Emission Measure Distribution and Heating of Two Active Region Cores
Abstract
Using data from the Extreme-ultraviolet Imaging Spectrometer aboard Hinode, we have studied the coronal plasma in the core of two active regions. Concentrating on the area between opposite polarity moss, we found emission measure distributions having an approximate power-law form EMvpropT 2.4 from log T = 5.5 up to a peak at log T = 6.55. We show that the observations compare very favorably with a simple model of nanoflare-heated loop strands. They also appear to be consistent with more sophisticated nanoflare models. However, in the absence of additional constraints, steady heating is also a viable explanation.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2011
- DOI:
- 10.1088/0004-637X/740/2/111
- arXiv:
- arXiv:1107.4480
- Bibcode:
- 2011ApJ...740..111T
- Keywords:
-
- Sun: atmosphere;
- Sun: corona;
- Sun: transition region;
- Sun: UV radiation;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 24 pages, 9 Figures, Accepted for Publication in The Astrophysical Journal