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Bauman Moscow State Technical University.   El № FS 77 - 48211.   ISSN 1994-0408

Analysis of Hard X-Ray, Microwave and Millimeter Emission in Solar Flare Plasma on 5 July 2012

# 12, December 2016
DOI: 10.7463/1216.0852397
Article file: SE-BMSTU...o097.pdf (1040.38Kb)
authors: V.V. Smirnova1,*, Yu.T. Tcap2, A.V. Shumov3, A.S. Morgachev4, G.G. Motorina1, V.S. Ryzhov3, N.A. Jarkova3, V.G. Nagnibeda5

1 The Central Astronomical Observatory of the Russian Academy of Sciences
at Pulkovo, Saint-Petersburg, Russia

2 Crimean Astrophysical Observatory of the Russian Academy of Sciences,
Nauchny, Crimea, Russia

Bauman Moscow State Technical University, Moscow, Russia

4 Scientific Research Institute of Radio Physics of the "National Research
Nizhny Novgorod State University n.a. N.I. Lobachevskii ",
Nizhny Novgorod, Russia

5 Astronomical Institute .n.a. V.V. Sobolev of the St. Petersburg State
University, St. Petersburg, Russia

Bauman Moscow State Technical University’s  (BMSTU’s) radiotelescope RT-7.5  is in continuous operation to observe the active regions on the Sun at frequencies of 93 and 140 GHz (3.2 and 2.2 mm, respectively). A special attention is focused on the observations of solar flares. The given frequency range is understudied, but it allows us to have the unique information about the physical parameters of the chromospheric plasma of flare loops (Shustikov et al. 2015).
The paper is aimed at a detailed study and interpretation of the characteristic features of the spectrum of solar flare radio emission observed using the BMSTU radio telescope RT-7.5 at frequencies of 93 and 140 GHz in case there is a radio flux density growth with frequency. A positive slope of the sub-THz spectrum of radio emission was earlier  observed only from time to time at frequencies of 200 and 400 GHz (Kaufmann et al., 2009). Currently, the interpretation of this effect is still under discussion due to a lack of sufficient observational material with the desired frequency resolution in the sub-THz range (Krucker et al., 2013).
The paper, using the July 5, 2012 flare event of X-class GOES M6.1 as an example, through numerical simulation of the radio flux density spectrum shows that the observed positive spectral slope of this flare between the frequencies of 93 and 140 GHz can be explained by available single population of low- and high-energy electrons, the generation of which occurs in the solar chromosphere-transition region of the Sun. It could be suggested that the effective electron acceleration occurs in the chromosphere, rather than, as previously thought, only at the coronal level.
The section 1 briefly describes the observational data and methods of their obtaining and processing. The section 2 presents the main result of numerical modelling of the radio spectrum. The section 3 offers discussion of results and conclusions.
The work was completed under support of the Russian Science Foundation Grant 16-12-10448 and partly under support of the Grants 15-02-08028 A and 16-32-00535 of the Russian Foundation for Fundamental Research.

