EUV Observational consequences of the spatial localisation of nanoflare heating within a multi-stranded atmospheric loop

Abstract

Determining the preferred spatial location of the energy input to solar coronal loops would be an important step forward towards a more complete understanding of the coronal heating problem. Following on from Sarkar & Walsh (2008) this paper presents a short 10e9 cm "global loop" as 125 individual strands, where each strand is modelled independently by a one-dimensional hydrodynamic simulation. The strands undergo small-scale episodic heating and are coupled together through the frequency distribution of the total energy input to the loop which follows a power law distribution with index ~ 2.29. The spatial preference of the swarm of heating events from apex to footpoint is investigated. From a theoretical perspective, the resulting emission measure weighted temperature profiles along these two extreme cases does demonstrate a possible observable difference. Subsequently, the simulated output is folded through the TRACE instrument response functions and a re-derivation of the temperature using different filter-ratio techniques is performed. Given the multi-thermal scenario created by this many strand loop model, a broad differential emission measure results; the subsequent double and triple filter ratios are very similar to those obtained from observations. However, any potential observational signature to differentiate between apex and footpoint dominant heating is possibly below instrumental thresholds. The consequences of using a broadband instrument like TRACE and Hinode-XRT in this way are discussed.

arXiv commentAstrophysical Journal (Accepted)

References in corpus (4)

• Multi-Thread Hydrodynamic Modeling of a Solar Flare
• Active region transition region loop populations and their relationship to the corona
• More on the determination of the coronal heating function from Yohkoh data
• Hydrodynamic Simulation of a nano-flare heated multi-strand solar atmospheric loop

Cited by in corpus (7)

• Is the High-Resolution Coronal Imager Resolving Coronal Strands? Results from AR 12712
• Statistical Signatures of Nanoflare Activity. I. Monte Carlo Simulations and Parameter-space Exploration
• Observation and Modeling of Chromospheric Evaporation in a Coronal Loop Related to Active Region Transient Brightening
• Modeling solar coronal bright point oscillations with multiple nanoflare heated loops
• Statistical Signatures of Nanoflare Activity. II. A Nanoflare Explanation for Periodic Brightenings in Flare Stars observed by NGTS
• Multi-Stranded Coronal Loops: Quantifying Strand Number and Heating Frequency from Simulated Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) Observations
• Multi-strand coronal loop model and filter-ratio analysis