Spectroscopic diagnostics of the non-Maxwellian $\kappa$-distributions using SDO/EVE observations of the 2012 March 7 X-class flare

Abstract

Spectroscopic observations made by the Extreme Ultraviolet Variability Experiment (EVE) on board the Solar Dynamics Observatory (SDO) during the 2012 March 7 X5.4-class flare (SOL2012-03-07T00:07) are analyzed for signatures of the non-Maxwellian kappa-distributions. Observed spectra were averaged over 1 minute to increase photon statistics in weaker lines and the pre-flare spectrum was subtracted. Synthetic line intensities for the kappa-distributions are calculated using the KAPPA database. We find strong departures (kappa < 2) during the early and impulsive phases of the flare, with subsequent thermalization of the flare plasma during the gradual phase. If the temperatures are diagnosed from a single line ratio, the results are strongly dependent on the value of kappa. For kappa=2, we find temperatures about a factor of two higher than the commonly used Maxwellian ones. The non-Maxwellian effects could also cause the temperatures diagnosed from line ratios and from the ratio of GOES X-ray channels to be different. Multithermal analysis reveals the plasma to be strongly multithermal at all times with flat DEMs. For lower kappa, the DEM_kappa are shifted towards higher temperatures. The only parameter that is nearly independent of kappa is electron density, where we find log(N_e) $\approx$ 11.5 almost independently of time. We conclude that the non-Maxwellian effects are important and should be taken into account when analyzing solar flare observations, including spectroscopic and imaging ones.

arXiv commentThe Astrophysical Journal, accepted

References in corpus (61)

