The acoustic cut-off frequency of the Sun and the solar magnetic activity cycle

Abstract

The acoustic cut-off frequency -the highest frequency for acoustic solar eigenmodes- is an important parameter of the solar atmosphere as it determines the upper boundary of the p-mode resonant cavities. At frequencies beyond this value, acoustic disturbances are no longer trapped but traveling waves. Interference amongst them give rise to higher-frequency peaks -the pseudomodes- in the solar acoustic spectrum. The pseudomodes are shifted slightly in frequency with respect to p modes making possible the use of pseudomodes to determine the acoustic cut-off frequency. Using data from GOLF and VIRGO instruments on board the SOHO spacecraft, we calculate the acoustic cut-off frequency using the coherence function between both the velocity and intensity sets of data. By using data gathered by these instruments during the entire lifetime of the mission (1996 till the present), a variation in the acoustic cut-off frequency with the solar magnetic activity cycle is found.

Paper accepted in ApJ. 26 Pages, 9 figures

References in corpus (4)

• CoRoT reveals a magnetic activity cycle in a Sun-like star
• The underlying physical meaning of the ${\nu }_{\max }-{\nu }_{\mathrm{c}}$ relation
• Accurate p-mode measurements of the G0V metal-rich CoRoT target HD 52265
• Global p-mode oscillations throughout the complete solar cycle 23 and the beginning of cycle 24

Cited by in corpus (16)

• Gap interpolation by inpainting methods : Application to Ground and Space-based Asteroseismic data
• Surface-effect corrections for oscillation frequencies of evolved stars
• Vertical Propagation of Acoustic Waves in the Solar Inter-Network as Observed by IRIS
• Testing the intrinsic scatter of the asteroseismic scaling relations with Kepler red giants
• Numerical determination of the cutoff frequency in solar models
• Six new rapidly oscillating Ap stars in the Kepler long-cadence data using super-Nyquist asteroseismology
• Solar cycle variation of ${\nu }_{\max }$ in helioseismic data and its implications for asteroseismology
• Observed local dispersion relations for magneto-acoustic-gravity waves in the Sun's atmosphere: Mapping the acoustic cut-off frequency
• Parametrizing the time-variation of the "surface term" of stellar p-mode frequencies: application to helioseismic data
• Variation of acoustic cutoff period with height in the solar atmosphere: theory versus observations
• MOST observations of the Herbig Ae δ-Scuti star HD 34282
• Analysis of the acoustic cut-off frequency and HIPs in six Kepler stars with stochastically excited pulsations
• A Multi-Instrument Investigation of the Frequency Stability of Oscillations Above the Acoustic Cut-Off Frequency with Solar Activity
• Environmental effects on halo abundance and weak lensing peak statistics toward large underdense regions
• HD 42659: The only known roAp star in a spectroscopic binary observed with B photometry, TESS and SALT
• Seismology of active stars