RADIO PHYSICS AND RADIO ASTRONOMY

Purpose: The overview of the scientifi c papers devoted to the study of the solar decameter radio emission with the world’s largest UTR-2 radio telescope (Ukraine) published for the last 50 years.

Design/methodology/approach: The study and analysis of the scientifi c papers on both sporadic and quiet (thermal) radiation of the Sun recorded with the UTR-2 radio telescope at the decameter wavelength range.

Findings: The most signifi cant observational and theoretical results of the solar radio emission studies obtained at the Institute of Radio Astronomy of the National Academy of Sciences of Ukraine for the last 50 years are given.

Conclusions: For the fi rst time, at frequencies below 30 MHz, the Type II bursts, Type IV bursts, S-bursts, drift pairs and spikes have been recorded. The dependences of these bursts parameters on frequency within the frequency band of 9 to 30 MHz were obtained. The models of their generation and propagation were suggested. Moreover, for the fi rst time the fi ne time-frequency structures of the Type III bursts, Type II bursts, Type IV bursts, U- and J-bursts, S-bursts, and drift pairs have been observed due to the high sensitivity and high time-frequency resolutions of the UTR-2 radio telescope. The super-fi ne structure of Type II bursts with a “herringbone” structure was identifi ed, which has never been observed before. New types of bursts were discovered: “caterpillar” bursts, “dog-leg” bursts, Type III bursts with decay, Type III bursts with changing drift rate sign, Type III-like bursts, Jb- and Ub-bursts, etc. An interpretation of the unusually high drift rates and drift rates with alternating signs of the Type III-like bursts was suggested. Based on the dependence of spike durations on frequency, the coronal plasma temperature profi le at the heliocentric heights of  1.5–3R_S was determined. Usage of the heliographic and interferometric methods gave the possibility to start studies of the spatial characteristics – sizes and locations of the bursts emission sources. Thus, it was shown that at the decameter band, the Type III burst durations were defi ned by the emission source linear sizes, whereas the spike durations were governed by the collision times in the source plasma. It was experimentally proved that the effective brightness temperatures of the sources of solar sporadic radio emission at the decameter band may reach values of 10¹⁴–10¹⁵ K. In addition, it was found that the radii of the quiet Sun at frequencies 20 and 25 MHz are close to the distances from the Sun at which the local plasma frequency is equal to the corresponding observed frequency of radio emission in the Baumbach–Allen model.

Key words: UTR-2; Sun; decameter radio emission; radio bursts; corona

Manuscript submitted 19.10.2020 

Radio phys. radio astron. 2021, 26(1): 074-089

REFERENCES

1. ABRANIN, E. P., BAZELYAN, L. L., RAPOPORT, V. O. and TSYBKO, YA. G., 1980. Variations of type III burst parameters during a decametric solar storm. Sol. Phys. vol. 66, is. 2, pp. 333–346. DOI: https://doi.org/10.1007/BF00150589

2. ABRANIN, É. P., BAZELYAN, L. L. and TSYBKO, YA. G., 1990. Stability of the parameters of decameter type III bursts over the 11-year solar activity cycle. Rates of frequency drift of radio burst. Sov. Astron. vol. 34, no. 1, p. 74–78.

3. ABRANIN, É. P. and BAZELYAN, L. L., 1993. Harmonic structure of decameter-wave type III emission and group delay of radio waves in the solar corona. Astron. Rep. vol. 37, is. 4, pp. 438–444.

4. ABRANIN, E. P., BAZELYAN, L. L., GONCHAROV, N. YU., ZAITSEV, V. V., ZINICHEV, V. A., RAPOPORT, V. O. and TSYBKO, YA. G., 1980. Positions of solar storm burst sources by observations with a heliograph based on the UTR-2 antenna at 25 MHz. Sol. Phys. vol. 66, is. 2, pp. 393–409. DOI: https://doi.org/10.1007/BF00150593

5. ITKINA, M. A., LEVIN, B. N. and TSYBKO, YA. G., 1993. On the radio wave group delay in the solar corona for the case of decameter type III bursts. Astron. Astrophys. vol. 279, no. 1, pp. 235–242.

6. ABRANIN, E. P., BAZELYAN, L. L., GONCHAROV, N. Yu., ZAITSEV, V. V., ZINICHEV, V. A., RAPOPORT, V. A. and TSYBKO, YA. G., 1976. Angular sizes of sources of solar radio burst in the decameter range. Sov. Astron. vol. 19, no. 5, pp. 602–605.

