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Variations of the Coronal Radiation in X-ray Related to Coronal Holes, Active Region Loop Systems, Bright Points

Published online by Cambridge University Press:  12 April 2016

Ester Antonucci*
Affiliation:
Istituto di Fisica Generale, University of Torino, 10125 Torino, Italy

Abstract

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The coronal features observed in X-ray emission, varying from the small-scale, short-lived bright points to the large-scale, long-lived coronal holes, are closely associated with the coronal magnetic field and its topology, and their variability depends strongly on the solar cycle. Here we discuss the spatial distribution of the coronal structures, the frequency distribution of the brightness variations in active regions, and the role of magnetic reconnection in determining the variability of the coronal features, on the basis of the new observations of the soft X-ray emission recently obtained with the Yohkoh satellite and the NIXT experiment.

Type
Variability of Solar and Stellar Irradiance Related to the Network, Active Regions (Sunspots and Plages), and Large-Scale Magnetic Structures
Copyright
Copyright © Kluwer 1994

References

Antonucci, E. & Svalgaard, L. 1974 Rigid and differential rotation of the solar corona. Solar Physics 34, 310.Google Scholar
Antonucci, E., Hoeksema, J.T. & Scherrer, P.H. 1990 Rotation of the photospheric magnetic fields: a north-south asymmetry. The Astrophysical Journal 360, 296304.Google Scholar
Athay, R.G. & White, O.R. 1978 Chromospheric and coronal heating by sound waves. The Astrophysical Journal 226, 11351139.Google Scholar
Athay, R.G. & White, O.R. 1979 Chromospheric oscillations observed with OSO 8. II. Average power spectra for Si II. The Astrophysical Journal Suppl. 39, 333346.Google Scholar
Bai, T. 1987 Sub-second variations of high-energy (≥ 300 keV) hard X-ray emission from solar flares. In Rapid Fluctuations in Solar Flares NASA CP-2449, 2933.Google Scholar
Bohlin, J.D. 1977 Extreme-ultraviolet observations of coronal holes. I: Locations, sizes and evolution of coronal holes, June 1973 - January 1974, Solar Physics 51, 377398.CrossRefGoogle Scholar
Cheng, C.-C. 1987 A search for fast variations in the Fe XXI emission during solar flares. In Rapid Fluctuations in Solar Flares NASA CP-2449, 263269.Google Scholar
Cliver, E., Reames, D., Kahler, S. & Cane, H. 1991 Size distribution of solar energetic particle events. Proc. 22nd Int. Cosmic Ray Conf. 3, 2528.Google Scholar
Crosby, N.B., Aschwanden, M.J. & Dennis, B.R. 1993 Frequency distributions and correlations of soft X-ray flare parameters. Solar Physics 143, 275299.Google Scholar
Datlowe, D.W., Elcan, M.J., & Hudson, H.S. 1974 OSO-7 observations of solar X-rays in the energy range 10 - 100 keV. Solar Physics 39, 155174.CrossRefGoogle Scholar
Davis, J.M. 1985 Small-scale flux emergence and the evolution of equatorial coronal holes. Solar Physics 95, 7382.CrossRefGoogle Scholar
De Jager, C. & De Jonge, G. 1978 Properties of elementary flare bursts. Solar Physics 58, 127137.Google Scholar
Dere, K.P., Bartoe, J.-D.F. & Brueckner, G.E. 1984 High-resolution telescope and spectrograph observations of the quiet solar chromosphere and transition zone. The Astro-physical Journal 281, 870883.CrossRefGoogle Scholar
Dere, K.P., Bartoe, J.-D.F., Brueckner, G.E. & Recely, F. 1989 Transition zone flows observed in a coronal hole on the solar disk. The Astrophysical Journal 345, L95L97.Google Scholar
