Understanding Heating in Active Region Cores through Machine Learning I. Numerical Modeling and Predicted Observables

Abstract

To adequately constrain the frequency of energy deposition in active region cores in the solar corona, systematic comparisons between detailed models and observational data are needed. In this paper, we describe a pipeline for forward modeling active region emission using magnetic field extrapolations and field-aligned hydrodynamic models. We use this pipeline to predict time-dependent emission from active region NOAA 1158 as observed by SDO/AIA for low-, intermediate-, and high-frequency nanoflares. In each pixel of our predicted multi-wavelength, time-dependent images, we compute two commonly-used diagnostics: the emission measure slope and the time lag. We find that signatures of the heating frequency persist in both of these diagnostics. In particular, our results show that the distribution of emission measure slopes narrows and the mean decreases with decreasing heating frequency and that the range of emission measure slopes is consistent with past observational and modeling work. Furthermore, we find that the time lag becomes increasingly spatially coherent with decreasing heating frequency while the distribution of time lags across the whole active region becomes more broad with increasing heating frequency. In a follow up paper, we train a random forest classifier on these predicted diagnostics and use this model to classify real AIA observations of NOAA 1158 in terms of the underlying heating frequency.

32 pages, 12 figures, accepted for publication in The Astrophysical Journal

References in corpus (36)

• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• A Multi-Code Analysis Toolkit for Astrophysical Simulation Data
• Differential Emission Measures from the Regularized Inversion of Hinode and SDO data
• Highly Efficient Modeling of Dynamic Coronal Loops
• Key Aspects of Coronal Heating
• Solar UV and X-Ray Spectral Diagnostics
• A Systematic Survey of High Temperature Emission in Solar Active Regions
• Coronal rain as a marker for coronal heating mechanisms
• 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
• SunPy - Python for Solar Physics
• Enthalpy-based Thermal Evolution of Loops: II. Improvements to the Model
• The multi-thermal and multi-stranded nature of coronal rain
• Using a Differential Emission Measure and Density Measurements in an Active Region Core to Test a Steady Heating Model
• Patterns of Nanoflare Storm Heating Exhibited by an Active Region Observed with SDO/AIA
• Emission Measure Distribution and Heating of Two Active Region Cores
• Non-equilibrium of Ionization and the Detection of Hot Plasma in Nanoflare-heated Coronal Loops
• Diagnosing the time-dependence of active region core heating from the emission measure: I. Low-frequency nanoflares
• On the occurrence of thermal non-equilibrium in coronal loops
• Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores I. Single Nanoflares
• Long-Period Intensity Pulsations in Coronal Loops Explained by Thermal Non-Equilibrium Cycles
• New Observations of the Solar 0.5-5 keV Soft X-ray Spectrum
• The Coronal Monsoon: Thermal Nonequilibrium Revealed by Periodic Coronal Rain
• Can the Differential Emission Measure constrain the timescale of energy deposition
• Diagnosing the time-dependence of active region core heating from the emission measure: II. Nanoflare trains
• Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores. II. Nanoflare Trains
• Coronal fuzziness modelled with pulse-heated multistranded loop systems
• Patterns of Activity in a Global Model of a Solar Active Region
• The Evolution of the EM Distribution in the Core of an Active Region
• Spectroscopy of very hot plasma in non-flaring parts of a solar limb active region: spatial and temporal properties
• The CHIANTI atomic database
• Can a Long Nanoflare Storm Explain the Observed Emission Measure Distributions in Active Region Cores?
• Signatures of Steady Heating in Time Lag Analysis of Coronal Emission
• Identifying Observables that can Differentiate Between Impulsive and Footpoint Heating: Time Lags and Intensity Ratios
• Can Large Time Delays Observed in Light Curves of Coronal Loops be Explained by Impulsive Heating?
• Heating Mechanisms for Intermittent Loops in Active Region Cores from AIA/SDO EUV Observations

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• Assessing the capability of a model-based stellar XUV estimation
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• Temperature and Differential Emission Measure Profiles in Turbulent Solar Active Region Loops
• Transition region contribution to AIA observations in the context of coronal heating
• Nanoflare Diagnostics from Magnetohydrodynamic Heating Profiles
• Multi-Stranded Coronal Loops: Quantifying Strand Number and Heating Frequency from Simulated Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) Observations
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