On the Accuracy of the Differential Emission Measure Diagnostics of Solar Plasmas. Application to AIA/SDO. Part II: Multithermal plasmas

Abstract

The Differential Emission Measure (DEM) analysis is one of the most used diagnostic tools for solar and stellar coronae. Being an inverse problem, it has limitations due to the presence of random and systematic errors. We present in theses series of papers an analysis of the robustness of the inversion in the case of AIA/SDO observations. We completely characterize the DEM inversion and its statistical properties, providing all the solutions consistent with the data along with their associated probabilities, and a test of the suitability of the assumed DEM model. While Paper I focused on isothermal conditions, we now consider multi-thermal plasmas and investigate both isothermal and multithermal solutions. We demonstrate how the ambiguity between noises and multi-thermality fundamentally limits the temperature resolution of the inversion. We show that if the observed plasma is multi-thermal, isothermal solutions tend to cluster on a constant temperature whatever the number of passbands or spectral lines. The multi-thermal solutions are also found to be biased toward near isothermal solutions around 1 MK. This is true even if the residuals support the chosen DEM model, possibly leading to erroneous conclusions on the observed plasma. We propose tools to identify and quantify the possible degeneracy of solutions, thus helping the interpretation of DEM inversion.

24 pages, 12 figures

References in corpus (4)

• Differential Emission Measures from the Regularized Inversion of Hinode and SDO data
• Forward modeling of emission in SDO/AIA passbands from dynamic 3D simulations
• On the Accuracy of the Differential Emission Measure Diagnostics of Solar Plasmas. Application to AIA/SDO. Part I: Isothermal plasmas
• Monte Carlo Markov Chain DEM reconstruction of isothermal plasmas

Cited by in corpus (40)

• Thermal Diagnostics with the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory: A Validated Method for Differential Emission Measure Inversions
• Advances in Observing Various Coronal EUV Waves in the SDO Era and Their Seismological Applications (Invited Review)
• Photometric and Thermal Cross-calibration of Solar EUV Instruments
• On The Fourier And Wavelet Analysis Of Coronal Time Series
• Evidence for evaporation-incomplete condensation cycles in warm solar coronal loops
• On the occurrence of thermal non-equilibrium in coronal loops
• Long-Period Intensity Pulsations in Coronal Loops Explained by Thermal Non-Equilibrium Cycles
• On the Accuracy of the Differential Emission Measure Diagnostics of Solar Plasmas. Application to AIA/SDO. Part I: Isothermal plasmas
• Flux rope, hyperbolic flux tube, and late EUV phases in a non-eruptive circular-ribbon flare
• The Coronal Monsoon: Thermal Nonequilibrium Revealed by Periodic Coronal Rain
• Can the Differential Emission Measure constrain the timescale of energy deposition
• Energy release from impacting prominence material following the 2011 June 7 eruption
• Order out of Randomness : Self-Organization Processes in Astrophysics
• Diagnosing the time-dependence of active region core heating from the emission measure: II. Nanoflare trains
• Benchmark Test of Differential Emission Measure Codes and Multi-Thermal Energies in Solar Active Regions
• Sparkling EUV bright dots observed with Hi-C
• Nanoflare distributions over solar cycle 24 based on SDO/AIA differential emission measure observations
• Energetic characterisation and statistics of solar coronal brightenings
• The spectroscopic imprint of the pre-eruptive configuration resulting into two major coronal mass ejections
• Spectroscopy of very hot plasma in non-flaring parts of a solar limb active region: spatial and temporal properties
• The Slowly Varying Corona: I --- Daily Differential Emission Measure Distributions Derived from EVE Spectra
• Thermal non-equilibriuem revealed by periodic pulses of random amplitudes in solar coronal loops
• The characteristics of flare- and CME-productive solar active regions
• Expanding and Contracting Coronal Loops as Evidence of Vortex Flows Induced by Solar Eruptions
• Imaging and spectroscopic observations of extreme-ultraviolet brightenings using EUI and SPICE on board Solar Orbiter
• The Solar Minimum Eclipse of 2019 July 2. III. Inferring the Coronal $T_e$ with a Radiative Differential Emission Measure Inversion
• Relative Abundance Measurements in Plumes and Interplumes
• Small-scale magnetic flux emergence preceding a chain of energetic solar atmospheric events
• SPICE Connection Mosaics to link the Sun's surface and the heliosphere
• Empirical relations between the intensities of Lyman lines of H and He${}^{+}$
• Reconnection generated plasma flows in the quasi-separatrix layer in localised solar corona
• The Slowly Varying Corona. II. The Components of F ${}_{10.7}$ and Their Use in EUV Proxies
• Multiscale statistical analysis of coronal solar activity
• Temperature Analysis of Flaring (AR11283) and non-Flaring (AR12194) Coronal Loops
• Solar Atmospheric Magnetic Energy Coupling: Broad Plasma Conditions and Spectrum Regimes
• Helical flows along coronal loops following the launch of a coronal mass ejection
• A Multiwavelength Analysis of the Long-duration Flare Observed on 15 April 2002
• An Approximate Bayesian Deep Learning Approach for Uncertainty-aware Differential Emission Measure Estimates in the Solar Corona from the SDO
• The Quiet-Sun DEM Under Kappa: Diagnostic Degeneracy and the Failure of the Conductive Closure
• Energy release in the solar atmosphere from a stream of infalling prominence debris