Desai, U.D., Kouveliotou, C, Barat, C., Hurley, K., Niel, M., Talon, R. & Ve-Drenne, G. 1987 Persistent time intervals between features in solar flare hard X-ray emission. In Rapid Fluctuations in Solar Flares NASA CP-2449, 6374.Google Scholar
Doschek, G.A., Feldman, U. & Bohlin, J.D. 1976 Doppler wavelength shifts of transition zone lines measured in Skylab solar spectra. The Astrophysical Journal 205, L177L180.Google Scholar
Drake, J.F. 1971 Characteristics of soft solar X-ray bursts. Solar Physics 16, 152185.Google Scholar
Forrest, D.J. & Chupp, E.L. 1983 Simultaneous acceleration of electrons and ions in solar flares. Nature 305, 291292.Google Scholar
Gerassimenko, M., Solodyna, C.V. & Nolte, J.T. 1978 Observational evidence of continual heating in X-ray emitting coronal loops. Solar Physics 57, 103110.CrossRefGoogle Scholar
Golub, L. 1980 X-ray bright points and the solar cycle. Proc. Roy. Soc. A. 297, 595604.Google Scholar
Golub, L., Krieger, A.S., Silk, J.K., Timothy, A.F. & Vaiana, G.S. 1974 Solar X-ray bright points. The Astrophysical Journal 189, L93L97.Google Scholar
Golub, L., Krieger, A.S., Vaiana, G.S. & Harvey, J.W. 1977 Magnetic properties of X-ray bright points. Solar Physics 53, 111121.CrossRefGoogle Scholar
Golub, L., Davis, J.M. & Krieger, A.S. 1979 Anticorrelation of X-ray bright points with sunspot number, 1970 - 1978, The Astrophysical Journal 229, L145L150.Google Scholar
Golub, L., et al. 1990 Subarcsecond observations of the solar X-ray corona. Nature 344, 842844.CrossRefGoogle Scholar
Gomez, D.O., Martens, P.C.H. & Golub, L. 1993a Normal incidence X-ray telescope power spectra of X-ray emission from solar active regions. I. Observations. The Astrophysical Journal 405, 767772.Google Scholar
Gomez, D.O., Martens, P.C.H. & Golub, L. 1993b Normal incidence X-ray telescope power spectra of X-ray emission. II. Theory. The Astrophysical Journal 405, 773781.Google Scholar
Habbal, S.R. & Withbroe, G.L. 1981 Spatial and temporal variations of EUV coronal bright points. Solar Physics 69, 7797.Google Scholar
Harvey, K.L., Nitta, N., Strong, K.T. & Tsuneta, S. 1993 The relationship of X-ray bright points to the photospheric magnetic fields. In preparation.Google Scholar
Hoyng, P., Brown, J.C. & Van Beek, H.F. 1976 High time resolution analysis of solar hard X-ray flares observed on board the ESRO TD-1A satellite. Solar Physics 48, 197254.Google Scholar
Hoeksema, J.T. & Scherrer, P.H. 1987 Rotation of the coronal magnetic field. The Astro-physical Journal 318, 428436.Google Scholar
Hudson, H.S. 1991 Solar flares, microflares, nanoflares, and coronal heating. Solar Physics 133, 357369.Google Scholar
Hurley, K., Niel, M., Talon, R., Estulin, I.V. & Dolidze, V.Ch. 1983 Multispacecraft hard X-ray observations offine time structure in two solar flares. The Astrophysical Journal 265, 10761983.Google Scholar
Kahler, S.W. & Moses, D. 1990 Discrete changes in solar coronal hole boundaries. The Astrophysical Journal 362, 728733.Google Scholar
Kane, S.R., Kai, K., Kosugi, T., Enome, S., Landecker, P.B. & Mckenzie, D.L. 1983 Acceleration and confinement of energetic particles in the 1980 June 7 solar flare. The Astrophysical Journal 271, 376387.Google Scholar
Kaufmann, P., Correia, E., Costa, J.E.R., Dennis, B.R., Hurford, G.J. & Brown, J.C. 1984 Multiple energetic injections in a strong spike-like solar burst. Solar Physics 91, 359376.CrossRefGoogle Scholar
Kiplinger, A.L., Dennis, B.R., Frost, K.J. & Orwig, L.E. 1983 Recurrent pulse trains in the solar hard X-ray flare of 1980 June 7. The Astrophysical Journal 273, 783794.CrossRefGoogle Scholar
