480 likes | 614 Views
Search for solar neutrons associated with proton flares in solar cycle 23. Yutaka Matsubara (presenter) Solar-Terrestrial Environment Laboratory, Nagoya University. August, 2005, Pune 29th International Cosmic Ray Conference. Authors.
E N D
Search for solar neutrons associated with proton flares in solar cycle 23 Yutaka Matsubara (presenter) Solar-Terrestrial Environment Laboratory, Nagoya University August, 2005, Pune 29th International Cosmic Ray Conference
Authors Y. Matsubara1, Y. Muraki1, T. Sako1, K. Watanabe1, S. Masuda1, T. Sakai2, S. Shibata3, E. Flückiger4,R. Bütikofer4, A. Chilingarian5, G. Hovsepyan5, Y. H. Tan6, T. Yuda7, M. Ohnishi7, H. Tsuchiya8, Y. Katayose9, R. Ogasawara10, Y. Mizumoto10, M. Nakagiri10, A. Miyashita10, A. Velarde11, R. Ticona11, and N. Martinic11 • Solar-Terrestrial Environment Laboratory, • Nagoya University • (2) College of Industrial Technologies, Nihon University • (3) College of Engineering, Chubu University • (4) Physikalisches Institut, University of Bern • (5) Yerevan Physics Institute • (6) Institute of High Energy Physics, Chinese Academy of Science • (7) Institute for Cosmic Ray Research, University of Tokyo • (8) RIKEN • (9) Facaulty of Engineering, Yokohama National University • (10) National Astronomical Observatory of Japan • (11) Institoto de Investigaciones Fisicas, • Universidad Mayor de San Andres
Contents 1. Motivation 2. Solar neutron telescopes 3. Solar neutrons associated with proton flares 4. Summary
Soft X-rays versus Protons S12W83 X-class S14W47 Aug17 Aug18 Aug19 Apr10 Apr11 Apr12 2004 proton
East limb Soft X-rays versus Protons 2005 Jul26 Jul27 Jul28 Where do these protons come from ?
X-class flares without protons 971127 1259 X 2.6 2B N17E63 8113 980818 2210 X 4.9 1B N33E87 8307 010825 1623 X 5.3 3B S17E34 9591 011213 1420 X 6.2 3B N16E 9 9733 020520 1521 X 2.1 2N S21E65 9961 020703 208 X 1.5 1B S20W51 17 020723 18 X 4.8 2B S13E72 39 020830 1247 X 1.5 SN N15E74 95 030611 2001 X 1.6 1N N14W59 375 031103 943 X 3.9 2F N 8W77 488 040716 1349 X 3.6 3B S11E35 649 040818 1729 X 1.8 SF S12W83 656
What do we search for ? To detect solar neutrons: in the past →We investigated large flares in X-rays To detect solar neutrons: in this work →We investigate proton flares
Summary of solar neutron telescopes Solar neutron telescopes are at good places to observe high energy protons !
GLE: April 2001 40 Counting rate increase (%) 0 Oulu: April 2001
GOES April 18, 2001 X-class Soft-X Apr17 Apr18 Apr19 Proton >10MeV >50MeV >100MeV 3 days
Oulu: 010418 >10% increase around 3 UT
GOES Proton vs Neutron Monitor: 010418 84-200MeV Oulu (0.8GV) 39-82MeV 110-500MeV Higher energy channels increase more rapidly than lower energy channels !
Positionof the Sun 010418 3:30 UT
Norikura vs Tibet: 010418 Tibet >40MeV Norikura >20MeV Both increse around the same time as Oulu
Norikura vs Oulu vs Goes-p: 010418 GOES-p(110-500MeV) Oulu (0.8GV) Norikura (>20MeV) Norikura increased later than others
[ Expected ] neutron>Oulu>GOES-proton [ Obtained ] Oulu>GOES-proton>neutron The Gornergrat and Aragats stations (night) also show increases !!!
010418 (Norikura, Tibet, Gornergra, Aragats) Tibet >40MeV Norikura >20MeV Armenia >40MeV Gornergrat >40MeV
Several solar neutron telescopes show similar time profiles of counting rates on ・March 31, 2001 ・April 15, 2001 (GLE event) ・April 18, 2001 (GLE event) ・October 29, 2003 (GLE event) ・・・・・・ At the moment, no indication of solar neutrons has been detected, but……
Summary ・Solar neutrons have been searched for associated with proton flares by using solar neutron telescopes. (also high energy protons) ・So far, only indications of high energy protons have been accumulated. This study is in progress for events obtained during Solar Cycle 23.
