skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: EXTREME-ULTRAVIOLET OBSERVATIONAL CONSEQUENCES OF THE SPATIAL LOCALIZATION OF NANOFLARE HEATING WITHIN A MULTISTRANDED ATMOSPHERIC LOOP

Journal Article · · Astrophysical Journal

Determining the preferred spatial location of the energy input to solar coronal loops would be an important step forward toward a more complete understanding of the coronal heating problem. Following from the 2008 paper of Sarkar and Walsh, this paper presents a short (10{sup 9} cm {identical_to}10 Mm) 'global loop' as 125 individual strands, where each strand is modeled 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 {approx}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 do demonstrate a possible observable difference. Subsequently, the simulated output is folded through the Transition Region and Coronal Explorer (TRACE) instrument response functions and a rederivation of the temperature using different filter ratio techniques is performed. Given the multithermal 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.

OSTI ID:
21333741
Journal Information:
Astrophysical Journal, Vol. 699, Issue 2; Other Information: DOI: 10.1088/0004-637X/699/2/1480; Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English