pith. sign in

arxiv: 2605.19472 · v1 · pith:4KIZF27Unew · submitted 2026-05-19 · 🌌 astro-ph.SR

Chromospheric resonator model for sunspot revealed by multi-height observation of umbral wave

Pith reviewed 2026-05-20 02:50 UTC · model grok-4.3

classification 🌌 astro-ph.SR
keywords sunspot oscillationsumbral waveschromospheric resonatorslow magnetoacoustic wavessunspot seismologyH-alpha observationsphase analysis
0
0 comments X

The pith

Phase patterns in Hα observations indicate umbral waves are confined in a non-ideal acoustic resonator.

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

The paper uses high-resolution multi-wavelength data from the Goode Solar Telescope to track oscillations in a sunspot's chromosphere. Spectral analysis detects roughly three-minute signals in both the core and wings of the Hα line. Cross-wavelet phase analysis between wing-integrated intensity, line-core intensity, and Doppler velocity reveals a mix of standing waves and upward-propagating slow magnetoacoustic modes. These patterns lead the authors to conclude that the waves are trapped inside a non-ideal acoustic resonator, supplying measurable properties that can feed into sunspot seismology and help refine models of sunspot atmospheric structure.

Core claim

The observed phase relationships demonstrate that umbral waves consist of slow magnetoacoustic modes manifesting as standing waves confined within a non-ideal acoustic resonator, accompanied by upward propagating components.

What carries the argument

Cross-wavelet analysis of phase lags between Hα wing-integrated intensity, line-core intensity, and centroid-derived Doppler velocity at multiple formation heights.

If this is right

  • Measurable wave properties extracted from the resonator can serve directly as input for sunspot seismology.
  • Refined models of sunspot atmospheric structure become possible once the resonator boundaries and damping are constrained.
  • The relative contributions of these waves to local plasma heating and mass flows can be quantified more precisely.

Where Pith is reading between the lines

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

  • The same phase-analysis method could be applied to other magnetically structured regions to test whether resonator behavior is common.
  • Higher-cadence or multi-line data might separate true resonator effects from height-dependent line-formation artifacts.
  • If the resonator model holds, it supplies a new route to estimate the vertical extent and magnetic-field strength profile inside sunspots.

Load-bearing premise

The measured phase lags between Hα wing-integrated intensity, line-core intensity, and Doppler velocity uniquely identify a standing-wave resonator rather than other wave geometries or line-formation effects.

What would settle it

Independent multi-height observations in the same or additional spectral lines that yield phase differences inconsistent with the expected standing-wave pattern in a non-ideal resonator would falsify the claim.

Figures

Figures reproduced from arXiv: 2605.19472 by A.K. Srivastava, Ding Yuan, Kartika Sangal, Libo Fu, Song Feng, Yuandeng Shen.

Figure 1
Figure 1. Figure 1: Multi-instrument observations of the active region. (a) Full-disk solar image from AIA/SDO in the 171 Å filter. The red box indicates the region of interest. On the top right of the panel, zoomed in view of the red box is shown,and within which a smaller black box is overplotted, marking the GST field of view. (b-f) Zoomed in view of the selected region in the H blue wings. (g) Zoomed in view in the H line… view at source ↗
Figure 2
Figure 2. Figure 2: Temporal evolution and spectral analysis of H signals. (a1) Intensity of H-0.2 Å; (b1) Intensity of the H line core; (c1) Intensity of H+0.6 Å; (d1) Doppler velocity of the H line. All signals are extracted from a pixel at (x = 119′′, y = 159′′); (a2–d2) FFT power (black), global wavelet power (red), power-law fit (green), and 95% local significance level (blue) for the respective time-series; (a3–d3) Wave… view at source ↗
Figure 3
Figure 3. Figure 3: Cross-wavelet analysis between intensity of different H passbands and Doppler velocity (center-of-mass) of H line. (a1) Wing integrating intensity time-series for H± 1.0 Å (black) and Doppler velocity (red); (b1) Wing integrating intensity time-series for H± 0.6 Å (black) and Doppler velocity (red); (c1) Wing integrating intensity time-series for H± 0.2 Å (black) and Doppler velocity (red); (d1) Intensity … view at source ↗
Figure 4
Figure 4. Figure 4: (a–e) Histograms of significant phase differences between H intensity (averaged from both line wings) and Doppler velocity (derived from line center-of-mass) time-series at selected umbral locations. (f) Histogram of significant phase differences between H line-core intensity and Doppler velocity (derived from line center-of-mass) time-series at the same locations. The peak phase difference are menioned in… view at source ↗
Figure 5
Figure 5. Figure 5: Histogram of phase differences between intensity signals from different combinations of H passbands in the 3 min band. The specific passband pairs are indicated at the top of each panel. The red curves represent Gaussian fits to the distributions, and the corresponding peak phase values are indicated in each panel. The phase differences are predominantly clustered around 0°, with small deviations (within ±… view at source ↗
read the original abstract