End Thank you very much for your attention !
List of Ground Level Enhancement November 6, 1997 X9.4 May 2, 1998 X1.1 August 24, 1998 X1.0 June 14, 2000 X5.7 April 15, 2001 X14.0 April 18, 2001 M1.3??? November 4, 2001 X1.0 December 26, 2001 M7.1 August 24, 2002 X3.1 October 28, 2003 X17.0 October 29, 2003 X10.0 January 20, 2005 X7.1 by Oulu NM
Neutrons are attenuated in the air 1. Solar neutron telescopes should be at high mountains. near the equator. for charged particles: opposite 2. Solar neutron telescopes should be operated at different longitudes.
Location of neutron monitors 1 10 10 1
Solar neutron telescope can 1. measure energy of neutrons (nm: weak) 2. measure direction of neutrons (nm: never) 3. discriminate neutrons from protons (nm: never)
Understanding from solar neutron telescopes Acceleration time of ions Efficiency of acceleration Direction of acceleration Time and duration of neutron production Total energy of high energy neutrons Relation between neutron observation and flare position Acceleration model Observation Directly connected with ion acceleration
Ground Level Enhancement: 000714 15% 14日 July 2000
GOES July 14, 2000 X-class Soft-X X5.7 Jul13 Jul14 Jul15 Proton >10MeV >100MeV >50MeV 3 days
GOES X-ray vs Proton X-ray 40-80MeV 80-165MeV 165-500MeV Soft X-rays started earlier than protons
GOES Proton vs Neutron Monitor 80-165MeV NM: Apatity (0.65GV) 165-500MeV 40-80MeV Higher energy channels increase more rapidly than lower energy channels
GOES vs Neutron Monitor: 000714 165-500MeV X-ray Apatity Start time of increase of counting rate: (1) X (2) NM (3) GOES-proton
GOES March 31, 2001 X-class Soft-X Mar30 Mar31 Apr1 Proton >10MeV >50MeV >100MeV 3 days
Norikura vs Tibet vs Goes-p: 010331 GOES-p(10-40MeV) Norikura (>20MeV) Tibet (>40MeV) Norikura & Tibet increase later than GOES-p
010331 (Norikura, Tibet, Gornergra, Aragats) Norikura >20MeV Tibet >40MeV Armenia >40MeV Gornergrat >40MeV
GOES April 15, 2001 X-class Soft-X Apr14 Apr15 Apr16 Proton >10MeV >50MeV >100MeV 3 days
Gornergrat vs Oulu vs Goes-p: 010415 GOES-p(84-200MeV) Gornergrat (>40MeV) Oulu(0.8GV) Gornergrat increased most rapidly
010415 (Norikura, Gornergrat, Aragats) Norikura >20MeV Armenia >40MeV Gornergrat >40MeV
GOES June 18, 2003 X-class Soft-X Jun17 Jun18 Jun19 Proton >10MeV >50MeV >100MeV 3 days
GOES Oct 29, 2003 X-class Soft-X Oct28 Oct29 Oct30 >10MeV Proton >50MeV >100MeV 3 days
Gorner. vs Nor. vs Oulu vs Goes-p: 031029 GOES-p (15-40MeV) Oulu(0.8GV) Gornergrat (>40MeV) Norikura >20MeV Gornergrat and GOES-p behave similarly
031029 (Norikura, Tibet, Gornergrat, Aragats) Norikura >20MeV Tibet >40MeV Armenia >40MeV Gornergrat >40MeV
List of >M flare around 010418 010409 1520 M 7.9 2B S21W04 9415 010410 0506 X 2.3 3B S23W09 9415 010411 1256 M 2.3 1F S22W27 9415 010412 0256 M 1.3 1N S22W38 9415 010412 0939 X 2.0 SF S19W43 9415 010414 1715 M 1.0 SF S16W71 9415 010415 1319 X 14.0 2B S20W85 9415 010420 0501 M 1.0 1F N16E63 9433 010420 1951 M 4.1 1F N15E55 9433 010422 2037 M 3.2 1N N14E18 9433 010423 0119 M 1.0 1F N18E18 9433 010423 2015 M 4.0 2N N14E23 9433 010424 0533 M 2.1 1N N18E01 9433