component required (Section 3.1, Fig. 4). Second, the injection test in Section 3.2 takes 37 real type-I quasar H-alpha profiles from external sources (Schmidt & Green 1983; Stirpe 1990; SDSS), scales them by their own equivalent widths, injects them into the measured polarized-flux noise, and applies a predefined SNR > 3 detection threshold; 35 of 37 would be detected. The two undetected profiles, including PG 1004+130 shown in Fig. A1, come from the external Schmidt & Green sample, so the quoted 94% statistic is not manufactured by the authors' own data. The ISP correction uses an independent proxy star, HD 107289, with a 3D dust-map check and agreement with Capetti et al. (2007), so no fitted parameter is renamed as a prediction. The self-citations present (Marin et al. 2025 for the injection method; Jiang et al. in prep. for 9 SDSS templates) are not load-bearing: the method is fully described in this paper, the templates are public spectra, and the conclusion does not depend on any unpublished claim. The Discussion explicitly caveats that 'a commensurate BBB and BLR can't be totally ruled out' because the scattered continuum is only weakly detected, which is an honest limitation rather than a circular move. The sample-representativeness assumption is a legitimate robustness concern about external validity, not a circularity in the derivation chain. Overall, the derivation is self-contained against external benchmarks and no claim reduces by construction to its own inputs.

Assumptions & free parameters 2 free parameters · 5 assumptions · 0 invented entities

The central claim depends on the ISP proxy-star assumption, the representativeness of the type-I sample, and the BBB-BLR association. No new physical entities or fitted parameters are introduced to force the conclusion, but the assumed lambda_max and the chosen detection threshold are free choices that influence the quantitative limits.

free parameters (2)
  • Serkowski lambda_max of interstellar polarization = 5500 Angstrom (assumed)
    The peak wavelength of the Serkowski ISP law is set to 5500 A rather than measured for the line of sight; a different value would change the ISP spectral shape and the corrected continuum at red and blue wavelengths, though the line polarization angles are less sensitive.
  • Broad-line detection threshold = SNR = 3
    In Section 3.2, a broad feature is considered detected only if the signal-to-noise ratio at its half-maximum wavelength exceeds 3; changing this threshold changes the quoted fraction of detectable type-I profiles.
assumptions (5)
  • domain assumption The interstellar polarization toward 3C 270 can be represented by the polarization of the star HD 107289, located 12 arcminutes away, with polarization angle coherent to within 10 degrees over 5-degree scales.
    Invoked in Section 2.1 to construct the q_ISP and u_ISP corrections; if the line-of-sight dust differs from this proxy, the corrected polarization angles shift.
  • domain assumption The Serkowski relation with lambda_max = 5500 A describes the wavelength dependence of the interstellar polarization.
    Used in Section 2.1 to extrapolate the ISP from the star's R-band measurement to the full optical spectrum.
  • domain assumption The 37-spectrum sample of luminous quasars is representative of all classified type-I AGN broad-line profiles.
    Stated explicitly in Section 3.2; the no-BLR conclusion depends directly on this assumption.
  • domain assumption A hidden standard accretion disk (the big blue bump) would be accompanied by a broad-line region whose lines scatter into our line of sight.
    The standard unification assumption used to convert the non-detection of broad lines into the absence of a BBB.
  • ad hoc to paper The total-flux narrow-line profiles can model the scattered Stokes flux profiles with only a normalization change.
    Acknowledged in Section 3.1 as a simplification that may be non-unique when the scattering mirror size is comparable to the NLR size.

how reviews work

0 comments
Cite this review

Pith. "Pith review of The central engine of low-luminosity radio galaxy 3C 270 (NGC 4261)." pith.science (2026). https://pith.science/paper/ZFVXYJNO

@misc{pith2026241210591,
  author       = {Pith},
  title        = {Pith review of: The central engine of low-luminosity radio galaxy 3C 270 (NGC 4261)},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/ZFVXYJNO}},
  note         = {Machine review of arXiv:2412.10591}
}
read the original abstract

We present the polarization spectra of the nucleus of 3C~270. We confirm that the polarization angle of both the continuum and the emission lines are close to perpendicular to the jet direction after careful correction of interstellar polarization, which indicates polar scattering. The Stokes flux spectrum resembles the total flux spectrum, with no need for a broad component from the Broad Line Region. Over 94\% of a sample of Seyfert I broad line profile would be significantly detected if present in our polarized flux spectrum. We favor the hypothesis that we are observing the continuum including any contribution from Radiatively Inefficient Accretion Flow and beamed synchrotron instead of a Big Blue Bump, as well as the innermost Narrow Line Region, through reflection. This makes 3C~270 the third known case, after NGC~4258 and Centaurus~A, where only narrow lines (and the continuum, if present) are scattered, with no evidence of an underlying Big Blue Bump.