7. MEL’NIK, V. N., KONOVALENKO, A. A., ABRANIN, E. P., DOROVSKYY, V. V., STANISLAVSKY, A. A., RUCKER, H. O. and LECACHEUX, A., 2005. Solar sporadic radio emission in the decametre waveband. Astron. Astrophys. Trans. vol. 24, is. 5, pp. 391–401. DOI: https://doi.org/10.1080/10556790600568854

8. MEL’NIK, V. N., KONOVALENKO, A. A., RUCKER, H. O., RUTKEVYCH, B. P., DOROVSKYY, V. V., ABRANIN, E. P., BRAZHENKO, A. I., STANISLAVSKII, A. A. and LECACHEUX, A., 2008. Decameter Type III-Like Bursts. Sol. Phys. vol. 250, is. 1, pp. 133–145. DOI: https://doi.org/10.1007/s11207-008-9166-z

9. MELNIK, V. N., BRAZHENKO, A. I., KONOVALENKO, A. A., BRIAND, C., DOROVSKYY, V. V., ZARKA, P., FRANTSUZENKO, A. V., RUCKER, H. O., RUTKEVYCH, B. P., PANCHENKO, M., DENIS, L., ZAQARASHVILI, T. and SHERGELASHVILI, B., 2015. Decameter Type III Bursts with Changing Frequency Drift-Rate Signs. Sol. Phys. vol. 290, is. 1, pp. 193–203. DOI: https://doi.org/10.1007/s11207-014-0577-8

10. MELNIK, V. N., KONOVALENKO, A. A., RUCKER, H. O., BOIKO, A. I., DOROVSKYY, V. V., ABRANIN, E. P. and LECACHEUX, A., 2011. Observations of Powerful Type III Bursts in the Frequency Range 10–30 MHz. Sol. Phys. vol. 269, is. 2, pp. 335–350. DOI: https://doi.org/10.1007/s11207-010-9703-4

11. DOROVSKYY, V. V., MELNIK, V. N., KONOVALENKO, A. A., RUCKER, H. O., ABRANIN, E. P. and LECACHEUX, A., 2011. Unusual Type III Bursts at the Decameter Wavelengths. In: H.O. RUCKER, W.S. KURTH, P. LOUARN, and G. FISCHER, ed. Planetary Radio Emissions VII: Proceedings of the 7th International Workshop on Planetary, Solar and Heliospheric Radio Emissions. Vienna, Austria: Austrian Academy of Sciences Press, pp. 359–366. DOI: https://doi.org/10.1553/PRE7s359

12. RUTKEVYCH, B. P. and MELNIK, V. N., 2011. Numerical Simulation of the Propagation of Type III Radio Emission. In: H.O. RUCKER, W.S. KURTH, P. LOUARN, and G. FISCHER, ed. Planetary Radio Emissions VII: Proceedings of the 7th International Workshop on Planetary, Solar and Heliospheric Radio Emissions. Vienna, Austria: Austrian Academy of Sciences Press, pp. 391–398. DOI: https://doi.org/10.1553/PRE7s391

13. MELNIK, V., SHEPELEV, V., BRAZHENKO, A., DOROVSKYY, V., RUCKER, H. and POEDS, S., 2017. Interferometer Observations of Solar Type III Bursts by the Radio Telescope UTR-2. Sun Geosph. vol. 12, no. 2, pp. 105–109.

14. BASELYAN, L.L, GONCHAROV, N. YU., ZAITSEV, V. V., ZINICHEV, V. A., RAPOPORT, V. O. and TSYBKO, YA. G., 1974. 1974. Frequency and Time Splitting of Decameter Solar Radio Bursts. II: Chains. Sol. Phys. vol. 39, is. 1, pp. 223–231. DOI: https://doi.org/10.1007/BF00154983

15. BASELYAN, L.L, GONCHAROV, N. YU., ZAITSEV, V. V., ZINICHEV, V. A., RAPOPORT, V. O. and TSYBKO, YA. G., 1974. Frequency and Time Splitting of Decameter Solar Radio Bursts. I: Elementary events. Sol. Phys. vol. 39, is. 1, pp. 213–222. DOI: https://doi.org/10.1007/BF00154982

