Why coronal loops cannot exist without solar gravity

Abstract

view Abstract Citations (15) References (12) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Why Coronal Loops Cannot Exist without Solar Gravity Craig, I. J. D. ; McClymont, A. N. Abstract The authors develop a simple stability analysis of coronal loops which demonstrates that a loop is unstable to coronal temperature fluctuations unless a sufficiently large pressure perturbation accompanies the disturbance. Such pressure fluctuations are possible only if the chromospheric footpoints of the loop exhibit the property of dynamical stiffness, preventing the corona from expanding under the influence of a temperature increase. The stiffness of the chromosphere is shown to derive from its gravitational stratification and its "spring constant" to depend on the gravitational scale height. Any loop whose coronal length is large compared to the chromospheric scale height must therefore "see" the chromospheric footprints as essentially rigid. Publication: The Astrophysical Journal Pub Date: July 1987 DOI: 10.1086/165378 Bibcode: 1987ApJ...318..421C Keywords: Chromosphere; Coronal Loops; Solar Gravitation; Stellar Models; Dynamic Models; Gravitational Effects; Magnetohydrodynamic Stability; Thermal Stability; Solar Physics; GRAVITATION; HYDROMAGNETICS; SUN: CORONA full text sources ADS |