Figures

Figures reproduced from arXiv: 2412.10591 by the authors.

Figure 1
Figure 1. The figure displays the total flux spectrum along with the unnormalized Stokes Q and U spectra before interstellar polarization correction. All three spectra have the same units (×10−16 erg cm−2 s −1 ˚A −1 ). The linear polarization degree P and polarization an￾gle PA are derived from q and u using the standard relations: P = p q 2 + u 2 (3) PA = 1 2 arctan  u q  . (4) For calibration, we selected a zero-polarizat… view at source ↗
Figure 2
Figure 2. 3. RESULTS The radio jet position angle is measured 88◦ ± 1 ◦ at 4.885 GHz (Birkinshaw & Davies 1985). After correct￾ing for the ISP, we find that the polarization angle of the continuum is close to perpendicular to the jet direction, [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. The upper panel presents the polarization angle as a function of wavelength. Black points indicate the continuum polarization. The red cross represents the integrated polarization of the Hα complex after continuum subtraction and the red dot denotes the integrated polarization of the [S II] complex, also following continuum subtraction. The black dotted line marks the position angle perpendicular to the jet axis. Th… view at source ↗
Figures from the paper (1 more)
Figure 4
Figure 4. Figure 4: The upper panel shows modeling the polarized line profile (in black) with the profile from the total flux spectrum (in blue). The lower panel shows the residuals from the fitting. sion from the BLR. We acknowledge that the profile in the Stokes flux and total flux may …

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

47 extracted references · 13 canonical work pages

  1. [1]

    2012, Astronomical and Astrophysical Transactions, 27, 557, doi: 10.48550/arXiv.1210.2716

    Antonucci, R. 2012, Astronomical and Astrophysical Transactions, 27, 557, doi: 10.48550/arXiv.1210.2716

    arXiv doi:10.48550/arxiv.1210.2716 2012

  2. [2]

    Antonucci, R. R. J. 1984, ApJ, 278, 499, doi: 10.1086/161816

    doi:10.1086/161816 1984

  3. [3]

    F., & Duschl, W

    Asmus, D., Gandhi, P., Smette, A., H¨ onig, S. F., & Duschl, W. J. 2011, A&A, 536, A36, doi: 10.1051/0004-6361/201116693

    doi:10.1051/0004-6361/201116693 2011

  4. [4]

    F., Gandhi, P., Smette, A., & Duschl, W

    Asmus, D., H¨ onig, S. F., Gandhi, P., Smette, A., & Duschl, W. J. 2014, MNRAS, 439, 1648, doi: 10.1093/mnras/stu041 Astropy Collaboration, Robitaille, T. P., Tollerud, E. J., et al. 2013, A&A, 558, A33, doi: 10.1051/0004-6361/201322068 Astropy Collaboration, Price-Whelan, A. M., Sip˝ ocz, B. M., et al. 2018, AJ, 156, 123, doi: 10.3847/1538-3881/aabc4f

    doi:10.1093/mnras/stu041 2014

  5. [5]

    2006, A&A, 451, 35, doi: 10.1051/0004-6361:20053799

    Balmaverde, B., Capetti, A., & Grandi, P. 2006, A&A, 451, 35, doi: 10.1051/0004-6361:20053799

    work page doi:10.1051/0004-6361:20053799 2006

  6. [6]

    J., Filippenko, A

    Barth, A. J., Filippenko, A. V., & Moran, E. C. 1999a, ApJ, 525, 673, doi: 10.1086/307941 —. 1999b, ApJL, 515, L61, doi: 10.1086/311976

    doi:10.1086/307941

  7. [7]

    J., Tran, H

    Barth, A. J., Tran, H. D., Brotherton, M. S., et al. 1999c, AJ, 118, 1609, doi: 10.1086/301055

    doi:10.1086/301055

  8. [8]

    2014, A&A, 561, A24, doi: 10.1051/0004-6361/201322604

    Berdyugin, A., Piirola, V., & Teerikorpi, P. 2014, A&A, 561, A24, doi: 10.1051/0004-6361/201322604

    doi:10.1051/0004-6361/201322604 2014

Show all 47 references
  1. [9]

    2022, MNRAS, 516, 5775, doi: 10.1093/mnras/stac2290

    Bianchi, S., Chiaberge, M., Laor, A., et al. 2022, MNRAS, 516, 5775, doi: 10.1093/mnras/stac2290

