A nanoflare based cellular automaton model and the observed properties of the coronal plasma

Abstract

We use the cellular automaton model described in López Fuentes \& Klimchuk (2015, ApJ, 799, 128) to study the evolution of coronal loop plasmas. The model, based on the idea of a critical misalignment angle in tangled magnetic fields, produces nanoflares of varying frequency with respect to the plasma cooling time. We compare the results of the model with active region (AR) observations obtained with the Hinode/XRT and SDO/AIA instruments. The comparison is based on the statistical properties of synthetic and observed loop lightcurves. Our results show that the model reproduces the main observational characteristics of the evolution of the plasma in AR coronal loops. The typical intensity fluctuations have an amplitude of 10 to 15\% both for the model and the observations. The sign of the skewness of the intensity distributions indicates the presence of cooling plasma in the loops. We also study the emission measure (EM) distribution predicted by the model and obtain slopes in log(EM) versus log(T) between 2.7 and 4.3, in agreement with published observational values.

arXiv commentPaper 2 of 2: Model comparison with observations. Accepted for publication in ApJ

References in corpus (23)

• On Solving the Coronal Heating Problem
• Highly Efficient Modeling of Dynamic Coronal Loops
• Key Aspects of Coronal Heating
• A Systematic Survey of High Temperature Emission in Solar Active Regions
• Evidence for Widespread Cooling in an Active Region Observed with the SDO Atmospheric Imaging Assembly
• Constraints on the Heating of High Temperature Active Region Loops: Observations from Hinode and SDO
• Enthalpy-based Thermal Evolution of Loops: II. Improvements to the Model
• Coronal Loops: Observations and Modeling of Confined Plasma
• Patterns of Nanoflare Storm Heating Exhibited by an Active Region Observed with SDO/AIA
• The Magnetic Structure of Coronal Loops Observed by TRACE
• Emission Measure Distribution and Heating of Two Active Region Cores
• Diagnosing the time-dependence of active region core heating from the emission measure: I. Low-frequency nanoflares
• Coronal Temperature Diagnostic Capability of the Hinode/X-Ray Telescope Based on Self-Consistent Calibration
• Evidence for Steady Heating: Observations of an Active Region Core with Hinode and TRACE
• Hydrostatic Modeling of the Integrated Soft X-Ray and EUV Emission in Solar Active Regions
• Modeling the Line-of-Sight Integrated Emission in the Corona: Implications for Coronal Heating
• Widespread nanoflare variability detected with Hinode/XRT in a solar active region
• Diagnosing the time-dependence of active region core heating from the emission measure: II. Nanoflare trains
• Determining heating time scales in solar active region cores from AIA/SDO Fe XVIII images
• Are Coronal Loops Isothermal or Multithermal? Yes!
• A simple model for the evolution of multi-stranded coronal loops
• 2D cellular automaton model for the evolution of active region coronal plasmas
• Time-resolved emission from bright hot pixels of an active region observed in the EUV band with SDO/AIA and multi-stranded loop modeling

Cited by in corpus (5)

• The Properties of the Solar Corona and Its Connection to the Solar Wind
• The Heating of Solar Coronal Loops by Alfven Wave Turbulence
• Statistical Signatures of Nanoflare Activity. I. Monte Carlo Simulations and Parameter-space Exploration
• Power-Law Statistics Of Driven Reconnection In The Magnetically Closed Corona
• Hard X-Ray Constraints on Small-Scale Coronal Heating Events