Kosugi, T. & Kiplinger, A.L. 1987 Quasi-periodic pulsations in solar hard X-ray and microwave flares. In Rapid Fluctuations in Solar Flares NASA CP-2449, 185191.Google Scholar
Levine, R.H., Altschuler, M.D., Harvey, J.W. & Jackson, B.V. 1977 Open magnetic structures on the Sun. The Astrophysical Journal 215, 636651.Google Scholar
Lin, R.P., Schwartz, R.A., Kane, S.R., Pelling, R.M. & Hurley, K.C. 1984 Solar hard X-ray microflares. The Astrophysical Journal 283, 421425.Google Scholar
Lin, R.P., Hurley, K.C., Smith, D.M. & Pelling, R.M. 1991 A search for hard X-ray microflares near solar minimum. Solar Physics 135, 5764.CrossRefGoogle Scholar
Linford, G.A. & Wolfson, C.J. 1988 Properties of an impulsive compact solar flare determined from Solar Maximum Mission X-ray measurements. The Astrophysical Journal 331, 10361046.Google Scholar
Lu, E.T. & Hamilton, R.J. 1991 Avalanches and the distribution of solar flares. The Astro-physical Journal 380, L89L92.Google Scholar
Martens, P.C.H., Van Den Oord, G.H.J. & Hoyng, P. 1985 Observations of steady anomalous magnetic heating in thin current sheets. Solar Physics 96, 253275.Google Scholar
Martens, P.C.H. & Gomez, D.O. 1992 Spatial power-spectra from Yohkoh soft X-ray images. PASJ 44, L187L191.Google Scholar
Mewe, R. 1972 Calculated solar X-ray radiation from 1 to 60 Å. Solar Physics 22, 459491.Google Scholar
Nakajima, H., Kosugi, T., Kai, K. & Enome, S. 1983 Successive electron and ion accelerations in impulsive solar flares on 7 and 21 June 1980, Nature 305, 292294.Google Scholar
Nash, A.G., Sheeley, N.R. Jr., & Wang, Y.-M. 1988 Mechanisms for rigid rotation of coronal holes. Solar Physics 117, 359389.Google Scholar
Neupert, W.M. 1968 Comparison of solar X-ray line emission with microwave emission during flares. The Astrophysical Journal 153, L59L64.Google Scholar
Nolte, J.T., Krieger, A.S. & Solodyna, C.V. 1978a Short term evolution of coronal hole boundaries. Solar Physics 57, 129139.Google Scholar
Nolte, J.T., Davis, J.M., Gerassimenko, M., Krieger, A.S., Solodyna, C.V. & Golub, L. 1978b The relationship between solar activity and coronal hole evolution. Solar Physics 60, 143153.CrossRefGoogle Scholar
Parker, E.N. 1987 Stimulated dissipation of magnetic discontinuities and the origin of solar flares. Solar Physics 111, 297308.Google Scholar
Parker, E.N. 1988 Nanofiares and the solar X-ray corona. The Astrophysical Journal 330, 474479.Google Scholar
Porter, J.G. 1992 Microflares observed with UVSP and HXIS. In Coronal Streamers, Coronal Loops, and Coronal and Solar Wind Composition ESA, SP, 348, 289292.Google Scholar
Porter, J.G., Toomre, J. & Gebbie, K.B. 1984 Frequent ultraviolet brightenings observed in a solar active region with Solar Maximum Mission. The Astrophysical Journal 283, 879886.Google Scholar
Porter, J.G., Moore, R.L., Reichmann, E.J., Engvold, O. & Harvey, K.L. 1987 Microflares in the solar magnetic network. The Astrophysical Journal 323, 380390.Google Scholar
Rosner, R. & Vaiana, G.S. 1978 Cosmic flare transients: constraints upon models for energy storage and release derived from the event frequency distribution. The Astrophysical Journal 222, 11041108.Google Scholar
Rosner, R., Tucker, W.H. & Vaiana, G.S. 1978a Dynamics of the quiescent solar corona. The Astrophysical Journal 220, 643665.Google Scholar
Rosner, R., Golub, L., Coppi, B. & Vaiana, G.S. 1978b Heating of coronal plasma by anomalous current dissipation. The Astrophysical Journal 222, 317332.Google Scholar
