A NANOFLARE HEATING MODEL AND COMPARISON WITH OBSERVATIONS
- Department of Astronomy, School of Science, University of Tokyo, Bunkyo-ku, 113-0033 Tokyo (Japan)
- National Astronomical Observatory, 2-21-1, Ohsawa, Mitaka, 181-8588 Tokyo (Japan)
- School of Physics and Astronomy, University of Manchester, Manchester, M60 1QD (United Kingdom)
A nanoflare-heated coronal loop model is developed based on the model of Vekstein and Katsukawa. We performed numerical simulations based on the model, and then compared the results with the Yohkoh/Soft X-ray Telescope (SXT) and Transition Region and Coronal Explorer (TRACE) observations. We found that the most significant difference between hot (>2 MK) SXT loops and cool (approx1 MK) TRACE loops is the energy of nanoflares and the magnetic field strength. Energy of individual nanoflares is 10{sup 24-25} erg for SXT loops, and 10{sup 23} erg for TRACE loops. This is derived from the observed intensity fluctuations. To observed mean intensities, we require the model SXT loops to have a stronger magnetic field than the TRACE loops, 40 G and 8 G, respectively. The model predicts two characteristic properties of nanoflare-heated coronal loops: (1) the SXT and TRACE light curves of a coronal loop show weak cross-correlation with a lag time corresponding to the cooling timescale. (2) SXT loops have a smaller volumetric filling factor than TRACE loops. We consider that this difference in the filling factor makes SXT loops look more diffuse than TRACE loops.
- OSTI ID:
- 21371848
- Journal Information:
- Astrophysical Journal, Vol. 703, Issue 2; Other Information: DOI: 10.1088/0004-637X/703/2/2118; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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