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A major proton event of 2005 January 20: propagating supershock or superflare?

A major proton event of 2005 January 20: propagating supershock or superflare?. V. Grechnev 1 , V. Kurt 2 , A. Uralov 1 , H.Nakajima 3 , A. Altyntsev 1 , L. Kashapova 1 , N. Meshalkina 1 et al. 1 Institute of Solar-Terrestrial Physics, Irkutsk 2 Moscow State University, Moscow

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A major proton event of 2005 January 20: propagating supershock or superflare?

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  1. A major proton event of 2005 January 20: propagating supershock or superflare? V.Grechnev1, V.Kurt2, A. Uralov1, H.Nakajima3,A. Altyntsev1, L. Kashapova1, N. Meshalkina1et al. 1Institute of Solar-Terrestrial Physics, Irkutsk 2Moscow State University, Moscow 3Nobeyama Radio Observatory, Nobeyama

  2. Protons SXR The event of 2005 January 20 • Speedest (>5000 km/s) CME ever registered with LASCO @ 4.4R (06:54 UT) • Protons >700 cm-2s-1sr-1 with E>100 MeV came soon • GLE of 277 %, largest in the 23th cycle • -ray emission • X7.1/2B • Microwave flux ~ 105 sfu

  3. Problem in question • Gopalswamy et al. (2005, 29th ICRC, 101): common shock origin for type II radio bursts and GLEs • Simnett (2006, A&A 445, 715): CME was not responsible for the relativistic ion acceleration ¿Where high-energy protons were accelerated?

  4. Available data • The event observed in X-rays and -rays: • Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) • non-imaging Solar Neutron and Gamma spectrometer (SONG) on board CORONAS-F spacecraft from 06:43:30 on • -rays up to 100 MeV • TRACE in 1600 Å line from 06:53:30 on • Nobeyama Radio Polarimeters (NoRP) • No NoRH observations (too late)

  5. TRACE RHESSI SONG HXR and -ray time profiles HXR and -ray time profiles

  6. RHESSI/HXR & SXR, TRACE 1600 Å Background:TRACE 1600 Å.No images between 06:18 and 06:52:30 Red: RHESSI SXR Blue: RHESSI HXR(50-100 kev?) GOES/SXI: Movie: http://svs.gsfc.nasa.gov/vis/a000000/a003100/a003161/

  7. Comparison of TRACE 1600 Å and HXR 50-100 keV images • One can expect correlation of bright kernels in TRACE 1600 Å and HXR • This can be used for coalignment • The interval of 06:52:30-06:57 • Variance and averaged images  06:52 06:47 06:57

  8. Ribbons in TRACE 1600 Å images • Variance map Time profiles • Averaged image

  9. Outcome from TRACE 1600 Å images: • 8 bright kernels at the outer parts of ribbons • 4 regions with well-pronounced counterparts  4 loops: • Formation of a usual (low) arcade • Try to compare with RHESSI 50-100 keV images 

  10. Comparison of 1600 Å and HXR bright kernels • White: 50-100 keV kernels • Black: 1600 Å kernels • Bottom: shift +7.5, -10.5  satisfactory coalignment • Now we can find relative positions of sunspots, ribbons, and X-ray sources 

  11. White Light 50-100 keV 6-12 keV 1600 Å ribbon Relative positions of sunspots, ribbons, and X-ray sources • Ribbons crossed sunspots • Large SXR loop-like structure

  12. S N 50-100 keV RHESSI images • N-footpoint fixed • S-footpoint moves eastwards • HXR are weaker from N-footpoint •  BN-foot > BS-foot, N-footpoint needs more counterparts

  13. Evolution of AR 10720 B = 1800 G • Magnetograms: one week of SOHO/MDI observations, Jan 12-20 • All images “co-rotated” to Jan 15, 00 UT •  B > 2000 Gin N-polarity sunspot overturn

  14. Stokes I Stokes V Source B Source A NoRP data Note: Y scales in 103 sfu

  15. peak, GHz Flux, 103 sfu   Frequency , GHz NoRP spectra

  16. Source B Source A NoRP data suggest • Source A: 35 GHz < peak < 80 GHz in N-sunspot, B > 2000 G • Source B: peak < 35 GHz in S-polarity region, first in weaker sunspot, then moved eastwards • One or two more sources in weaker magnetic fields •   -(0.6-1.3)    1.8-2.5 • Microwave emission was produced by large amount of hard electrons in strong magnetic fields

  17. EM d/dt(GOES 1-8 Å) 17 GHz T 34 GHz Ne 300-800 keV GOES/SXI  SXR GOES data • Loop: h=50 Mm, l=2.6 Mm, d=0.9 Mm, V=8·1027 cm3 • Neupert effect & trapping: GOES 10 GOES 12

  18. Features of the event • Long bundle of loops rooted in sunspots • Trapping & harder microwaves  large mirroring expectable in a large loop • Many accelerated particles (estimated from microwave fluxes) • Strong magnetic fields

  19. HXR & -ray images and spectrum •  = 2.7 – softer than microwaves suggest • Nuclear lines 0.51 & 2.2 MeV All images are confined to the active region

  20. Ground-Level Enhancement • Perfect coincidence • No dispersion with respect to -rays • Delay of ~380 s • Solar wind disturbed (ACE: ~800 km/s) - path length longer • Leading edge was a bunch of ultrarelativistic protons

  21. Conclusion • 2.2 MeV line is due to collisions of MeV-energy protons with dense layers • The 2.2 MeV source image is located in region of closed magnetic structures • Protons from remote outer source have no access into the closed structures in AR  Protons could be accelerated only in AR • On the other hand, protons accelerated in the current sheet are injected both down and up, and the latter reach the Earth to produce GLE

  22. F35 > 104 sfu  15 of 649 events Wasthis event exceptional? Date Peak 35 GHz 80 GHz Protons GLE Position Flare L&B Gopal 1990-04-15 02:59 19615 No data N32E57 X1.4 1990-05-21 22:14 37913 29083 + + N35W36 X5.5 + 1991-03-22 22:44 122522 12469 + S26E28 X9.4 + 1991-03-29 06:45 10871 2196 ? S28W60 X2.4 1991-05-18 05:13 20429 3376 ? N32W85 X2.8 1991-06-04 03:41 131163 165816 + N30E65 X12 + 1991-06-06 01:08 130439 186980 + N33E44 X12 + 1991-06-09 01:38 73994 23630 + N34E04 X10 + 1991-06-11 02:05 45671 10025 + + N31W17 X12 + 1991-10-24 02:38 33967 10637 S15E60 X2.1 1992-11-02 02:49 41312 12000 + 15% S23W90 X9 + 2001-04-02 21:47 24952 15600Weak 1% N17W78 X20 2002-07-23 00:30 14821 6000S13E72 X4.8 2002-08-24 01:00 11477 4300+ 5% S02W81 X3.1 + 2005-01-20 06:46 84500 50000 + 277% N14W61 X7.1 + 2000-11-08 23:28 weak weak strong N20W66 M7.4 + 2001-04-18 02:14 48 + 14% S23W92 C2.2+ 2001-12-26 05:05 764 111 + 7% N07W62 M7.1 +

  23. Summary • High-energy protons in 2005 January 20 event were accelerated on the Sun, within the active region • 2005 January 20 event was a major proton flare • Moreover, it was a typical major proton flare • Microwave emission in such events is generated by large number of electrons with hard spectrum in strong magnetic fields

  24. We acknowledge • Shibasaki San and NSRO for the opportunity to work here under perfect conditions • Staff members of the NSRO for the hospitality

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