PUTTING CORONAL SEISMOLOGY ESTIMATES OF THE MAGNETIC FIELD STRENGTH TO THE TEST

Journal Article · Fri Jul 10 04:00:00 EDT 2009 · Astrophysical Journal (Online)

DOI:https://doi.org/10.1088/0004-637X/699/2/L72; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21313052

De Moortel, I; Pascoe, D J ^[1]

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1. School of Mathematics and Statistics, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom)

The magnetic field strength inside a model coronal loop is 'estimated' using coronal seismology, to examine the reliability of magnetic field strengths derived from observed, transverse coronal loop oscillations. Three-dimensional numerical simulations of the interaction of an external pressure pulse with a coronal loop (modeled as a three-dimensional density enhancement inside a two-dimensional magnetic arcade) are analyzed and the 'observed' properties of the excited transverse loop oscillations are used to derive the value of the local magnetic field strength, following the method of Nakariakov and Ofman. Due to the (unexpected) change in periodicity, the magnetic field derived from our 'observed' oscillation is substantially different from the actual (input) magnetic field value (approximately 50%). Coronal seismology can derive useful information about the local magnetic field, but the combined effect of the loop curvature, the density ratio, and aspect ratio of the loop appears to be more important than previously expected.

• OSTI ID: 21313052
• Journal Information: Astrophysical Journal (Online), Journal Name: Astrophysical Journal (Online) Journal Issue: 2 Vol. 699; ISSN 1538-4357
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASPECT RATIO
COMPUTERIZED SIMULATION
MAGNETIC FIELDS
OSCILLATIONS
PERIODICITY
PULSES
RELIABILITY
SEISMOLOGY
SUN
THREE-DIMENSIONAL CALCULATIONS
TWO-DIMENSIONAL CALCULATIONS