Sunspots are transient, magnetically intense features that host oscillations linked to magnetohydrodynamic (MHD) waves. These waves may contribute to plasma heating and drive mass flows in the solar wind. Beyond their energetic role, they serve as diagnostic tools for probing sunspot structure. In this study, we investigated chromospheric wave propagation in a sunspot using high-resolution, multi-wavelength observations from the Goode Solar Telescope at Big Bear Solar Observatory. Spectral analysis shows that the intensity at H$\alpha$ line core and its wings exhibited oscillatory signal at about 3 min. We performed a cross-wavelet analysis to examine the phase relationship between the wing-integrated and line-core intensity oscillations of the H$\alpha$ line and the centroid-derived H$\alpha$ Doppler velocity. We also analyze the phase relationships between intensity pairs from different passband combinations of the H$\alpha$ line. The results indicate the presence of slow magnetoacoustic modes manifesting standing waves along with upward propagating waves. The observed phase patterns suggest that umbral waves are confined within a non-ideal acoustic resonator, providing measurable wave properties that could serve as input for sunspot seismology and refine models of sunspot atmospheric structure.

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

1 major / 2 minor

Summary. The manuscript reports high-resolution, multi-wavelength observations of umbral oscillations in a sunspot using the Hα line from the Goode Solar Telescope. Spectral analysis identifies ~3-minute oscillatory signals in the line-core and wing intensities. Cross-wavelet analysis is applied to quantify phase relationships between wing-integrated intensity, line-core intensity, and centroid-derived Doppler velocity, as well as between different Hα passband combinations. The authors interpret the resulting phase patterns as evidence for slow magnetoacoustic modes that combine standing waves with upward-propagating components, concluding that the waves are confined within a non-ideal acoustic resonator and that the measured properties can serve as inputs for sunspot seismology.

Significance. If the central interpretation is robust, the work supplies direct observational constraints on wave propagation and confinement across chromospheric heights in sunspots. Such constraints could refine atmospheric models and enable seismological diagnostics of sunspot structure. The multi-height approach using a single spectral line is a methodological strength.

major comments (1)
  1. [Cross-wavelet analysis] Cross-wavelet analysis: the observed phase lags (reported as ~90° or 180° with height dependence) are presented as diagnostic of standing slow magnetoacoustic modes inside a non-ideal acoustic resonator. However, the manuscript contains no quantitative forward modeling or synthesis of observables from alternative scenarios (e.g., upward-propagating waves whose amplitude or phase speed varies with height, or differential formation-height effects within the Hα profile). Without such tests, the data are shown to be compatible with the resonator model but not demonstrated to require it, which directly affects the load-bearing claim that the phase patterns “suggest” confinement.
minor comments (2)
  1. [Abstract] The abstract and results sections would benefit from explicit numerical reporting of the measured phase differences together with their uncertainties and coherence thresholds from the wavelet analysis.
  2. [Observations and data analysis] Details on the precise wavelength integration windows for the “wing-integrated intensity,” the method used to derive the centroid velocity, and any spatial or temporal averaging applied to the time series should be added for reproducibility.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their constructive and detailed review of our manuscript. We address the single major comment below and describe the revisions we intend to implement to strengthen the presentation of our results.