Roussel-Dupré, D. & Shine, R.A. 1982 Evidence of redshifts in the average solar line profiles of C IV ans Si IV from OSO-8 observations. Solar Physics 77, 329340.Google Scholar
Rust, D.M. 1983 Coronal disturbances and their terrestrial effects. Space Sci. Rev. 34, 2136.Google Scholar
Schatten, K.H., Wilcox, J.M. & Ness, N.F. 1969 A model of interplanetary and coronal magnetic fields. Solar Physics 6, 442455.Google Scholar
Sheeley, N.R. Jr., 1980 Temporal variations of loop structures in the solar atmosphere. Solar Physics 66, 7987.Google Scholar
Sheeley, N.R. Jr., & Harvey, J.W. 1981 Coronal holes, solar wind streams, and geomagnetic disturbances during 1978 and 1979. Solar Physics 70, 237249.Google Scholar
Shimizu, T., Tsuneta, S., Acton, L.W., Lemen, J.R. & Uchida, Y. 1992 Transient brightenings in active regions observed by the Soft X-ray Telescope on Yohkoh . PASJ 44, L147L153.Google Scholar
Strong, K.T., Harvey, K.L., Hirayama, T., Nitta, N., Shimizu, T. & Tsuneta, S. 1992 Observations of the variability of coronal bright points by the Soft X-ray Telescope on Yohkoh . PASJ 44, L161L166.Google Scholar
Sturrock, P.A. 1987 Rapid fluctuations in solar flares. In Rapid Fluctuations in Solar Flares NASA CP-2449, 128.Google Scholar
Sturrock, P.A., Kaufmann, P., Moore, R.L. & Smith, D.F. 1984 Energy release in solar flares. Solar Physics 94, 341357.Google Scholar
Timothy, A.F., Krieger, A.S. & Vaiana, G.S. 1975 The structure and evolution of coronal holes. Solar Physics 42, 135156.Google Scholar
Thomas, R.J., Neupert, W.M. & Thompson, W.T. 1987 Soft X-ray oscillations during the flare of 7 August 1972. In Rapid Fluctuations in Solar Flares NASA CP-2449, 299300.Google Scholar
Tsuneta, S. & Lemen, J.R. 1993 Dynamics of the solar corona observed with the Yohkoh Soft X-ray Telescope. In Physics of Solar and Stellar Coronae: G.S. Vaiana Memorial Symposium (eds. Linsky, J.F. and Serio, S.), pp. 113130. Kluwer Academic Publishers.Google Scholar
Uchida, Y., McAllister, A., Strong, K.T., Ogawara, Y., Shimizu, T., Matsumoto, R. & Hudson, H.S. 1992 Continual expansion of the active-region corona observed by the Yohkoh Soft X-ray Telescope. PASJ 44, L155L160.Google Scholar
Van Hollebeke, M.A.I., MA Sung, L.S. & McDonald, F.B. 1975 The variation of solar proton energy spectra and size distribution with heliolongitude. Solar Physics 41, 189223.Google Scholar
Wagner, W.J. 1975 Solar rotation as marked by extreme-ultraviolet coronal holes. The As-trophysical Journal 198, L141L144.Google Scholar
Webb, D.F. 1981 Active region structures in the transition region and corona. In Solar Active Regions. A Monograph from Skylab Solar Workshop III (ed. Orrall, F.Q.). pp. 165198. Colorado Associated University Press, Boulder, CO., USA. Google Scholar
Webb, D.F., McIntosh, P.S., Nolte, J.T. & Solodyna, C.V. 1978 Evidence linking coronal transients to the evolution of coronal holes. Solar Physics 58, 389396.Google Scholar
Zarro, D.M., Saba, J.L.R. & Strong, K.T. 1987 Rapid soft X-ray fluctuations in solar flares observed with the X-ray Polychromator. In Rapid Fluctuations in Solar Flares NASA CP-2449, 289298.Google Scholar
Zirker, J.B. 1976 Energy balance in coronal holes and solar wind streams. In The Energy Balance and Hydrodynamics of the Solar Chromosphere and Corona (ed. Bonnet, R.-M. & Delache, P.). 421445.Google Scholar
Zirker, J.B. & Cleveland, F.M. 1993 Avalanche models of active region heating and flaring. Solar Physics 145, 119128.Google Scholar