Diagnostic of the temperature and differential emission measure (DEM) based on &amp;lt;I&amp;gt;Hinode&amp;lt;/I&amp;gt;/XRT data

Siarkowski, M.; Falewicz, R.; Kȩpa, A.; Rudawy, P.

doi:10.5194/angeo-26-2999-2008

Cited by 9 publications

(12 citation statements)

References 14 publications

(22 reference statements)

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“…It was compared to other methods for the calculation of DEM (e.g., Siarkowski et al 2008;Fludra & Sylwester 1986) and applied on solar data (e.g., Sylwester et al 2010). The (n + 1)th approximation of a DEM model is given by…”

Section: Differential Emission Measure Analysismentioning

confidence: 99%

“…The differential emission measure (DEM) indicates the amount of emission from plasmas at a specific temperature. As such, it can reflect the properties, such as the coronal heating mechanism, and was intensively investigated for variety of solar structures and events (e.g., Del Zanna 2013b; Del Schmelz et al 2013Schmelz et al , 2011bSchmelz et al ,a, 2009Hannah & Kontar 2012;Winebarger et al 2012;O'Dwyer et al 2011;Brooks et al 2012Brooks et al , 2011Reale et al 2009;Siarkowski et al 2008;Parenti & Vial 2007;Schmelz & Martens 2006;Lanzafame et al 2005Lanzafame et al , 2002Judge et al 1997;Thompson 1990;Fludra & Sylwester 1986;Sylwester et al 1980;Craig 1977;Craig & Brown 1976). The properties of emission in the core of an active region have been studied by Warren et al (2011), Tripathi et al (2011), and Viall & Klimchuk (2011, and typically found to be multithermal.…”

Section: Introductionmentioning

confidence: 99%

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Differential emission measure analysis of active region cores and quiet Sun for the non-Maxwellianκ-distributions

Mackovjak

Dzifčáková

Dudík

2014

A&A

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Context. The non-Maxwellian κ-distributions have been detected in the solar wind and can explain intensities of some transition region lines. Presence of such distributions in the outer layers of the solar atmosphere influences the ionization and excitation equilibrium and widens the line contribution functions. This behavior may be reflected on the reconstructed differential emission measure (DEM). Aims. We aim to investigate the influence of κ-distributions on the reconstructed DEMs. Methods. We perform DEM reconstruction for three active region cores and a quiet Sun region using the Withbroe-Sylwester method and the regularization method. Results. We find that the reconstructed DEMs depend on the value of κ. The DEMs of the active region cores show similar behavior with decreasing κ, or an increasing departure from the Maxwellian distribution. For lower κ, the peaks of the DEMs are typically shifted to higher temperatures and the DEMs themselves become more concave. This is caused by the less steep high-temperature slopes for lower κ. However, the low-temperature slopes do not change significantly even for extremely low κ. The behavior of the quiet-Sun DEM distribution is different. It becomes progressively less multithermal for lower κ with the EM-loci plots that indicate near-isothermal plasma for κ = 2. Conclusions. The κ-distributions can influence the reconstructed DEMs. The slopes of the DEM, however, do not change with κ significantly enough to produce different constraints on the heating mechanism in terms of frequency of coronal heating events.

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Section: Differential Emission Measure Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Differential emission measure analysis of active region cores and quiet Sun for the non-Maxwellianκ-distributions

Mackovjak

Dzifčáková

Dudík

2014

A&A

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“…where I i is an experimental flux in the channel i, G i (T ) is the temperature response function of the channel i, DEM (T ) is the differential emission measure, and T is the temperature. The genetic algorithm solves this problem by mimicking the process of the natural selection (Siarkowski et al, 2008;Shestov, Reva, and Kuzin, 2014). It works in the following way:…”