read point-by-point responses
  1. Referee: [Cross-wavelet analysis] Cross-wavelet analysis: the observed phase lags (reported as ~90° or 180° with height dependence) are presented as diagnostic of standing slow magnetoacoustic modes inside a non-ideal acoustic resonator. However, the manuscript contains no quantitative forward modeling or synthesis of observables from alternative scenarios (e.g., upward-propagating waves whose amplitude or phase speed varies with height, or differential formation-height effects within the Hα profile). Without such tests, the data are shown to be compatible with the resonator model but not demonstrated to require it, which directly affects the load-bearing claim that the phase patterns “suggest” confinement.

    Authors: We agree that quantitative forward modeling of alternative scenarios would provide a stronger test of our interpretation. At the same time, the specific phase relations we measure—approximately 90° between intensity and Doppler velocity, together with the height-dependent phase shifts across multiple Hα passband combinations—are the expected signatures of a superposition of standing and upward-propagating slow magnetoacoustic waves inside a chromospheric resonator. A purely propagating wave whose amplitude or phase speed changes with height would produce a more monotonic phase progression with height, which is not seen in the cross-wavelet spectra. Our use of several passband pairs within the same spectral line already reduces the impact of differential formation-height effects. We will revise the discussion section to (i) explicitly compare the observed phase patterns against the expectations for the alternative scenarios raised by the referee and (ii) qualify our conclusions as suggestive rather than definitive, thereby clarifying the evidential weight of the current data. revision: yes

Circularity Check

0 steps flagged

No circularity: purely observational phase analysis

full rationale

The paper reports multi-height Hα observations from the Goode Solar Telescope and applies cross-wavelet analysis to measured intensity and Doppler signals. The resonator interpretation is drawn directly from the observed phase lags (~90° or 180°) and their height dependence without any fitted parameters, self-referential equations, or load-bearing self-citations that reduce the central claim to its own inputs. No derivation chain exists that equates a prediction to a prior fit or imported ansatz; the conclusions remain an empirical inference from the reported data patterns.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 1 invented entities

The central claim rests on standard MHD wave propagation in stratified atmospheres and the assumption that Hα intensity and Doppler signals faithfully trace acoustic wave phases at different formation heights.

axioms (1)
  • domain assumption Slow magnetoacoustic waves propagate vertically in sunspot umbrae with observable intensity and velocity signatures at Hα formation heights.
    Invoked when interpreting the 3-min oscillations and phase lags as slow modes.
invented entities (1)
  • non-ideal acoustic resonator no independent evidence
    purpose: To explain the coexistence of standing and upward-propagating waves via partial reflection or trapping.
    Introduced to account for the observed phase patterns; no independent falsifiable prediction (e.g., specific resonance frequencies) is given in the abstract.

pith-pipeline@v0.9.0 · 5755 in / 1300 out tokens · 33637 ms · 2026-05-20T02:50:53.513867+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.

  • IndisputableMonolith/Foundation/AlexanderDuality.lean alexander_duality_circle_linking unclear
    ?
    unclear

    Relation between the paper passage and the cited Recognition theorem.

    The observed phase patterns suggest that umbral waves are confined within a non-ideal acoustic resonator... phase relationships between intensity pairs from different passband combinations of the Hα line... slow magnetoacoustic modes manifesting standing waves along with upward propagating waves.

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

101 extracted references · 101 canonical work pages

  1. [1]

    E., Lites, B

    Abdelatif, T. E., Lites, B. W., & Thomas, J. H.\ 1986, , 311, 1015. doi:10.1086/164838

  2. [2]

    Anderson, L. S. & Athay, R. G.\ 1989, , 346, 1010. doi:10.1086/168083

  3. [3]

    doi:10.3847/0004-637X/825/2/110

    Auch \`e re, F., Froment, C., Bocchialini, K., et al.\ 2016, , 825, 2, 110. doi:10.3847/0004-637X/825/2/110

  4. [4]

    Beckers, J. M. & Tallant, P. E.\ 1969, , 7, 351. doi:10.1007/BF00146140

  5. [5]

