Do All Candle-Flame-Shaped Flares Have the Same Temperature Distribution?

Gou, Tingyu; Li, Rui; Wang, Yuming

doi:10.1007/s11207-015-0750-8

Cited by 30 publications

(36 citation statements)

References 34 publications

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“…Using Yohkoh/SXT data, Tsuneta (1996) found that a cusp-shaped flare had hot plasma on the outer edges of the cusp, with a channel of cooler, denser plasma down the middle. Gou et al (2015) surveyed many cuspshaped flares using AIA and found that most of them adhered to this pattern. Guidoni et al (2015) study a flare using AIA data and find a similar temperature structure, but without the cooler channel.…”

Section: Introductionmentioning

confidence: 94%

“…Some studies have suggested that integrating only the high temperature component in Equation 1 provides a better characterization of the temperature of the supra-arcade plasma (e.g. Gou et al 2015). However, we elect to integrate over the entire DEM because we are also interested in the temperature of the voids associated with the SADs.…”

Section: Thermal Properties Of Supra-arcade Plasmamentioning

confidence: 99%

“…This assumption is justified because supra-arcade plasma sheets tend to be quite narrow when observed edge on (e.g. Savage et al 2010;Liu 2013;Liu et al 2013;Gou et al 2015), limiting the ability of the plasma to flow in the direction perpendicular to the plasma sheet. The neutral line of the active region that produces this eruption is very close to being aligned with the North-South direction, as can be seen in images from STEREO-A/SECCHI, which was positioned ahead of the Earth with a separation angle of about 105 degrees (see Figure 2 in Savage et al 2012).…”

Section: Heating Terms In the Supra-arcade Regionmentioning

confidence: 99%

“…With the introduction of the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO), many of these plasma sheets have been observed with the 131Å channel (e.g. Reeves & Golub 2011;Warren et al 2011;Savage et al 2012;Liu et al 2013;Hanneman & Reeves 2014;Innes et al 2014;Gou et al 2015;Guidoni et al 2015;Li et al 2016), which is sensitive to plasma at about 10 MK (Boerner et al 2012). …”

Section: Introductionmentioning

confidence: 99%

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An Exploration of Heating Mechanisms in a Supra-arcade Plasma Sheet Formed after a Coronal Mass Ejection

Reeves¹,

Freed²,

McKenzie³

et al. 2017

ApJ

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We perform a detailed analysis of the thermal structure of the region above the post-eruption arcade for a flare that occurred on 2011 October 22. During this event, a sheet of hot plasma is visible above the flare loops in the 131Å bandpass of the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO). Supra-arcade downflows (SADs) are observed traveling sunward through the post-eruption plasma sheet. We calculate differential emission measures using the AIA data and derive an emission measure weighted average temperature in the supra-arcade region. In areas where many SADs occur, the temperature of the supra-arcade plasma tends to increase, while in areas where no SADs are observed, the temperature tends to decrease. We calculate the plane-of-sky velocities in the supra-arcade plasma and use them to calculate the potential heating due to adiabatic compression and viscous heating. Ten of the 13 SADs studied have noticeable signatures in both the adiabatic and the viscous terms. The adiabatic heating due to compression of plasma in front of the SADs is on the order of 0.1 -0.2 MK/s, which is similar in magnitude to the estimated conductive cooling rate. This result supports the notion that SADs contribute locally to the heating of plasma in the supra-arcade region. We also find that in the region without SADs, the plasma cools at a rate slower than the estimated conductive cooling, indicating additional heating mechanisms may act globally to keep the plasma temperature high.

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Section: Introductionmentioning

confidence: 94%

Section: Thermal Properties Of Supra-arcade Plasmamentioning

confidence: 99%

Section: Heating Terms In the Supra-arcade Regionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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An Exploration of Heating Mechanisms in a Supra-arcade Plasma Sheet Formed after a Coronal Mass Ejection

Reeves¹,

Freed²,

McKenzie³

et al. 2017

ApJ

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“…The comparisons of the reconstructions and the observations show that the reconstructions for 94Å and 335Å fit the observations poorly. Previous studies also show that the reconstruction errors at 94Å and 335Å are relatively larger than at other passbands (Hanneman & Reeves 2014;Gou et al 2015). The DEM errors using the spectra (triangle) predicted by CHIANTI 8 and the Feldman abundance are smaller than those using the spectra (diamond) predicted by CHIANTI 7 and the same coronal abundance for the 94Å band, apparently because of the improved atomic rates.…”

Section: Comparison Of the Observations And The Reconstructions From Demmentioning

confidence: 83%

Heating of an Erupting Prominence Associated with a Solar Coronal Mass Ejection on 2012 January 27

Lee

Raymond

Reeves

et al. 2017

ApJ

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We investigate the heating of an erupting prominence and loops associated with a coronal mass ejection and X-class flare. The prominence is seen in absorption in EUV at the beginning of its eruption. Later the prominence changes to emission, which indicates heating of the erupting plasma. We find the densities of the erupting prominence using the absorption properties of hydrogen and helium in different passbands. We estimate the temperatures and densities of the erupting prominence and loops seen as emission features using the differential emission measure method, which uses both EUV and X-ray observations from the Atmospheric Imaging Assembly on board Solar Dynamics Observatory and the X-ray Telescope on board Hinode. We consider synthetic spectra using both photospheric and coronal abundances in these calculations. We verify the methods for the estimation of temperatures and densities for the erupting plasmas. Then we estimate the thermal, kinetic, radiative loss, thermal conduction, and heating energies of the erupting prominence and loops. We find that the heating of the erupting prominence and loop occurs strongly at early times in the eruption. This event shows a writhing motion of the erupting prominence, which may indicate a hot flux rope heated by thermal energy release during magnetic reconnection.

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