16. ABRANIN, E. P., BAZELYAN, L. L., GONCHAROV, N. YU., ZAITSEV, V. V., ZINICHEV, V. A., RAPOPORT, V. O. and TSYBKO, YA. G., 1978. Angular sizes of stria-burst sources in the range 24–26 MHz. Sol. Phys. vol. 57, is. 1, pp. 229–235. DOI: https://doi.org/10.1007/BF00152056

17. ABRANIN, E. P., BAZELYAN, L. L. and TSYBKO, YA. G., 1984. Harmonic relation of type IIIb-III solar radio bursts in 6.25, 12.5, and 25.0 MHz octaves. Sol. Phys. vol. 91, is. 2, pp. 377–381. DOI: https://doi.org/10.1007/BF00146306

18. TSYBKO, YA. G., 1984. Harmonic components of decametric solar radio bursts. Sol. Phys. vol. 92, is. 1-2, pp. 299–315. DOI: https://doi.org/10.1007/BF00157253

19. MELNIK, V. N., RUCKER, H. O., KONOVALENKO, A. A., SHEVCHUK, N. V., ABRANIN, E. P., DOROVSKYY, V. V. and LECACHEUX, A., 2010. Type IIIb bursts and their fine structure in frequency band 18–30 MHz. AIP Conf. Proc. vol. 1206, is. 1, pp. 445–449. DOI: https://doi.org/10.1063/1.3292552

20. SHEVCHUK, M. V., MELNIK, V. N., POEDTS, S., DOROVSKYY, V. V., MAGDALENIC, J. and KONOVALENKO, A. A., 2018. On the Observational Properties of the Decameter Striae. In: 2018 2nd URSI Atlantic Radio Science Meeting (AT-RASC) Proceedings. Meloneras, Spain, 28 May – 1 June, 2018. DOI: https://doi.org/10.23919/URSI-AT-RASC.2018.8471315

21. DOROVSKYY, V. V., MELNIK, V. N., KONOVALENKO, O. O., RUKER, H. O., ABRANIN, E. P. and LECACHEUX, A., 2010. Solar U- and J-Bursts at the Decameter Waves. Radio Phys. Radio Astron. vol. 15, no. 1, pp. 5–14. (in Russian). DOI: https://doi.org/10.1063/1.3292550

22. DOROVSKYY, V. V., MELNIK, V. N., KONOVALENKO, A. A., BUBNOV, I. N., GRIDIN, A. A., SHEVCHUK, N. V., RUCKER, H. O., POEDTS, S. and PANCHENKO, M., 2015. Decameter U-burst Harmonic Pair from a High Loop. Sol. Phys. vol. 290, is. 1, pp. 181–192. DOI: https://doi.org/10.1007/s11207-014-0615-6

23. MEL’NIK, V. N., KONOVALENKO, A. A., RUCKER, H. O., STANISLAVSKY, A. A., ABRANIN, E. P., LECACHEUX, A., MANN, G., WARMUTH, A., ZAITSEV, V. V., BOUDJADA, M. Y., DOROVSKII, V. V., ZAHARENKO, V. V., LISACHENKO, V. N. and ROSOLEN, C., 2004. Observations of Solar Type II bursts at frequencies 10–30 MHz. Sol. Phys. vol. 222, is. 1, pp. 151–166. DOI: https://doi.org/10.1023/B:SOLA.0000036854.66380.a4

24. 24. MEL’NIK, V. N., RUCKER, H. O., KONOVALENKO, A. A., DOROVSKYY, V. V., ABRANIN, E. P., BRAZHENKO, A. I., THIDE, B. and STANISLAVSKYY, A. A., 2008. Solar Type IV Bursts at Frequencies 10–30 MHz. In: P. WANG, ed. Solar Physics Research Trends. New York: Nova Science Publ., pp. 287–325.

25. DOROVSKYY, V. V., MELNIK, V. N., KONOVALENKO, A. A., BRAZHENKO, A. I., PANCHENKO, M., POEDTS, S. and MYKHAYLOV, V. A., 2015. Fine and Superfine Structure of the Decameter-Hectometer Type II Burst on 7 June 2011. Sol. Phys. vol. 290, is. 7, pp. 2031–2042. DOI: https://doi.org/10.1007/s11207-015-0725-9

26. DOROVSKYY, V., MELNIK, V., KONOVALENKO, A., BRAZHENKO, A. and RUCKER, H., 2017. Spatial properties of the complex decameter type II burst observed on 31 May 2013. Sun Geosphere. vol. 13, no. 1,pp. 25–30. DOI: https://doi.org/10.31401/SandG.2018.01.04