  1. Ryzhov V.S., Zhil'tsov A.V., Shumov A.V., Shustikov V.Iu. Dolgovremennye nabliudeniia millimetrovogo radioizlucheniia solnechnykh vspyshek na radioteleskope RT-7,5 MGTU. 20 International Scientific and Technical Conference on Radiolocation, Navigation and Communication. 2014. P. 1821-1831.
  2. Shustikov V.Iu., Shumov A.V., Ryzhov V.S., Zhil'tsov A.V. Rezul'taty nabliudenii millimetrovogo radioizlucheniia solnechnykh vspyshek na radioteleskope RT-7.5 MGTU im. N.E. Baumana. Inzhenernyi zhurnal: nauka i innovatsii = Engineering Journal: Science and Innovation. 2012. No. 8. Available at:http://engjournal.ru/catalog/pribor/radio/337.html, accessed 01.08.2015.
  3. Shustikov V.Iu., Shumov A.V., Tsap Iu.T., Zharkova N.A., Morgachev A.S., Motorina G.G., Kontar' E.P., Nagnibeda V.G., Ryzhov V.S., Smirnova V.V., Strekalova P.V. Modelirovanie sub-millimetrovoi chasti spektra radioizlucheniia solnechnykh vspyshek. Nauka I obrazovanie = Science and education. Electronic scientific and technical publication. 2015. No. 9. P. 106-121. DOI:10.7463/0915.0812079
  4. Brown J.C., Mallik P.C.V. Flare Hard X-Ray Sources Dominated by Nonthermal Recombination. The Astrophysical Journal Letters. Vol. 697. Iss. 1. P. L6-L9. DOI:10.1088/0004-637X/697/1/L6
  5. Chertok I.M., Fomichev V.V., Gorgutsa R.V., Hildebrandt J., Krüger A., Magun A., Zaitsev V.V. Solar radio bursts with a spectral flattening at millimeter wavelengths. Solar Physics. 1995. Vol. 160, is. 1. P. 181-198. DOI:10.1007/BF00679104
  6. Fleishman G.D., Kontar E.P. Sub-Thz radiation mechanisms in solar flares. The Astrophysical Journal Letters. 2010. Vol. 709, no. 2. P. L127-L132. DOI:10.1088/2041-8205/709/2/L127
  7. Fleishman G.D., Kuznetsov A.A. Fast gyrosynchrotron codes. The Astrophysical Journal Letters. 2010. Vol. 721. No. 2. P. 1127-1141. DOI:10.1088/0004-637X/721/2/1127
  8. Gimenez de Castro C.G., Trottet G., Silva-Valio A. et al. Submillimeter and X-ray observations of an X class flare. Astronomy & Astrophysics. 2009. Vol. 507, no. 1. P. 433-439. DOI:10.1051/0004-6361/200912028
  9. Kaufmann P., Raulin J.-P., Correia E., Costa J.E.R., Guillermo C., de Castro Giménez, Silva A.V.R., Levato H., Rovira M., Mandrini C., Fernández-Borda R., Bauer O. Solar flare observations at submm-waves. Proceedings of IAU Symposium. Vol. 203. Publ. by Astronomical Society of the Pacific. 2001. P. 283-286.
  10. Kaufmann P., Trottet G., Gimenez de Castro C.G., Raulin J.-P., Krucker S., Shih A.Y., Levato H. Sub-terahertz, Microwaves and High Energy Emissions During the 6 December 2006 Flare, at 18:40 UT. Solar Physics. 2009. Vol. 255, is. 1. P. 131-142. DOI:10.1007/s11207-008-9312-7
  11. Krucker S., Gimenez de Castro C.G., Hudson H.S., et al. Solar flares at submillimeter wavelengths. The Astronomy and Astrophysics Review. 2013. Vol. 21. Art. id. 58. DOI:10.1007/s00159-013-0058-3
  12. Lemen J.R., Title A.M., Akin D.J., et al. The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO). Solar Physics. 2012. Vol. 275, is. 1. P. 17-40. DOI:10.1007/s11207-011-9776-8
  13. Lin R.P., Dennis B.R., Hurford G.J., et al. The Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). Solar Physics. 2002. Vol. 210, is. 1. P. 3-32. DOI:10.1023/A:1022428818870
  14. Luthi T., Magun A., Miller M. First observation of a solar X-class flare in the submillimeter range with KOSMA. Astronomy & Astrophysics. 2004. Vol. 415. P. 1123-1132. DOI:10.1051/0004-6361:20034624
  15. Raulin J.-P., White S.M., Kundu M.R., Silva A.V.R., Shibasaki K. Multiple Components in the Millimeter Emission of a Solar Flare. The Astrophysical Journal Letters. 1999. Vol. 522, no. 1. P. 547. DOI:10.1086/322974
  16. Razin V.A. To the theory of radio emission spectra caused by discrete sources at frequencies lower than 30 MHz. Izvestiya Vysshikh Uchebnykh Zavedenii. Radiofizika. 1960. No. 3. P. 584-594.
  17. Rozanov B.A. Millimeter range radio telescope RT-7,5 BMSTU. Reviews of USSR Universities. Part 3. Radio electronics. 1981. Vol. 3. P. 3-10.
  18. Silva A.V.R., Share G.H., Murphy R.J., Costa J.E.R., Giménez de Castro C.G., Raulin J.-P., Kaufmann P. Evidence that Synchrotron Emission from Nonthermal Electrons Produces the Increasing Submillimeter Spectral Component in Solar Flares. Solar Physics. 2007. Vol. 245, is. 2. P. 311-326. DOI:10.1007/s11207-007-9044-0
  19. Smirnova V.V., Nagnibeda V.G., Ryzhov V.S., Zhil’tsov A.V., Solov’ev A.A. Observations of sub-terahertz radiation of solar flares with an RT-7.5 radiotelescope. Geomagnetism and Aeronomy. 2013. Vol. 53, is 8. P. 997-999. DOI:10.1134/S0016793213080239
  20. Trottet G, Raulin J., Kaufmann P. et al. First detection of the impulsive and extended phases of a solar radio burst above 200 GHz. Astronomy and Astrophysics. 2002. Vol. 381, no. 2. P. 694-702. DOI:10.1051/0004-6361:20011556
  21. Trottet G., Raulin J.-P., Gimenez de Castro G., Lüthi T., Caspi A., Mandrini C.H., Luoni M.L., Kaufmann P. Origin of the submillimeter radio emission during the time-extended phase of a solar flare. Solar Physics. 2011. Vol. 273, is. 2. P. 339-361. DOI:10.1007/s11207-011-9875-6
  22. Tsap Yu.T., Stepanov A.V., Kopylova Yu.G. Ambipolar diffusion and magnetic reconnection. Astronomy Reports. Vol. 56. Iss. 2. P. 138-145. DOI:10.1134/S1063772912020084
  23. Tsap Y.T., Smirnova V.V., Morgachev A.S., Motorina G.G., Kontar E.P., Nagnibeda V.G., Strekalova P.V. On the origin of 140 GHz emission from the 4 July 2012 solar flare. Advances in Space Research. Vol. 57. Iss. 7. P. 1449-1455. DOI:10.1016/j.asr.2015.12.037
  24. White S.M., Thomas R.J., Schwartz R.A. Updated expressions for determining temperatures and emission measures from GOES soft X-ray measurements. Solar Physics. 2005. Vol. 227, is. 2. P. 231-248. DOI:10.1007/s11207-005-2445-z
  25. Zaitsev V.V., Stepanov A.V., Melnikov V.F. Sub-terahertz emission from solar flares: The plasma mechanism of chromospheric emission. Astronomy Letters. Vol. 39. Iss. 9. P. 650-659. DOI:10.1134/S1063773713090089
  26. Zaitsev V.V., Urpo S., Stepanov A.V. Temporal dynamics of Joule heating and DC-electric field acceleration in single flare loop. Astronomy and Astrophysics. Vol. 357. P. 1105-1114
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