    2022 doi

  2. [10]

    2019, MNRAS, 488, L1, doi: 10.1093/mnrasl/slz080

    Bianchi, S., Antonucci, R., Capetti, A., et al. 2019, MNRAS, 488, L1, doi: 10.1093/mnrasl/slz080

    2019 doi

  3. [11]

    Birkinshaw, M., & Davies, R. L. 1985, ApJ, 291, 32, doi: 10.1086/163038

    1985 doi

  4. [12]

    D., Walsh, J

    Boizelle, B. D., Walsh, J. L., Barth, A. J., et al. 2021, ApJ, 908, 19, doi: 10.3847/1538-4357/abd24d

    2021 doi

  5. [13]

    J., Chiaberge, M., et al

    Capetti, A., Axon, D. J., Chiaberge, M., et al. 2007, A&A, 471, 137, doi: 10.1051/0004-6361:20077370

    2007 doi

  6. [14]

    2000, MNRAS, 318, 493, doi: 10.1046/j.1365-8711.2000.03823.x

    Chiaberge, M. 2000, MNRAS, 318, 493, doi: 10.1046/j.1365-8711.2000.03823.x

    2000

  7. [15]

    1999, A&A, 349, 77, doi: 10.48550/arXiv.astro-ph/9907064

    Chiaberge, M., Capetti, A., & Celotti, A. 1999, A&A, 349, 77, doi: 10.48550/arXiv.astro-ph/9907064

    1999 doi arXiv

  8. [16]

    D., Sparks, W

    Chiaberge, M., Gilli, R., Macchetto, F. D., Sparks, W. B., & Capetti, A. 2003, ApJ, 582, 645, doi: 10.1086/344690 de Menezes, R., Nemmen, R., Finke, J. D., Almeida, I., &

    2003 doi

  9. [17]

    2020, MNRAS, 492, 4120, doi: 10.1093/mnras/staa083

    Rani, B. 2020, MNRAS, 492, 4120, doi: 10.1093/mnras/staa083

    2020 doi

  10. [18]

    2008, NewAR, 52, 274, doi: 10.1016/j.newar.2008.06.010

    Elitzur, M. 2008, NewAR, 52, 274, doi: 10.1016/j.newar.2008.06.010

    2008 doi

  11. [19]

    Elitzur, M., & Ho, L. C. 2009, ApJL, 701, L91, doi: 10.1088/0004-637X/701/2/L91

    2009 doi

  12. [20]

    A., McClintock, J

    Esin, A. A., McClintock, J. E., & Narayan, R. 1997, ApJ, 489, 865, doi: 10.1086/304829

    1997 doi

  13. [21]

    C., & Jaffe, W

    Ferrarese, L., Ford, H. C., & Jaffe, W. 1996, ApJ, 470, 444, doi: 10.1086/177876 10 Gonz´ alez-Mart ´ ın, O., Masegosa, J., Hern´ an-Caballero, A., et al. 2017, ApJ, 841, 37, doi: 10.3847/1538-4357/aa6f16

    1996 doi

  14. [22]

    2019, ApJ, 887, 93, doi: 10.3847/1538-4357/ab5362

    Finkbeiner, D. 2019, ApJ, 887, 93, doi: 10.3847/1538-4357/ab5362

    2019 doi

  15. [23]

    2000, AJ, 119, 923, doi: 10.1086/301236

    Heiles, C. 2000, AJ, 119, 923, doi: 10.1086/301236

    2000 doi

  16. [24]

    Ho, L. C. 1999, ApJ, 516, 672, doi: 10.1086/307137

    1999 doi

  17. [25]

    C., Filippenko, A

    Ho, L. C., Filippenko, A. V., & Sargent, W. L. 1995, ApJS, 98, 477, doi: 10.1086/192170 H¨ onig, S. F., & Beckert, T. 2007, MNRAS, 380, 1172, doi: 10.1111/j.1365-2966.2007.12157.x

    1995

  18. [26]

    Jaffe, W., Ford, H., Ferrarese, L., van den Bosch, F., & O’Connell, R. W. 1996, ApJ, 460, 214, doi: 10.1086/176963

    1996 doi

  19. [27]

    C., Ferrarese, L., van den Bosch, F., & O’Connell, R

    Jaffe, W., Ford, H. C., Ferrarese, L., van den Bosch, F., & O’Connell, R. W. 1993, Nature, 364, 213, doi: 10.1038/364213a0

    1993 doi

  20. [28]