    Beckers, J. M. & Schultz, R. B.\ 1972, , 27, 61. doi:10.1007/BF00151770

  6. [6]

    R., Collados, M., Ruiz Cobo, B., et al.\ 2000, , 534, 989

    Bellot Rubio, L. R., Collados, M., Ruiz Cobo, B., et al.\ 2000, , 534, 989. doi:10.1086/308791

  7. [7]

    J.\ 2000, , 192, 373

    Bogdan, T. J.\ 2000, , 192, 373. doi:10.1023/A:1005225214520

  8. [8]

    Bogdan, T. J. & Judge, P. G.\ 2006, Philosophical Transactions of the Royal Society of London Series A, 364, 313. doi:10.1098/rsta.2005.1701

  9. [9]

    Botha, G. J. J., Arber, T. D., Nakariakov, V. M., et al.\ 2011, , 728, 84. doi:10.1088/0004-637X/728/2/84

  10. [10]

    doi:10.1002/asna.201011390

    Cao, W., Gorceix, N., Coulter, R., et al.\ 2010, Astronomische Nachrichten, Scientific instrumentation for the 1.6 m New Solar Telescope in Big Bear, 331, 6, 636. doi:10.1002/asna.201011390

  11. [11]

    doi:10.1086/500185

    Centeno, R., Collados, M., & Trujillo Bueno, J.\ 2006, , 640, 1153. doi:10.1086/500185

  12. [12]

    doi:10.3847/1538-4357/836/1/18

    Chae, J., Lee, J., Cho, K., et al.\ 2017, , 836, 18. doi:10.3847/1538-4357/836/1/18

  13. [13]

    E.\ 2019, , 883, 72

    Chae, J., Kang, J., & Litvinenko, Y. E.\ 2019, , 883, 72. doi:10.3847/1538-4357/ab3d2d

  14. [14]

    E., Reardon, K

    Chai, Y., Gary, D. E., Reardon, K. P., et al.\ 2022, , 924, 2, 100. doi:10.3847/1538-4357/ac34f7

  15. [15]

    B., Georgakilas, A

    Christopoulou, E. B., Georgakilas, A. A., & Koutchmy, S.\ 2000, , 354, 305

  16. [16]

    M., et al.\ 2015, , 802, 45

    Cho, K.-S., Bong, S.-C., Nakariakov, V. M., et al.\ 2015, , 802, 45. doi:10.1088/0004-637X/802/1/45

  17. [17]

    IV - Evanescent waves of small amplitude, 236, 2, 509

    Deubner, F.-L., Fleck, B., Marmolino, C., et al.\ 1990, , Dynamics of the solar atmosphere. IV - Evanescent waves of small amplitude, 236, 2, 509

  18. [18]

    doi:10.1088/0004-637X/722/1/131

    Felipe, T., Khomenko, E., Collados, M., et al.\ 2010, , 722, 131. doi:10.1088/0004-637X/722/1/131

  19. [19]

    doi:10.1088/0004-637X/719/1/357

    Felipe, T., Khomenko, E., & Collados, M.\ 2010, , 719, 357. doi:10.1088/0004-637X/719/1/357

  20. [20]

    J., et al.\ 2020, , 900, L29

    Felipe, T., Kuckein, C., Gonz \'a lez Manrique, S. J., et al.\ 2020, , 900, L29. doi:10.3847/2041-8213/abb1a5

  21. [21]

    doi:10.1051/0004-6361/201935784

    Felipe, T.\ 2019, , 627, A169. doi:10.1051/0004-6361/201935784

  22. [22]

    & Schmitz, F.\ 1991, , 250, 235

    Fleck, B. & Schmitz, F.\ 1991, , 250, 235

  23. [23]

    doi:10.1088/1674-4527/ac91bd

    Fu, L., Zhu, Z., Yuan, D., et al.\ 2022, Research in Astronomy and Astrophysics, Inter-correlation between Sunspot Oscillations and Their Internal Structures, 22, 11, 115009. doi:10.1088/1674-4527/ac91bd

  24. [24]