27. ANTONOV, A. V., MELNIK, V. N., KONOVALENKO, A. A., DOROVSKYY, V. V., RUCKER, H. O., ZAQARASHVILI, T., STANISLAVSKY, A. A. and KOVAL, A. A., 2014. Decameter Type IV Bursts, Fiber-Bursts and Type III Bursts Associated with Group of Solar Active Regions. Radio Phys. Radio Astron. vol. 19, no. 4, p. 295–306. DOI: https://doi.org/10.15407/rpra19.04.295

28. KONOVALENKO, A. A., STANISLAVSKY, A. A., ABRANIN, E. P., DOROVSKY, V. V., MEL’NIK, V. N., KAISER, M. L., LECACHEUX, A. and RUCKER, H. O., 2007. Absorption in Burst Emission. Sol. Phys. vol. 245, is. 2, pp. 345–354. DOI: https://doi.org/10.1007/s11207-007-9049-8

29. ZLOTNIK, E. Y., ZAITSEV, V. V., MELNIK, V. N., KONOVALENKO, A. A. and DOROVSKYY, V. V., 2015. ‘Fingerprint’ Fine Structure in the Solar Decametric Radio Spectrum. Sol. Phys. vol. 290, is. 7, pp. 2013–2030. DOI: https://doi.org/10.1007/s11207-015-0724-x

30. DOROVSKYY, V. V., MEL’NIK, V. N., KONOVALENKO, A. A., RUCKER, H. O., ABRANIN, E. P. and LECACHEUX, A., 2006. Observations of Solar S-bursts at the decameter wavelengths. In: H. O. RUCKER, W. S. KURTH, and G. Mann, ed. Planetary Radio Emissions VI: Proceedings of the 6th International Workshop on Planetary, Solar and Heliospheric Radio Emissions. Vienna, Austria: Austrian Academy of Sciences Press, pp. 383–390.

31. BRIAND, C., ZASLAVSKY, A., MAKSIMOVIC, M., ZARKA, P., LECACHEUX, A., RUCKER, H. O., KONOVALENKO, A. A., ABRANIN, E. P., DOROVSKY, V. V., STANISLAVSKY, A. A. and MELNIK, V. N., 2008. Faint solar radio structures from decametric observations. Astron. Astrophys. vol. 490, no. 1,pp. 339–344. DOI: https://doi.org/10.1051/0004-6361:200809842

32. MELNIK, V. N., KONOVALENKO, A. A., RUCKER, H. O., DOROVSKYY, V. V., ABRANIN, E. P., LECACHEUX, A. and LONSKAYA, A. S., 2010. Solar S-bursts at Frequencies of 10 - 30 MHz. Sol. Phys. vol. 264, is. 1, pp. 103–117. DOI: https://doi.org/10.1007/s11207-010-9571-y

33. DOROVSKYY, V. V., MELNIK, V. N., KONOVALENKO, A. A., BRAZHENKO, A., POEDTS, S., RUCKER, H. O. and PANCHENKO, M., 2017. Properties of groups of solar S-bursts in the decameter band. In: G. FISHER, G. MANN, M. PANCHENKO, and P. ZARKA, ed. Planetary Radio Emissions VIII: Proceedings of the 8th International Workshop on Planetary, Solar and Heliospheric Radio Emissions. Vienna, Austria: Austrian Academy of Sciences Press, pp. 369–378.

34. CLARKE, B. P., MOROSAN, D. E., GALLAGHER, P. T., DOROVSKYY, V. V., KONOVALENKO, A. A. and CARLEY, E. P., 2019. Properties and magnetic origins of solar S-bursts. Astron. Astrophys. vol. 622, id. A204. DOI: https://doi.org/10.1051/0004-6361/201833939

35. ABRANIN, E. P., BAZELYAN, L. L., GONCHAROV, N. YU., ZAITSEV, V. V., ZINICHEV, V. A., LEVIN, B. N., RAPOPORT, V. O. and TSYBKO, YA. G., 1977. Some results of observations of solar radio bursts of the “drifting pairs” type near frequencies of 25 and 12.5 MHz. Sov. Astron. vol. 21, no. 1, pp. 82–88.

