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Magnetic reconnection in large-scale cosmic plasmas


X-ray emitting hot plasmas of a temperature 2–12 keV, associated with galaxy clusters, constitute the most dominant form of baryons in the universe. The plasma is thought to be magnetized at least to 0.1–1 nT, although the β value is relatively high at 10–100. The plasma is confined by gravity of each cluster in a stable manner, but the member galaxies are moving through it with an approximately transonic speed. Therefore, the plasma must be in a magnetohydrodynamically turbulent condition, where frequent magnetic reconnection is expected to take place. Mainly based on observations with the ASCA X-ray Observatory, evidence for such magnetic reconnection is accumulating.


  1. Drake, N., M. R. Merrifield, I. Sakelliou, and J. C. Pinkney, X-ray wakes in Abell 160, Mon. Not. R. Astr. Soc., 314, 768–774, 2000.

  2. Dressler, A., A. Oemler, Jr., W. B. Sparks, and R. A. Lucas, New images of the distant, rich cluster CL 0939 + 4713 with WFPC2, Astrophys. J., 435, L23–L26, 1994.

  3. Fabian, A. C., Cooling flows in clusters of galaxies, Ann. Rev. Astr. Astrophys., 32, 277–318, 1994.

  4. Fabian, A. C., K. A. Arnaud, M. W. Bautz, and Y. Tawara, ASCA observations of cooling flows in clusters of galaxies, Astrophys. J., 436, L63-L66, 1994.

  5. Fukazawa, Y. et al., Metal concentration and X-ray cool spectral component in the central region of the Centaurus cluster of galaxies, Pub. Astr. Soc. Japan, 46, L55-L58, 1994.

  6. Fukazawa, Y. et al., Statistical properties of metal abundances of the intracluster medium in the central region of clusters, Mon. Not. R. Astr. Soc., 313, 21–31, 2000.

  7. Fukazawa, Y. et al., Detection of excess hard X-ray emission from the group of galaxies HCG 62, Astrophys. J. Lett., 547, L119-L122, 2001.

  8. Fusco-Femiano, R. et al., Hard X-ray radiation in the Coma cluster spectrum, Astrophys. J., 513, L21-L24, 1999.

  9. Ge, J. and F. N. Owen, Faraday rotation in cooling flow clusters of galaxies. 2: Survey, Astron. J., 108, 1523–1533, 1994.

  10. Ikebe, Y., et al., Structure of the X-Ray—emitting gas in the Hydra A cluster of galaxies, Astrophys. J., 481, 660–672, 1997.

  11. Ikebe, Y., et al., Two-phase intracluster medium in the Centaurus cluster of galaxies, Astrophys. J., 525, 58–79, 1999.

  12. Kaastra, J. S., et al., High- and low-energy nonthermal X-ray emission from the Abell 2199 cluster of galaxies, Astrophys. J., 519, L119-L122, 1999.

  13. Kano, R. and S. Tsuneta, Scaling law of solar coronal loops obtained with Yohkoh, Astrophys. J., 454, 934–944, 1995.

  14. Kronberg, P. P., Extragalactic magnetic fields, Rep. Prog. Phys., 325–382, 1994.

  15. Lieu, R., M. Bonamente, and J. P. D. Mittaz, Extreme-ultraviolet images of the clusters of galaxies A2199 and A1795, Astrophys. J., 517, L91–L95, 1999.

  16. Makishima, K., X-ray probing of the galaxy/cluster interface, in UV and X-ray Spectroscopy of Astrophysical and Laboratory Plasmas, edited by K. Yamashita and T. Watanabe, pp. 167–173, Universal Academy Press, Tokyo, 1996.

  17. Makishima, K., Magnetohydrodynamic interpretations of high-energy phenomena in galaxies and clusters, Plasma Phys. Control. Fusion, 39, A15–A21, 1997a.

  18. Makishima, K., Magnetohydrodynamic (MHD) view of plasmas in galaxies and clusters, in Imaging and Spectroscopy of Cosmic Hot Plasmas, edited by F. Makino and K. Mitsuda, pp. 137–148, Universal Academy Press, Tokyo, 1997b.

  19. Makishima, K., From the sun to the galaxy clusters, in Observational Plasma Astrophysics: Five Years of Yohkoh and Beyond, edited by T. Watanabe, T. Kosugi, and A. Sterling, pp. 51–60, Kluwer Academic, Dordrecht, 1999a.

  20. Makishima, K., Energy non-equipartition processes in the Universe, Astronomische Nachrichten, 320, 161–166, 1999b.

  21. Moore, B., N. Katz, G. Lake, A. Dressler, and A. Oemler, Jr., Galaxy harassment and the evolution of clusters of galaxies, Nature, 379, 613–616, 1996.

  22. Mulchaey, J., D. Davis, R. Mushotzky, and D. Burstein, The intragroup medium in poor groups of galaxies, Astrophys. J., 456, 80–97, 1996.

  23. Ramirez, A. and R. E. de Souza, Shape of the galactic orbits in clusters, Astrophys. J., 496, 693–705, 1998.

  24. Rosner, R., W. Tucker, and G. Vaiana, Dynamics of the quiescent solar corona, Astrophys. J., 643, 643–665, 1978.

  25. Sarazin, C. L., X-Ray Emission from Clusters of Galaxies, Cambridge University Press, 1988.

  26. Sarazin, C. L. and J. Kempner, Nonthermal bremsstrahlung and hard X-ray emission from clusters of galaxies, Astrophys. J., 533, 73–83, 2000.

  27. Sarazin, C. L. and R. Lieu, Extreme-ultraviolet emission from clusters of galaxies, Astrophys. J., 494, L177–L180, 1998.

  28. Takahashi, T. et al, Development of the Hard X-ray Detector for the ASTRO-E mission, Astron. Astrophys. Suppl, 120, 645–648, 1996.

  29. Takeda, M. et al, Extension of the cosmic-ray energy spectrum beyond the predicted GZK cutoff, Phys. Rev. Lett., 81, 1163–1166, 1998.

  30. Tamura, T, K. Makishima, Y. Fukazawa, Y. Ikebe, and H. Xu, X-ray measurements of the gravitational potential profile in the central region of the Abell 1060 cluster of galaxies, Astrophys. J., 535, 602–614, 2000.

  31. Tanaka, Y., H. Inoue, and S. S. Holt, The X-ray astronomy satellite ASCA, Pub. Astr. Soc. Japan, 46, L37–L39, 1994.

  32. Whitmore, B. C. and D. M. Gilmore, What determines the morphological fractions in clusters of galaxies?, Astrophys. J., 407, 489–509, 1993.

  33. Xu, H., K. Makishima, Y. Fukazawa, Y. Ikebe, K. Kikuchi, T. Ohashi, and T. Tamura, Discovery of the central excess brightness in hard X-rays in the cluster of galaxies Abell 1795, Astrophys. J., 500, 738–749, 1998.

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Correspondence to Kazuo Makishima.

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Makishima, K. Magnetic reconnection in large-scale cosmic plasmas. Earth Planet Sp 53, 677–681 (2001).

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  • Dark Matter
  • Magnetic Reconnection
  • Spiral Galaxy
  • Galaxy Cluster
  • Stellar Mass