    M., Tremonti, C., et al

    Kauffmann, G., Heckman, T. M., Tremonti, C., et al. 2003, MNRAS, 346, 1055, doi: 10.1111/j.1365-2966.2003.07154.x

    2003

  21. [29]

    J., Groves, B., Kauffmann, G., & Heckman, T

    Kewley, L. J., Groves, B., Kauffmann, G., & Heckman, T. 2006, MNRAS, 372, 961, doi: 10.1111/j.1365-2966.2006.10859.x

    2006

  22. [30]

    2009, ApJ, 701, 891, doi: 10.1088/0004-637X/701/2/891

    Leipski, C., Antonucci, R., Ogle, P., & Whysong, D. 2009, ApJ, 701, 891, doi: 10.1088/0004-637X/701/2/891

    2009 doi

  23. [31]

    2018, MNRAS, 479, 3142, doi: 10.1093/mnras/sty1566

    Marin, F. 2018, MNRAS, 479, 3142, doi: 10.1093/mnras/sty1566

    2018 doi

  24. [32]

    Z., et al

    Marin, F., Hutsem´ ekers, D., Jiang, C. Z., et al. 2025, arXiv e-prints, arXiv:2502.05002, doi: 10.48550/arXiv.2502.05002 Mart ´ ınez Gonz´ alez, M. J., Asensio Ramos, A., Manso

    2025 doi arXiv

  25. [33]

    Sainz, R., Corradi, R. L. M., & Leone, F. 2015, A&A, 574, A16, doi: 10.1051/0004-6361/201424245

    2015 doi

  26. [34]

    2006, ApJ, 647, 161, doi: 10.1086/505337

    Ogle, P., Whysong, D., & Antonucci, R. 2006, ApJ, 647, 161, doi: 10.1086/505337

    2006 doi

  27. [35]

    M., Cohen, M

    Ogle, P. M., Cohen, M. H., Miller, J. S., et al. 1997, ApJL, 482, L37, doi: 10.1086/310675 Ramos Almeida, C., Mart ´ ınez Gonz´ alez, M. J., Asensio

    1997 doi

  28. [36]

    2016, MNRAS, 461, 1387, doi: 10.1093/mnras/stw1388

    Ramos, A., et al. 2016, MNRAS, 461, 1387, doi: 10.1093/mnras/stw1388

    2016 doi

  29. [37]

    A., Cappellari, M., et al

    Ruffa, I., Davis, T. A., Cappellari, M., et al. 2023, MNRAS, 522, 6170, doi: 10.1093/mnras/stad1119

    2023 doi

  30. [38]

    Schmidt, M., & Green, R. F. 1983, ApJ, 269, 352, doi: 10.1086/161048

    1983 doi

  31. [39]

    S., & Ford, V

    Serkowski, K., Mathewson, D. S., & Ford, V. L. 1975, ApJ, 196, 261, doi: 10.1086/153410

    1975 doi

  32. [40]

    T., Strauss, M

    Shen, Y., Richards, G. T., Strauss, M. A., et al. 2011, ApJS, 194, 45, doi: 10.1088/0067-0049/194/2/45

    2011 doi

  33. [41]

    Stirpe, G. M. 1990, A&AS, 85, 1049

    1990

  34. [42]

    2003, A&A, 403, 889, doi: 10.1051/0004-6361:20030417

    Feretti, L. 2003, A&A, 403, 889, doi: 10.1051/0004-6361:20030417

    2003 doi

  35. [43]

    P., Baum, S

    Vaddi, S., O’Dea, C. P., Baum, S. A., et al. 2016, ApJ, 818, 182, doi: 10.3847/0004-637X/818/2/182

    2016 doi

  36. [44]

    A., Morganti, R., Tadhunter, C

    Wills, K. A., Morganti, R., Tadhunter, C. N., Robinson, T. G., & Villar-Martin, M. 2004, MNRAS, 347, 771, doi: 10.1111/j.1365-2966.2004.07195.x

    2004

  37. [45]

    M., Birkinshaw, M., O’Sullivan, E., et al

    Worrall, D. M., Birkinshaw, M., O’Sullivan, E., et al. 2010, MNRAS, 408, 701, doi: 10.1111/j.1365-2966.2010.17162.x

    2010

  38. [46]

    1994, ApJS, 95, 107, doi: 10.1086/192096

    Worthey, G. 1994, ApJS, 95, 107, doi: 10.1086/192096

    1994 doi

  39. [47]

    2005, ApJ, 627, 711, doi: 10.1086/430044

    Fabbiano, G. 2005, ApJ, 627, 711, doi: 10.1086/430044

    2005 doi

Pith tools

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