    A., Jess , D

    Gilchrist-Millar, C. A., Jess, D. B., Grant, S. D. T., et al.\ 2021, Philosophical Transactions of the Royal Society of London Series A, 379, 20200172. doi:10.1098/rsta.2020.0172

  25. [25]

    G.\ 1972, , 27, 71

    Giovanelli, R. G.\ 1972, , 27, 71. doi:10.1007/BF00151771

  26. [26]

    B.\ 1987, , 108, 61

    Gurman, J. B.\ 1987, , 108, 61. doi:10.1007/BF00152077

  27. [27]

    H., Wikst l, ., Brynildsen, N., et al.\ 2002, SOLMAG 2002

    Hansteen, V. H., Wikst l, ., Brynildsen, N., et al.\ 2002, SOLMAG 2002. Proceedings of the Magnetic Coupling of the Solar Atmosphere Euroconference, 505, 183

  28. [28]

    doi:10.3847/1538-4357/aaab5a

    Hou, Z., Huang, Z., Xia, L., et al.\ 2018, , 855, 65. doi:10.3847/1538-4357/aaab5a

  29. [29]

    B., De Moortel, I., Mathioudakis, M., et al.\ 2012, , 757, 160

    Jess, D. B., De Moortel, I., Mathioudakis, M., et al.\ 2012, , 757, 160. doi:10.1088/0004-637X/757/2/160

  30. [30]

    B., Reznikova, V

    Jess, D. B., Reznikova, V. E., Van Doorsselaere, T., et al.\ 2013, , 779, 168. doi:10.1088/0004-637X/779/2/168

  31. [31]

    B., Morton , R

    Jess, D. B., Morton, R. J., Verth, G., et al.\ 2015, , 190, 103. doi:10.1007/s11214-015-0141-3

  32. [32]

    B., Snow, B., Houston, S

    Jess, D. B., Snow, B., Houston, S. J., et al.\ 2020, Nature Astronomy, 4, 220. doi:10.1038/s41550-019-0945-2

  33. [33]

    B., Keys , P

    Jess, D. B., Keys, P. H., Stangalini, M., et al.\ 2021, Philosophical Transactions of the Royal Society of London Series A, 379, 20200169. doi:10.1098/rsta.2020.0169

  34. [34]

    B., Jafarzadeh , S., Keys , P

    Jess, D. B., Jafarzadeh, S., Keys, P. H., et al.\ 2023, Living Reviews in Solar Physics, 20, 1. doi:10.1007/s41116-022-00035-6

  35. [35]

    doi:10.3847/0004-637X/831/1/24

    Kanoh, R., Shimizu, T., & Imada, S.\ 2016, , 831, 24. doi:10.3847/0004-637X/831/1/24

  36. [36]

    K., Tiwari, S

    Kayshap, P., Srivastava, A. K., Tiwari, S. K., et al.\ 2020, , 634, A63. doi:10.1051/0004-6361/201936070

  37. [37]

    doi:10.1088/0004-637X/721/1/744

    Kitagawa, N., Yokoyama, T., Imada, S., et al.\ 2010, , 721, 744. doi:10.1088/0004-637X/721/1/744

  38. [38]

    & Calvo Santamaria, I.\ 2013, Journal of Physics Conference Series, 440, 012048

    Khomenko, E. & Calvo Santamaria, I.\ 2013, Journal of Physics Conference Series, 440, 012048. doi:10.1088/1742-6596/440/1/012048

  39. [39]

    & Collados, M.\ 2015, Living Reviews in Solar Physics, 12, 6

    Khomenko, E. & Collados, M.\ 2015, Living Reviews in Solar Physics, 12, 6. doi:10.1007/lrsp-2015-6

  40. [40]

    I., Kolobov, D

    Kobanov, N. I., Kolobov, D. Y., & Makarchik, D. V.\ 2006, , 238, 2, 231. doi:10.1007/s11207-006-0160-z

  41. [41]

    & Khomenko, E.\ 2013, , 559, A107

    Kostik, R. & Khomenko, E.\ 2013, , 559, A107. doi:10.1051/0004-6361/201322363

  42. [42]

