Signatures of impulsive localized heating in the temperature distribution of multi-stranded coronal loops

Abstract

We study the signatures of different coronal heating regimes on the differential emission measure (DEM) of multi-stranded coronal loops by means of hydrodynamic simulations. We consider heating either uniformly distributed along the loops or localized close to the chromospheric footpoints, in both steady and impulsive conditions. Our simulations show that condensation at the top of the loop forms when the localized heating is impulsive with a pulse cadence time shorter than the plasma cooling time, and the pulse energy is below a certain threshold. A condensation does not produce observable signatures in the global DEM structure. Conversely, the DEM coronal peak is found sensitive to the pulse cadence time. Our simulations can also give an explanation of the warm overdense and hot underdense loops observed by TRACE, SOHO and Yohkoh. However, they are unable to reproduce both the transition region and the coronal DEM structure with a unique set of parameters, which outlines the need for a more realistic description of the transition region.

31 pages, 7 figures

References in corpus (4)

• Highly Efficient Modeling of Dynamic Coronal Loops
• Are Coronal Loops Isothermal or Multithermal? Yes!
• Estimating the Chromospheric Absorption of Transition Region Moss Emission
• An explanation of the solar transition region

Cited by in corpus (22)

• Solar science with the Atacama Large Millimeter/submillimeter Array - A new view of our Sun
• The multi-thermal and multi-stranded nature of coronal rain
• Using a Differential Emission Measure and Density Measurements in an Active Region Core to Test a Steady Heating Model
• Can Thermal Nonequilibrium Explain Coronal Loops?
• Non-Equilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind \textit{(Invited Review)}
• On the occurrence of thermal non-equilibrium in coronal loops
• On the Accuracy of the Differential Emission Measure Diagnostics of Solar Plasmas. Application to AIA/SDO. Part II: Multithermal plasmas
• 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
• Observing the formation of flare-driven coronal rain
• The effects of numerical resolution, heating timescales and background heating on thermal non-equilibrium in coronal loops
• Diagnosing the time-dependence of active region core heating from the emission measure: II. Nanoflare trains
• Plasma parameters and geometry of cool and warm active region loops
• Self-consistent 3D radiative MHD simulations of coronal rain formation and evolution
• The role of asymmetries in coronal rain formation during thermal non-equilibrium cycles
• EUV fine structure and variability associated with coronal rain revealed by Solar Orbiter/EUI HRIEUV and SPICE
• EUV Emission and Scattered Light Diagnostics of Equatorial Coronal Holes as Seen by Hinode/EIS
• Solar low-lying cool loops and their contribution to the transition region EUV output
• Implications of spicule activity on coronal loop heating and catastrophic cooling
• Modeling of Condensations in Coronal Loops Produced by Impulsive Heating
• Modelling solar low-lying cool loops with optically thick radiative losses
• Helical flows along coronal loops following the launch of a coronal mass ejection