Abstract
Based on our analysis of the data fromthe global network of neutronmonitors for several events, we have found the times of the first increases in count rate at individual stations that precede the main solar cosmic-ray enhancement. The onset time of proton acceleration at the Sun has been determined from the appearance of a broad gamma-ray line with its maximum near 70 MeV that is generated during the decay of neutral pions, which, in turn, are produced when protons with energies above 300 MeV interact with the solar atmosphere. The time of the first recording of energetic protons at the Earth is delayed relative to the time at which these protons appeared at the Sun by 60–300 s, i.e., by a value comparable to the difference between the direct photon and particle propagation times. At least two conclusions follow from the existence of such “precursors”. First, the protons begin to escape from the solar atmosphere into interplanetary space immediately after their acceleration. Second, some of the protons traverse a path shorter than the nominal length of interplanetary magnetic field lines.
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References
V. V. Akimov et al., Proc. 22 Int. Cosmic Ray Conf. (Dublin) 3, 73 (1991).
V. V. Akimov, N. G. Leikov, V. G. Kurt, et al., Proc. AIP Conf. 294, 130 (1994).
V. V. Akimov, P. Ambrož, A.V. Belov, and I. M. Chertok, Solar Phys. 166, 107 (1996).
J. A. van Allen, Geophys. Res. Lett. 20, 2797 (1993).
A. V. Belov, E. A. Eroshenko, and M. A. Livshits, in Proc. 8th Int. Symp. Solar Terr. Phys., Sendai, Japan, 1994 p. 26.
A.V. Belov and M. A. Livshits, Pis’maAstron. Zh. 21, 42 (1995) [Astron. Lett. 21, 37 (1995)].
A. V. Belov, E. A. Eroshenko, V. G. Yanke, et al., Adv. Space Res. 16, 249 (1995).
A. Belov, H. Garcia, V. Kurt, et al., Solar Phys. 229, 135 (2005).
J. W. Bieber, J. Clem, P. Evenson, et al., Geophys. Res. Lett. 32, L03S02 (2005).
E. L. Chupp, D. J. Forrest, J. M. Ryan, et al., Astrophys. J. 263, L95 (1982).
E. L. Chupp, H. Debrunner, E. Flueckiger, et al., Astrophys. J. 318, 913 (1987).
H. Debrunner, J. A. Lockwood, and J. M. Ryan, Astrophys. J. 409, 822 (1993).
H. Debrunner, J. A. Lockwood, C. Barat, et al., Astrophys. J. 479, 997 (1997).
P. P. Dunphy and E. L. Chupp, Proc. 22 Int. Cosmic Ray Conf. (Dublin) 3, 65 (1991).
P. P. Dunphy and E. L. Chupp, Proc. AIP Conf. 294, 112 (1994).
P. P. Dunphy, E. L. Chupp, D. L. Bertsch, et al., Solar Phys. 187, 45 (1999).
V. V. Grechnev, V. G. Kurt, I. M. Chertok, et al., Solar Phys. 252, 149 (2008).
G. Kanbach, D. Bertsch, C. Fichtel, et al., Astron. Astrophys. Suppl. Ser. 97, 349 (1993).
G. A. Kovaltsov, I. G. Usoskin, L. G. Kocharov, et al., Solar Phys. 158, 355 (1995).
V. G. Kurt, B. Yu. Yushkov, K. Kudela, and V. I. Galkin, Kosmich. Issled. 48, 72 (2010).
S. N. Kuznetsov, V. G. Kurt, B. Yu. Yushkov, et al., Int. J. Modern Phys. A 20, 6705 (2005).
S. N. Kuznetsov, V. G. Kurt, I. N. Myagkova, et al., Astron. Vestnik 40, 120 (2006a).
S. N. Kuznetsov, V. G. Kurt, B. Yu. Yushkov, and K. Kudela, Izv. RAN, Ser. Fiz. 70, 1457 (2006b).
S. N. Kuznetsov, V. G. Kurt, B. Yu. Yushkov, and K. Kudela, Proc. 30th Int. Cosmic Ray Conf. (Merida) 1, 121 (2008).
S. N. Kuznetsov, V. G. Kurt, B. Yu. Yushkov, et al., Solar Phys. (2010, in press).
L. I. Miroshnichenko, K.-L. Klein, G. Trottet, et al., J. Geophys. Res. 110, A09S08 (2005).
L. I. Miroshnichenko, E. V. Vashenyuk, and J. Perez-Peraza, Izv. RAN, Ser. Fiz. 73, 314 (2009).
V. Moses and P. Evenson, Astrophys. J. 346, 523 (1989).
R. J. Murphy, C. D. Dermer, and R. Ramaty, Astrophys. J. Suppl. Ser. 63, 721 (1987).
C. Pei, J. R. Jokipii, and J. Giacalone, Astrophys. J. 641, 1222 (2006).
J. Perez-Peraza, E. V. Vashenyuk, L. I. Miroshnichenko, et al., Astrophys. J. 695, 865 (2009).
C. Plainaki, A. Belov, E. Eroshenko, et al., Proc. AIP Conf. 848, 258 (2006).
R. Ramaty, B. Kozlovsky, and R. Lingenfelter, Space Sci. Rev. 18, 341 (1975).
R. Ramaty, R. A. Schwartz, S. Enome, and H. Nakajima, Astrophys. J. 436, 941 (1994).
C. J. Schrijver, H. S. Hudson, R. J. Murphy, et al., Astrophys. J. 650, 1184 (2006).
D. F. Smart, M. A. Shea, and L. C. Gentile, Proc. 23 Int. Cosmic Ray Conf. (Calgary) 3, 55 (1993).
R. Talon, G. Trottet, N. Vilmer, et al., Solar Phys. 147, 137 (1993).
G. Trottet, S. Krucker, T. Lüthi, and A. Magun, Astrophys. J. 678, 509 (2008).
I. S. Veselovskii, M. I. Panasyuk, S. I. Avdyushin, et al., Kosmich. Issled. 42, 453 (2004).
N. Vilmer, F. MacKinnon, G. Trottet, and C. Barat, Astron. Astrophys. 412, 865 (2003).
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Original Russian Text © Viktoriya G. Kurt, B.Yu. Yushkov, A.V. Belov, 2010, published in Pis’ma v Astronomicheskiĭ Zhurnal, 2010, Vol. 36, No. 7, pp. 550–560.
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Kurt, V.G., Yushkov, B.Y. & Belov, A.V. On the ground level enhancement beginning. Astron. Lett. 36, 520–530 (2010). https://doi.org/10.1134/S106377371007008X
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DOI: https://doi.org/10.1134/S106377371007008X