An Investigation of Time Lag Maps Using Three-Dimensional Simulations of Highly Stratified Heating

Winebarger, Amy R.; Lionello, R.; Downs, Cooper; Mikić, Z.; Linker, J. A.; Mok, Y.

doi:10.3847/0004-637x/831/2/172

Cited by 14 publications

(16 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Model A: a 3D hydrodynamic simulation from Predictive Science Inc of a quiescent active region based on the observed magnetic field of NOAA Active Region (AR) 7986 (Mok et al 2005(Mok et al , 2008. The properties of this simulation have been found to agree well with observations (Mok et al 2016;Winebarger et al 2016).…”

Section: Inter-slit Spacingsupporting

confidence: 84%

The Multi-slit Approach to Coronal Spectroscopy with the Multi-slit Solar Explorer (MUSE)

Pontieu¹,

Martínez-Sykora²,

Testa³

et al. 2019

ApJ

Self Cite

View full text Add to dashboard Cite

The Multi-slit Solar Explorer (MUSE) is a proposed mission aimed at understanding the physical mechanisms driving the heating of the solar corona and the eruptions that are at the foundation of space weather. MUSE contains two instruments, a multi-slit EUV spectrograph and a context imager. It will simultaneously obtain EUV spectra (along 37 slits) and context images with the highest resolution in space (0.33-0.4 ) De Pontieu et al. straightforward, as a simultaneous measurement of I(x, y, λ) is always achieved. Detectors for hard X-rays (HXR) provide an energy resolution of a fraction of a keV (Furukawa et al. 2019; Athiray et al. 2017), and a useful resolving power for gamma rays and HXR bremsstrahlung continua, applicable to the very hottest components of the corona, but unfortunately, not for the majority of coronal features that emit EUV. Furthermore, the spatial resolution of state-of-the-art X-ray telescopes (Buitrago-Casas et al. 2017; Chan et al. 2018) is not sufficient to resolve the cross-sectional profiles of bright coronal loops, or their footpoints, where the majority of HXR emission is produced. For soft X-rays (SXR), Bandler et al. (2019) recently demonstrated transition-edge-sensor-based microcalorimeter arrays that provide an energy resolution of 2 eV over the energy range 0.2-7 keV, and thus a resolving power of 3, 500 at 7 keV, but dropping to 100 at ∼ 200eV (∼ 60Å). The count rates for such microcalorimeter systems are limited, and the achievable dynamic range, currently, compromises the utility of such systems for solar observations. Options 2 and 3 can be implemented in a variety of ways, some of which require a sequence of multiple measurements to obtain a single "snapshot" of I(x, y, λ). Analysis of such data is straightforward when the time scales of the process under study are longer than the cycle time of the sequence. Narrow passband filters to implement option 2 are employed at visible, infrared (IR) and radio-frequency (RF) wavelengths, including the measurement of I for multiple polarization states in order to perform spectropolarimetric inversions using visible and near-infrared (NIR) line emission (e.g., Scharmer et al. 2008), and microwave and RF observations of gyroresonance emission, which in combination with high resolution EUV observations can provide valuable diagnostics of the 3D structure of the coronal magnetic field (e.g., Brosius et al. 2002) and electron beams generated in flares and jets (e.g. Chen et al. 2013). Owing ultimately to the low reflectance and transmittance of materials for EUV wavelengths, the achievable resolving power of EUV multilayer coatings for option 2 is only around 10 to 30. A spectrograph, option 3, therefore provides the best resolving power in the EUV.In a traditional imaging spectrograph, light passes through a single entrance slit and is dispersed and re-imaged onto the focal plane. This preserves spatial information in the direction perpendicular

show abstract

Section: Inter-slit Spacingsupporting

confidence: 84%

The Multi-slit Approach to Coronal Spectroscopy with the Multi-slit Solar Explorer (MUSE)