36. MELNIK, V. N., KONOVALENKO, A. A., DOROVSKYY, V. V., RUCKER, H. O., ABRANIN, E. P., LISACHENKO, V. N. and LECACHEUX, A., 2005. Solar Drift Pair Bursts in the Decameter Range. Sol. Phys. vol. 231, is. 1-2, pp. 143–155. DOI: https://doi.org/10.1007/s11207-005-8272-4

37. MELNIK, V. N., SHEVCHUK, N. V., KONOVALENKO, A. A., RUCKER, H. O., DOROVSKYY, V. V., POEDTS, S. and LECACHEUX, A., 2014. Solar Decameter Spikes. Sol. Phys. vol. 289, is. 5, pp. 1701–1714. DOI: https://doi.org/10.1007/s11207-013-0434-1

38. SHEVCHUK, N. V., MELNIK, V. N., POEDTS, S., DOROVSKYY, V. V., MAGDALENIC, J., KONOVALENKO, A. A., BRAZHENKO, A. I., BRIAND, C., FRANTSUZENKO, A. V., RUCKER, H. O. and ZARKA, P., 2016. The Storm of Decameter Spikes During the Event of 14 June 2012. Sol. Phys. vol. 291, is.1, pp. 211–228. DOI: https://doi.org/10.1007/s11207-015-0799-4

39. BAZELYAN, L. L., 1986. Slowly varying local solar decameter sources? Sov. Astron. Lett. vol. 12, no. 2, pp. 110–112.

40. MELNIK, V. N., BRAZHENKO, A. I., KONOVALENKO, A. A., RUCKER, H. O., FRANTSUZENKO, A. V., DOROVSKYY, V. V., PANCHENKO, M. and STANISLAVSKYY, A. A., 2014. Unusual Solar Radio Burst Observed at Decameter Wavelengths. Sol. Phys. vol. 289, is. 1, pp. 263–278. DOI: https://doi.org/10.1007/s11207-013-0328-2

41. STANISLAVSKY, A. A., 2017. Solar type III bursts with high-frequency cut-off. Astronomische Nachrichten. vol. 338, is. 4, pp. 407–412. DOI: https://doi.org/10.1002/asna.201613141

42. SHERGELASHVILI, B. M., MELNIK, V. N., DIDIDZE, G., FICHTNER, H., BRENN, G., POEDTS, S., FOYSI, H., KHODACHENKO, M. L. and ZAQARASHVILI, T. V., 2020. A new class of discontinuous solar wind solutions. Mon. Not. R. Astron. Soc. vol. 496, is. 2, pp. 1023–1034. DOI: https://doi.org/10.1093/mnras/staa1396

43. ABRANIN, E. P. and BAZELYAN, L. L., 1986. Decametric radiation of the quiet Sun. Kharkiv, Ukraine. Institute for Radiophysics and Electronics, Academy of Sciences of Ukrainian SSR. Preprint № 304, 32 p. (in Russian).

44. STANISLAVSKY, A. A. and KOVAL, A. A., 2013. Solar Corona Elliptical Model. Radio Phys. Radio Astron. vol. 18, no. 1, p. 3–11. (in Russian)

45. BRAZHENKO, A. I., KOVAL, A. A., KONOVALENKO, A. A., STANISLAVSKY, A. A., ABRANIN, E. P., DOROVSKYY, V. V., MELNIK, V. M., VASHCHISHIN, R. V., FRANTSUZENKO, A. V. and BORYSYUK, O. V., 2012. Peculiarity of Continuum Emission from Upper Corona of the Sun at Decameter Wavelengths. Radio Phys. Radio Astron. vol. 17, no. 1, p. 3–14. (in Russian). DOI: https://doi.org/10.1615/RadioPhysicsRadioAstronomy.v3.i3.10

46. MELNIK, V. N., SHEPELEV, V. A., POEDTS, S., DOROVSKYY, V. V., BRAZHENKO, A. I. and RUCKER, H. O., 2018. Interferometric Observations of the Quiet Sun at 20 and 25 MHz in May 2014. Sol. Phys. vol. 293, is. 6, id. 97. DOI: https://doi.org/10.1007/s11207-018-1316-3

47. SHEPELEV, V. А., 2015. Determination of Angular Parameters of the Sources of Solar Radio Emission at Decameter Wavelengths. Radio Phys. Radio Astron. vol. 20, no. 1, pp. 20–29. (in Russian). DOI: https://doi.org/10.15407/rpra20.01.020