    B., Van Doorsselaere, T., et al.\ 2017, , 847, 5

    Krishna Prasad, S., Jess, D. B., Van Doorsselaere, T., et al.\ 2017, , 847, 5. doi:10.3847/1538-4357/aa86b5

  43. [43]

    doi:10.1088/0004-637X/749/2/136

    Leenaarts, J., Carlsson, M., & Rouppe van der Voort, L.\ 2012, , 749, 2, 136. doi:10.1088/0004-637X/749/2/136

  44. [44]

    Leibacher, J. W. & Stein, R. F.\ 1981, NASA Special Publication, 263

  45. [45]

    W.\ 1986, , 301, 992

    Lites, B. W.\ 1986, , 301, 992. doi:10.1086/163963

  46. [46]

    W.\ 1986, , 301, 1005

    Lites, B. W.\ 1986, , 301, 1005. doi:10.1086/163964

  47. [47]

    W., White, O

    Lites, B. W., White, O. R., & Packman, D.\ 1982, , 253, 386. doi:10.1086/159642

  48. [48]

    Lites, B. W. & Thomas, J. H.\ 1985, , 294, 682. doi:10.1086/163338

  49. [49]

    W., Thomas, J

    Lites, B. W., Thomas, J. H., Bogdan, T. J., et al.\ 1998, , 497, 1, 464. doi:10.1086/305451

  50. [51]

    Locans, V., Skerse, D., Staude, J., et al.\ 1988, , 204, 263

  51. [52]

    Mariska, J. T. & Muglach, K.\ 2010, , Doppler-shift, Intensity, and Density Oscillations Observed with the Extreme Ultraviolet Imaging Spectrometer on Hinode, 713, 1, 573. doi:10.1088/0004-637X/713/1/573

  52. [53]

    A., Chae, J., Park, H., et al.\ 2013, , 288, 1, 73

    Maurya, R. A., Chae, J., Park, H., et al.\ 2013, , 288, 1, 73. doi:10.1007/s11207-013-0286-8

  53. [54]

    Moreels, M. G. & Van Doorsselaere, T.\ 2013, , Phase relations for seismology of photospheric flux tubes, 551, A137. doi:10.1051/0004-6361/201219568

  54. [55]

    J., Verth, G., Jess, D

    Morton, R. J., Verth, G., Jess, D. B., et al.\ 2012, Nature Communications, 3, 1315. doi:10.1038/ncomms2324

  55. [56]

    G., et al.\ 2007, , 59, S631

    Nagashima, K., Sekii, T., Kosovichev, A. G., et al.\ 2007, , 59, S631. doi:10.1093/pasj/59.sp3.S631

  56. [57]

    R., De Moortel, I., & Hood, A

    Owen, N. R., De Moortel, I., & Hood, A. W.\ 2009, , 494, 1, 339. doi:10.1051/0004-6361:200810828

  57. [58]

    K., & Wang, T.\ 2021, , 296, 6, 105

    Prasad, A., Srivastava, A. K., & Wang, T.\ 2021, , 296, 6, 105. doi:10.1007/s11207-021-01846-w

  58. [59]

    K., & Wang, T

    Prasad, A., Srivastava, A. K., & Wang, T. J.\ 2021, , 296, 1, 20. doi:10.1007/s11207-021-01764-x

  59. [60]

    K., Wang, T., et al.\ 2022, , 297, 1, 5

    Prasad, A., Srivastava, A. K., Wang, T., et al.\ 2022, , 297, 1, 5. doi:10.1007/s11207-021-01940-z

  60. [61]

    R., et al.\ 2022, , 666, A21

    Quintero Noda, C., Schlichenmaier, R., Bellot Rubio, L. R., et al.\ 2022, , 666, A21. doi:10.1051/0004-6361/202243867

  61. [62]

    E., Shibasaki, K., Sych, R

    Reznikova, V. E., Shibasaki, K., Sych, R. A., et al.\ 2012, , Three-minute Oscillations above Sunspot Umbra Observed with the Solar Dynamics Observatory/Atmospheric Imaging Assembly and Nobeyama Radioheliograph, 746, 2, 119. doi:10.1088/0004-637X/746/2/119

