Abstract
Active region NOAA 7360 was observed in 1992 December with various instruments including the Yohkoh satellite. In this region, a small loop emerged near one of the footpoints of a pre-existing large coronal loop. These loops show evidence that interactions between coronal loops cause flares, microflares, and plasma flow. All of the four flares observed in this region show that brightenings in the small loop occurred first, and then the large loop flared up. The brightenings in the large loop can not occur by themselves, but must be triggered by the brightenings in the small loop. There must be interactions between the loops to cause these flares. As well as the flares, many microflares occurred in the small loop. More than half of them are accompanied by plasma ejection phenomena from the small loop into the large loop. The large loop is filled with ejected plasma with velocities of about 1000 km s−1. These ejection phenomena are considered as X-ray jets. The associated occurrences of the microflares and the jets suggest that they are also caused by interactions between the loops. The recurrent occurrences of the homologous flares and microflares mean that the magnetic field structure in this region inevitably causes the activity due to loop-loop interactions; the flares and jets occur under a common magnetic field structure.
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References
Bastian, T. S. and Gary, D. E.: 1992, Solar Phys. 139, 357.
Benz, A. O.: 1993, Plasma Astrophysics, Kluwer Academic Publishers, Dordrecht, Holland.
de Jager, C., Inda-Koide, M., Koide, S., and Sakai, J. I.: 1995, Solar Phys. 158, 391.
Hanaoka, Y.: 1994, Astrophys. J. 420, L37.
Hara, H., Tsuneta, S., Lemen, J. R., Acton, L. W., and McTiernan, J. M.: 1992, Publ. Astron. Soc. Japan, 44, L135.
Heyvaerts, J., Priest, E. R., and Rust, D. M.: 1977, Astrophys. J. 216, 123.
Inda-Koide, M., Sakai, J.-I, Koide, S., Kosugi, T., Sakao, T., and Shimizu, T.: 1995, Publ. Astron. Soc. Japan 47, 323.
Kosugi, T., Makishima, K., Murakami, T., Sakao, T., Dotani, T., Inda, M., Kai, K., Masuda, S., Nakajima, H., Ogawara, Y., Sawa, M., and Shibasaki, K.: 1991, Solar Phys. 136, 17.
Kundu, M. R., Rust, D. M., and Bobrowsky, M.: 1983, Astrophys. J. 265, 1084.
Lang, K. R. and Willson, R. F.: 1989, Astrophys. J. 344, L77.
Machado, M. E., Somov, B. V., Rovira, M. G., and de Jager, C.: 1983, Solar Phys. 85, 157.
Machado, M. E., Xiao, Y. C., Wu, S. T., Prokakis, Th., and Dialetis, D.: 1988a, Astrophys. J. 326, 451.
Machado, M. E., Moore, R. L., Hernandez, A. M., Rovira, M. G., Hagyard, M. J., and Smith, Jr., J. B.: 1988b, Astrophys, J. 326, 425.
Mandrini, C. H., Démoulin, P., Hénoux, J. C., and Machado, M. E.: 1991, Astron. Astrophys. 250, 541.
Martin, S. F. and Švestka, Z. F.: 1988, Solar Phys. 116, 91.
Masuda, S., Kosugi, T., Hara, H., Tsuneta, S., and Ogawara, Y.: 1995, Nature 371, 495.
Nakajima, H., Dennis, B. R., Hoyng, P., Nelson, G., Kosugi, T., and Kai, K.: 1985, Astrophys. J. 288, 806.
Nakajima, H., Nishio, M., Enome, S., Shibasaki, K., Takano, T., Hanaoka, Y., Torii, C., Sekiguchi, H., Bushimata, T., Kawashima, S., Shinohara, N., Irimajiri, Y., Koshiishi, H., Kosugi, T., Shiomi, Y., Sawa, M., and Kai, K.: 1994, Proceedings IEEE 82, 705.
Ogawara, Y., Takano, T., Kato, T., Kosugi, T., Tsuneta, S., Watanabe, T., Kondo, I., and Uchida, Y.: 1991, Solar Phys. 136, 1.
Rosner, R., Tucker, W. H., and Vaiana, G. S.: 1978, Astrophys. J. 220, 643.
Rust, D. M. and Webb, D. F.: 1977, Solar Phys. 54, 403.
Rust, D. M., Simnett, G. M., and Smith, D. F.: 1985, Astrophys. J. 288, 401.
Sakai, J.-I. and de Jager, C.: 1991, Solar Phys. 134, 329.
Shibata, K., Ishido, Y., Acton, L. W., Strong, K. T., Hirayama, T., Uchida, Y., McAllister, A. H., Matsumoto, R., Tsuneta, S., Shimizu, T., Hara, H., Sakurai, T., Ichimoto, K., Nishino, Y., and Ogawara, Y.: 1992, Publ. Astron. Soc. Japan 44, L173.
Shibata, K., Nitta, N., Matsumoto, R., Tajima, T., Yokoyama, T., Hirayama, T., and Hudson, H.: 1994, in Y. Uchida, T. Watanabe, K. Shibata, and H. S. Hudson (eds.), ‘X-ray Solar Physics from Yohkoh’, Proceedings of the International Symposium on the Yohkoh Scientific Results, Universal Academy Press, Tokyo, p. 29.
Shimizu, T., Tsuneta, S., Acton, L. W., Lernen, J. R., Ogawara, Y., and Uchida, Y.: 1994, Astrophys. J. 422, 906.
Shimizu, T.: 1995, Publ. Astron. Soc. Japan 47, 251.
Shimojo, M., Hashimoto, S., Shibata, K., Hirayama, T., Hudson, H. S., and Acton, L. W.: 1995, Publ. Astron. Soc. Japan, submitted.
Švestka, Z., Fárník, F., and Tang, F.: 1990, Solar Phys. 127, 149.
Švestka, Z. F., Fárník, F., Fontenla, J. M., and Martin, S. F.: 1989, Solar Phys. 123, 317.
Tang, F. and Moore, R. L.: 1982, Solar Phys. 77, 263.
Thomas, R. J., Starr, R., and Crannell, C. J.: 1985, Solar Phys. 95, 323.
Tsuneta, S., Acton, L., Bruner, M., Lemen, J., Brown, W., Caravalho, R., Catura, R., Freeland, S., Jurcevich, B., Morrison, M., Ogawara, Y., Hirayama, T., and Owens, J.: 1991, Solar Phys. 136, 37.
van Driel-Gesztelyi, L., Schmieder, B., Mandrini, C., Démoulin, P., Cauzzi, G., Hofmann, A., Nitta, N., Kurokawa, H., Mein, N., and Mein, P.: 1995, presentation in IAU Colloq. 153.
Willson, R. F., Lang, K. R., and Gary, D. E.: 1993, Astrophys. J. 418, 490.
Yokoyama, T. and Shibata, K.: 1994, in S. Enome and T. Hirayama (eds.), ‘New Look at the Sun with Emphasis on Advanced Observations of Coronal Dynamics and Flares’, Proceedings of Kofu Symposium, NRO Report 360, Nobeyama Radio Observatory, p. 367.
Yokoyama, T. and Shibata, K.: 1995, Nature 375, 42.
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Hanaoka, Y. Flares and plasma flow caused by interacting coronal loops. Sol Phys 165, 275–301 (1996). https://doi.org/10.1007/BF00149715
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DOI: https://doi.org/10.1007/BF00149715