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Title: THERMAL NON-EQUILIBRIUM REVISITED: A HEATING MODEL FOR CORONAL LOOPS

The location and frequency of events that heat the million-degree corona are still a matter of debate. One potential heating scenario is that the energy release is effectively steady and highly localized at the footpoints of coronal structures. Such an energy deposition drives thermal non-equilibrium solutions in the hydrodynamic equations in longer loops. This heating scenario was considered and discarded by Klimchuk et al. on the basis of their one-dimensional simulations as incapable of reproducing observational characteristics of loops. In this paper, we use three-dimensional simulations to generate synthetic emission images, from which we select and analyze six loops. The main differences between our model and that of Klimchuk et al. concern (1) dimensionality, (2) resolution, (3) geometrical properties of the loops, (4) heating function, and (5) radiative function. We find evidence, in this small set of simulated loops, that the evolution of the light curves, the variation of temperature along the loops, the density profile, and the absence of small-scale structures are compatible with the characteristics of observed loops. We conclude that quasi-steady footpoint heating that drives thermal non-equilibrium solutions cannot yet be ruled out as a viable heating scenario for EUV loops.
Authors:
; ;  [1] ;  [2] ;  [3]
  1. Predictive Science, Inc., 9990 Mesa Rim Rd., Ste. 170, San Diego, CA 92121-2910 (United States)
  2. NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States)
  3. Department of Physics and Astronomy, University of California, 4129 Reines Hall, Irvine, CA 92697 (United States)
Publication Date:
OSTI Identifier:
22130987
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 773; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DENSITY; ENERGY ABSORPTION; ENERGY LOSSES; GALACTIC EVOLUTION; HYDRODYNAMIC MODEL; IMAGES; MATHEMATICAL SOLUTIONS; ONE-DIMENSIONAL CALCULATIONS; RESOLUTION; SIMULATION; THREE-DIMENSIONAL CALCULATIONS; VISIBLE RADIATION