Pontieu¹,

Martínez-Sykora²,

Testa³

et al. 2019

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…Warren et al 2002;Ugarte-Urra et al 2006Viall & Klimchuk 2011, 2017 and can be both explained so far by uniformly distributed heating models (e.g Viall & Klimchuk 2013;Bradshaw & Viall 2016) as well as TNE models (e.g. Lionello et al 2016;Winebarger et al 2016;Froment et al 2017). This is also clearly the case for the observations we analyse in this paper (see Sect.…”

Section: Cooling Signatures From Time-lag Mapssupporting

confidence: 71%

Multi-scale observations of thermal non-equilibrium cycles in coronal loops

Froment

Antolin

Henriques

et al. 2019

A&A

View full text Add to dashboard Cite

Context. Thermal non-equilibrium (TNE) is a phenomenon that can occur in solar coronal loops when the heating is quasi-constant and highly-stratified. Under such heating conditions, coronal loops undergo cycles of evaporation and condensation. The recent observations of ubiquitous long-period intensity pulsations in coronal loops and their relationship with coronal rain have demonstrated that understanding the characteristics of TNE cycles is an essential step in constraining the circulation of mass and energy in the corona. Aims. We report unique observations with the Solar Dynamics Observatory (SDO) and the Swedish 1-m Solar Telescope (SST) that link the captured thermal properties across the extreme spatiotemporal scales covered by TNE processes. Methods. Within the same coronal loop bundle, we captured 6 hr period coronal intensity pulsations in SDO/AIA and coronal rain observed off-limb in the chromospheric Hα and Ca II K spectral lines with SST/CRISP and SST/CHROMIS. We combined a multithermal analysis of the cycles with AIA and an extensive spectral characterisation of the rain clumps with the SST. Results. We find clear evidence of evaporation-condensation cycles in the corona which are linked with periodic coronal rain showers. The high-resolution spectroscopic instruments at the SST reveal the fine-structured rain strands and allow us to probe the cooling phase of one of the cycles down to chromospheric temperatures. Conclusions. These observations reinforce the link between long-period intensity pulsations and coronal rain. They also demonstrate the capability of TNE to shape the dynamics of active regions on the large scales as well as on the smallest scales currently resolvable.

show abstract

“…This was termed "incomplete condensation." Whether solutions of this type are consistent with all the observed properties of coronal loops has yet to be established Winebarger et al 2014Winebarger et al , 2016Winebarger et al , 2018.…”

Section: Introductionmentioning

confidence: 98%

The Role of Asymmetries in Thermal Nonequilibrium

Klimchuk

Luna

2019

ApJ

View full text Add to dashboard Cite

Thermal non-equilibrium (TNE) is a fascinating situation that occurs in coronal magnetic flux tubes (loops) for which no solution to the steady-state fluid equations exists. The plasma is constantly evolving even though the heating that produces the hot temperatures does not. This is a promising explanation for isolated phenomena such as prominences, coronal rain, and longperiod pulsating loops, but it may also have much broader relevance. As known for some time, TNE requires that the heating be both (quasi) steady and concentrated at low coronal altitudes.Recent studies indicate that asymmetries are also important, with large enough asymmetries in the heating and/or cross-sectional area resulting in steady flow rather than TNE. Using reasonable approximations, we have derived two formulae for quantifying the conditions necessary for TNE. As a rough rule of thumb, the ratio of apex to footpoint heating rates must be less than about 0.1, and asymmetries must be less than about a factor of 3. The precise values are case dependent. We have tested our formulae with 1D hydrodynamic loop simulations and find a very acceptable agreement. These results are important for developing physical insight about TNE and assessing how widespread it may be on the Sun.

show abstract

An Investigation of Time Lag Maps Using Three-Dimensional Simulations of Highly Stratified Heating

Cited by 14 publications

References 32 publications

The Multi-slit Approach to Coronal Spectroscopy with the Multi-slit Solar Explorer (MUSE)

The Multi-slit Approach to Coronal Spectroscopy with the Multi-slit Solar Explorer (MUSE)

Multi-scale observations of thermal non-equilibrium cycles in coronal loops

The Role of Asymmetries in Thermal Nonequilibrium

Contact Info

Product

Resources

About