  62. [63]

    R., Warner, M., Keil, S

    Rimmele, T. R., Warner, M., Keil, S. L., et al.\ 2020, , 295, 12, 172. doi:10.1007/s11207-020-01736-7

  63. [64]

    doi:10.1098/rsta.2005.1709

    Roberts, B.\ 2006, Philosophical Transactions of the Royal Society of London Series A, 364, 447. doi:10.1098/rsta.2005.1709

  64. [65]

    P., et al.\ 2002, , 209, 265

    Sakurai, T., Ichimoto, K., Raju, K. P., et al.\ 2002, , 209, 265. doi:10.1023/A:1021297313448

  65. [66]

    K., Kayshap, P., et al.\ 2022, , 517, 458

    Sangal, K., Srivastava, A. K., Kayshap, P., et al.\ 2022, , 517, 458. doi:10.1093/mnras/stac2649

  66. [67]

    K., Kayshap, P., et al.\ 2024, , 966, 187

    Sangal, K., Srivastava, A. K., Kayshap, P., et al.\ 2024, , 966, 187. doi:10.3847/1538-4357/ad36ca

  67. [68]

    Scheuer, M. A. & Thomas, J. H.\ 1981, , 71, 21. doi:10.1007/BF00153603

  68. [69]

    Snow, B., Botha, G. J. J., & R \'e gnier, S.\ 2015, , 580, A107. doi:10.1051/0004-6361/201526115

  69. [70]

    K., Ballester, J

    Srivastava, A. K., Ballester, J. L., Cally, P. S., et al.\ 2021, Journal of Geophysical Research (Space Physics), 126, e029097. doi:10.1029/2020JA029097

  70. [71]

    B., Verth , G., Fedun , V., Fleck , B., Jafarzadeh , S., et al

    Stangalini, M., Jess, D. B., Verth, G., et al.\ 2021, , 649, A169. doi:10.1051/0004-6361/202140429

  71. [72]

    M., Karlicky, M., et al.\ 2009, , 505, 2, 791

    Sych, R., Nakariakov, V. M., Karlicky, M., et al.\ 2009, , 505, 2, 791. doi:10.1051/0004-6361/200912132

  72. [73]

    & Nakariakov, V

    Sych, R. & Nakariakov, V. M.\ 2014, , 569, A72. doi:10.1051/0004-6361/201424049

  73. [74]

    & Erd \'e lyi, R.\ 2008, , 251, 1-2, 523

    Taroyan, Y. & Erd \'e lyi, R.\ 2008, , 251, 1-2, 523. doi:10.1007/s11207-008-9154-3

  74. [75]

    K., et al.\ 2014, , 786, 137

    Tian, H., DeLuca, E., Reeves, K. K., et al.\ 2014, , 786, 137. doi:10.1088/0004-637X/786/2/137

  75. [76]

    H., Cram, L

    Thomas, J. H., Cram, L. E., & Nye, A. H.\ 1982, , 297, 485. doi:10.1038/297485a0

  76. [77]

    Thomas, J. H. & Scheuer, M. A.\ 1982, , 79, 19. doi:10.1007/BF00146970

  77. [78]

    H.\ 1985, Australian Journal of Physics, 38, 811

    Thomas, J. H.\ 1985, Australian Journal of Physics, 38, 811. doi:10.1071/PH850811

  78. [79]

    H., Lites, B

    Thomas, J. H., Lites, B. W., Gurman, J. B., et al.\ 1987, , Simultaneous Measurements of Sunspot Umbral Oscillations in the Photosphere, Chromosphere, and Transition Region, 312, 457. doi:10.1086/164890

  79. [80]

    Thomas, J. H. & Weiss, N. O.\ 1992, Sunspots. Theory and Observations, 375, 3. doi:10.1007/978-94-011-2769-1\_1

  80. [81]

    doi:10.1007/s11207-017-1191-3

    Threlfall, J., De Moortel, I., & Conlon, T.\ 2017, , 292, 165. doi:10.1007/s11207-017-1191-3

Showing first 80 references.