Solar Physics

, Volume 269, Issue 2, pp 295–307 | Cite as

Observational Signatures of Impulsively Heated Coronal Loops: Power-Law Distribution of Energies



It has been established that small scale heating events, known as nanoflares, are important for solar coronal heating if the power-law distribution of their energies has a slope α steeper than −2 (α<−2). Forward modeling of impulsively heated coronal loops with a set of prescribed power-law indices α is performed. The power-law distribution is incorporated into the governing equations of motion through an impulsive heating term. The results are converted into synthetic Hinode/EIS observations in the 40″ imaging mode, using a selection of spectral lines formed at various temperatures. It is shown that the intensities of the emission lines and their standard deviations are sensitive to changes in α. A method based on a combination of observations and forward modeling is proposed for determining whether the heating in a particular case is due to small or large scale events. The method is extended and applied to a loop structure that consists of multiple strands.


Heating, coronal Flares, microflares and nanoflares Spectral line, intensity and diagnostics 


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Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Institute of Mathematics and PhysicsAberystwyth UniversityAberystwythUK
  2. 2.SP²RC, Department of Applied MathematicsUniversity of SheffieldSheffieldUK
  3. 3.Department of Physics and AstronomyRice UniversityHoustonUSA
  4. 4.Solar Physics Lab.NASA Goddard Space Flight CenterGreenbeltUSA

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