Section: Resultsmentioning

confidence: 99%

Estimate of the Upper Limit on Hot Plasma Differential Emission Measure (DEM) in Non-Flaring Active Regions and Nanoflare Frequency Based on the Mg xii Spectroheliograph Data from CORONAS-F/SPIRIT

et al. 2018

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The nanoflare-heating theory predicts steady hot plasma emission in the non-flaring active regions. It is hard to find this emission with conventional non-monochromatic imagers (such as Atmospheric Imaging Assembly or X-Ray Telescope), because their images contain a cool temperature background. In this work, we search for hot plasma in non-flaring active regions using the Mg xii spectroheliograph onboard Complex Orbital Observations Near-Earth of Activity on the Sun (CORONAS)-F/SPectroheliographIc X-ray Imaging Telescope (SPIRIT). This instrument acquired monochromatic images of the solar corona in the Mg xii 8.42Å line, which emits only at temperatures higher than 4 MK. The Mg xii images contain the signal only from hot plasma without any lowtemperature background. We studied the hot plasma in active regions using the SPIRIT data from 18 -28 February 2002. During this period, the Mg xii spectroheliograph worked with a 105-second cadence almost without data gaps. The hot plasma was observed only in the flaring active regions. We do not observe any hot plasma in non-flaring active regions. The hot plasma column emission measure in the non-flaring active region should not exceed 3 × 10 24 cm −5 . The hot Differential Emission Measure (DEM) is less than 0.01 % of the DEM of the main temperature component. Absence of Mg xii emission in the non-flaring active regions can be explained by weak and frequent nanoflares (delay less than 500 seconds) or by very short and intense nanoflares that lead to non-equilibrium ionization.

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“…For the DEM reconstruction we used a Genetic Algorithm (GA) (Siarkowski et al 2008). The algorithm is based on ideas of biological evolution and natural selection.…”

Section: Interpretation Of the Spirit Spectroheliogramsmentioning

confidence: 99%

Extreme Ultraviolet Spectra of Solar Flares From the Extreme Ultraviolet Spectroheliograph Spirit Onboard the Coronas-F Satellite

Shestov¹,

Reva²,

Kuzin³

2013

ApJ

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We present detailed EUV spectra of 4 large solar flares: M5.6, X1.3, X3.4, and X17 classes in the spectral ranges 176-207Å and 280-330Å. These spectra were obtained by the slitless spectroheliograph SPIRIT aboard the CORONAS-F satellite. To our knowledge these are the first detailed EUV spectra of large flares obtained with spectral resolution of ∼ 0.1Å. We performed a comprehensive analysis of the obtained spectra and provide identification of the observed spectral lines. The identification was performed based on the calculation of synthetic spectra (CHIANTI database was used), with simultaneous calculations of DEM and density of the emitting plasma. More than 50 intense lines are present in the spectra that correspond to a temperature range of T = 0.5 − 16 MK; most of the lines belong to Fe, Ni, Ca, Mg, Si ions. In all the considered flares intense hot lines from Ca XVII, Ca XVIII, Fe XX, Fe XXII, and Fe XXIV are observed. The calculated DEMs have a peak at T ∼ 10 MK. The densities were determined using Fe XI-Fe XIII lines and averaged 6.5 × 10 9 cm −3 . We also discuss the identification, accuracy and major discrepancies of the spectral line intensity prediction. Subject headings: Sun: activity -Sun: flare -Sun: UV radiation 280 290 300 310 320 330 λ, A 0.000 0.001 0.002 0.003 0.004 0.005 Intensity, erg/cm2/s/A

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Diagnostic of the temperature and differential emission measure (DEM) based on <I>Hinode</I>/XRT data

Cited by 9 publications

References 14 publications

Differential emission measure analysis of active region cores and quiet Sun for the non-Maxwellianκ-distributions

Differential emission measure analysis of active region cores and quiet Sun for the non-Maxwellianκ-distributions

Estimate of the Upper Limit on Hot Plasma Differential Emission Measure (DEM) in Non-Flaring Active Regions and Nanoflare Frequency Based on the Mg xii Spectroheliograph Data from CORONAS-F/SPIRIT

Extreme Ultraviolet Spectra of Solar Flares From the Extreme Ultraviolet Spectroheliograph Spirit Onboard the Coronas-F Satellite

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