Space Science Reviews

, 159:263

Microflares and the Statistics of X-ray Flares

  • I. G. Hannah
  • H. S. Hudson
  • M. Battaglia
  • S. Christe
  • J. Kašparová
  • S. Krucker
  • M. R. Kundu
  • A. Veronig
Article

DOI: 10.1007/s11214-010-9705-4

Cite this article as:
Hannah, I.G., Hudson, H.S., Battaglia, M. et al. Space Sci Rev (2011) 159: 263. doi:10.1007/s11214-010-9705-4

Abstract

This review surveys the statistics of solar X-ray flares, emphasising the new views that RHESSI has given us of the weaker events (the microflares). The new data reveal that these microflares strongly resemble more energetic events in most respects; they occur solely within active regions and exhibit high-temperature/nonthermal emissions in approximately the same proportion as major events. We discuss the distributions of flare parameters (e.g., peak flux) and how these parameters correlate, for instance via the Neupert effect. We also highlight the systematic biases involved in intercomparing data representing many decades of event magnitude. The intermittency of the flare/microflare occurrence, both in space and in time, argues that these discrete events do not explain general coronal heating, either in active regions or in the quiet Sun.

Keywords

SunFlaresX-rays

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • I. G. Hannah
    • 1
  • H. S. Hudson
    • 2
  • M. Battaglia
    • 1
  • S. Christe
    • 3
  • J. Kašparová
    • 4
  • S. Krucker
    • 2
  • M. R. Kundu
    • 5
  • A. Veronig
    • 6
  1. 1.School of Physics & AstronomyUniversity of GlasgowGlasgowUK
  2. 2.Space Sciences LaboratoryUniversity of California at BerkeleyBerkeleyUSA
  3. 3.NASA Goddard Space Flight CenterGreenbeltUSA
  4. 4.Astronomický ústav AV ČROndřejovCzech Republic
  5. 5.Dept. of AstronomyUniv. of MarylandCollege ParkUSA
  6. 6.Institute of Physics/IGAMUniversity of GrazGrazAustria