• The Interface Region Imaging Spectrograph (IRIS)
• Kappa distributions: theory and applications in space plasmas
• Global Energetics of Thirty-Eight Large Solar Eruptive Events
• CHIANTI - An atomic database for Emission Lines. Version 8
• Differential Emission Measures from the Regularized Inversion of Hinode and SDO data
• Implications of X-ray Observations for Electron Acceleration and Propagation in Solar Flares
• Dielectronic recombination data for dynamic finite-density plasmas I. Goals and methodology
• The standard flare model in three dimensions III. Slip-running reconnection properties
• RHESSI Microflare Statistics II. X-ray Imaging, Spectroscopy & Energy Distributions
• Recent Advances in Understanding Particle Acceleration Processes in Solar Flares
• Hot Spine Loops and the Nature of a Late-Phase Solar Flare
• From coronal observations to MHD simulations, the building blocks for 3D models of solar flares
• A Systematic Survey of High Temperature Emission in Solar Active Regions
• Deducing Electron Properties From Hard X-Ray Observations
• Ionization Equilibrium Timescales in Collisional Plasmas
• Impulsive and Long Duration High-Energy Gamma-ray Emission From the Very Bright 2012 March 7 Solar Flares
• The Formation of Kappa-Distribution Accelerated Electron Populations in Solar Flares
• Kappa Distribution Model for Hard X-Ray Coronal Sources of Solar Flares
• Multi-thermal dynamics and energetics of a coronal mass ejection in the low solar atmosphere
• Properties of a solar flare kernel observed by Hinode and SDO
• Formation of Magnetic Flux Ropes during Confined Flaring Well Before the Onset of a Pair of Major Coronal Mass Ejections
• On the Relationship Between a Hot-channel-like Solar Magnetic Flux Rope and its embedded Prominence
• Simultaneous IRIS and Hinode/EIS observations and modelling of the 27 October 2014 X 2.0 class flare
• Microflare Heating of a Solar Active Region Observed with NuSTAR, Hinode/XRT, and SDO/AIA
• Implosion of coronal loops during the impulsive phase of a solar flare
• Correlation of hard X-ray and white light emission in solar flares
• Solar Transition-Region Lines Observed by the Interface Region Imaging Spectrograph: Diagnostics for the O IV and Si IV Lines
• Non-Equilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind \textit{(Invited Review)}
• Kappa distribution and hard X-ray emission of solar flares
• A Statistical Survey of Hard X-ray Spectral Characteristics of Solar Flares with Two Footpoints
• KAPPA: A Package for Synthesis of optically thin spectra for the non-Maxwellian kappa-distributions based on the CHIANTI database
• Chromospheric Evaporation in an M1.8 Flare Observed by the Extreme-ultraviolet Imaging Spectrometer on Hinode
• Non-Maxwellian analysis of the transition-region line profiles observed by the Interface Region Imaging Spectrograph
• H to Zn Ionization Equilibrium for the Non-Maxwellian Electron kappa-distributions: Updated Calculations
• Ion Charge States in the Fast Solar Wind: New Data Analysis and Theoretical Refinements
• Testing EUV/X-ray Atomic Data for the Solar Dynamics Observatory
• The emission measure distribution of impulsive phase flare footpoints
• Observing the formation of flare-driven coronal rain
• Hot Plasma in Non-Flaring Active Regions Observed by the Extreme-ultraviolet Imaging Spectrometer on Hinode
• First evidence of non-Gaussian solar flare EUV spectral line profiles and accelerated non-thermal ion motion
• Time-Dependent Density Diagnostics of Solar Flare Plasmas Using SDO/EVE
• Multiwavelength imaging and spectroscopy of chromospheric evaporation in an M-class solar flare
• Non-Gaussian Velocity Distributions in Solar Flares from Extreme Ultraviolet Lines: A Possible Diagnostic of Ion Acceleration
• Signatures of the non-Maxwellian $\kappa$-distributions in optically thin line spectra \subtitle{I. Theory and synthetic Fe IX--XIII spectra}
• Analysis and modelling of recurrent solar flares observed with Hinode/EIS on March 9, 2012
• A Simple Method for Modeling Collision Processes in Plasmas with a Kappa Energy Distribution
• IRIS, Hinode, SDO, and RHESSI observations of a white light flare produced directly by non-thermal electrons
• NuSTAR hard X-ray observation of a sub-A class solar flare
• Differential emission measure Analysis of a limb solar flare on 2012 July 19
• Multi-thermal representation of the kappa-distribution of solar flare electrons and application to simultaneous X-ray and EUV observations
• The spectroscopic imprint of the pre-eruptive configuration resulting into two major coronal mass ejections
• Electron Distribution Functions in Solar Flares from combined X-ray and EUV Observations
• Imaging and Spectroscopic Observations of a Transient Coronal Loop: Evidence for the Non-Maxwellian $\kappa$-Distributions
• Heating of an erupting prominence associated with a solar coronal mass ejection on 2012 January 27
• Collisionless shocks in partly ionized plasma with cosmic rays: microphysics of non-thermal components
• Doppler speeds of the hydrogen Lyman lines in solar flares from EVE
• Dielectronic Recombination of Argon-Like Ions
• A Statistical Study of Distant Consequences of Large Solar Energetic Events
• Impulsive Heating of Solar Flare Ribbons Above 10 MK
• Expanding and Contracting Coronal Loops as Evidence of Vortex Flows Induced by Solar Eruptions
• Solar Flare Impulsive Phase Emission Observed with SDO/EVE

Cited by in corpus (7)

• Broad Non-Gaussian Fe XXIV Line Profiles in the Impulsive Phase of the 2017 September 10 X8.3 class Flare Observed by Hinode/EIS
• Signatures of the non-Maxwellian $\kappa$-distributions in optically thin line spectra. II. Synthetic Fe XVII--XVIII X-ray coronal spectra and predictions for the Marshall Grazing-Incidence X-ray Spectrometer (MaGIXS)
• X-ray Spectra from Plasmas with High-Energy Electrons: kappa-distributions and e-e Bremsstrahlung
• Solar Flare Irradiance: Observations and Physical Modeling
• Expansion of Hot Plasma into Cold Plasma
• Multi-diagnostic convergence: a single measurement in weakly collisional plasmas
• Plasma Diagnostics From Active Region and Quiet Sun Spectra Observed by Hinode/EIS: Quantifying the Departures from a Maxwellian Distribution