Transverse coronal loop oscillations seen in unprecedented detail by AIA/SDO

White, R. S.; Verwichte, E.

doi:10.1051/0004-6361/201118093

Cited by 103 publications

(83 citation statements)

References 45 publications

(68 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The AIA has seven extreme ultraviolet (EUV) bandpasses (Fe XVIII (94 Å) Nakariakov et al 1999;Aschwanden et al 1999Aschwanden et al , 2002Aschwanden & Schrijver 2011;Wang & Solanki 2004;Hori et al 2005Hori et al , 2007Verwichte et al 2009Verwichte et al , 2010McIntosh et al 2011;Mrozek 2011;White & Verwichte 2012;Wang et al 2012) can be either vertically or horizontally polarised and are interpreted as the magneto-hydrodynamic kink mode (Edwin & Roberts 1983;Nakariakov et al 1999;Goossens et al 2009) observed in the corona as the perturbation of the axis of density enhanced loops. To date, there have been few observations of TLOs displaying higher harmonics.…”

Section: Introductionmentioning

confidence: 99%

“…AIA/SDO provides new insights into coronal phenomena by increasing both the time and spatial resolutions. As coronal features such as TLOs are studied in ever greater detail (White & Verwichte 2012), signatures of higher harmonics may become easier to observe. The SDO may also provide further opportunities to study the exact nature of oscillations in hot coronal loops.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

First observation of a transverse vertical oscillation during the formation of a hot post-flare loop

White

Verwichte

Foullon

2012

A&A

Self Cite

View full text Add to dashboard Cite

Aims. We report and analyse the first observation of a transverse oscillation in a hot coronal loop with the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO), following a linked coronal-flare mass-ejection event on the 3 November 2010. The oscillating coronal loop is observed off the east solar limb and exclusively in the 131 Å and 94 Å bandpasses, indicating a loop plasma of temperature in the range of 9-11 MK. Furthermore, the loop is not observed to cool into the other AIA channels, but just disappears from all bandpasses at the end of the oscillation. Methods. A time series analysis of the loop oscillation is conducted by taking several cuts at different positions along the loop, estimating the transverse displacements over time for two strands in the loop and fitting those with a damped cosine curve. Intensity time variations, both along the loop and for a series of cut cross-sections, are investigated. Using a three-dimensional loop geometry obtained from a comparison of STEREO-B/EUVI and AIA images, we model different modes of transverse oscillations in the uniformly filled loop. Results. Our time series analysis reveals a period of 302 ± 14 s (291 ± 9 s) and a damping time of 306 ± 43 s (487 ± 125 s) for the first (second) loop strand. A spatial phase shift along the loop of approximately 180 • suggests that we observe a higher order harmonic. Intensity oscillations are consistent with an interpretation in terms of a vertically polarised mode. Our forward modelling suggests that the loop oscillates as either a second or third order harmonic of this mode. Conclusions. This is the first observation of a transverse loop oscillation observed exclusively in the hot coronal lines. The loop oscillation is vertically polarised and is dominated by a higher order harmonic mode. We conclude that the excitation mechanism of this 5 min period oscillation is directly connected with the reconnection processes that form the post flare loop, which differs from the blast wave excitation mechanism often proposed as the cause of cooler transverse loop oscillations.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

First observation of a transverse vertical oscillation during the formation of a hot post-flare loop

White

Verwichte

Foullon

2012

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…For example, standing kink oscillations of coronal loops have been used to infer the coronal magnetic field strength (e.g. Nakariakov et al 1999;Nakariakov & Ofman 2001;White & Verwichte 2012) and it has been demonstrated that seismological inversions are consistent with values obtained by magnetic extrapolation and spectral observations (Verwichte et al 2013a). Magnetohydrodynamic waves might also have a significant role in the processes of coronal heating and solar wind acceleration (e.g.…”

Section: Introductionmentioning

confidence: 92%

Excitation and damping of broadband kink waves in the solar corona

Pascoe

Wright

Moortel

et al. 2015

A&A

View full text Add to dashboard Cite

Context. Observations such as those by the Coronal Multi-Channel Polarimeter (CoMP) have revealed that broadband kink oscillations are ubiquitous in the solar corona. Aims. We consider footpoint-driven kink waves propagating in a low β coronal plasma with a cylindrical density structure. We investigate the excitation and damping of propagating kink waves by a broadband driver, including the effects of different spatial profiles for the driver. Methods. We employ a general spatial damping profile in which the initial stage of the damping envelope is approximated by a Gaussian profile and the asymptotic state by an exponential one. We develop a method of accounting for the presence of these different damping regimes and test it using data from numerical simulations. Results. Strongly damped oscillations in low density coronal loops are more accurately described by a Gaussian spatial damping profile than an exponential profile. The consequences for coronal seismology are investigated and applied to observational data for the ubiquitous broadband waves observed by CoMP. Current data cannot distinguish between the exponential and Gaussian profiles because of the levels of noise. We demonstrate the importance of the spatial profile of the driver on the resulting damping profile. Furthermore, we show that a small-scale turbulent driver is inefficient at exciting propagating kink waves.

show abstract

“…The dashed lines show the background trend, which is assumed to be a polynomial. For example White & Verwichte (2012) use a third order polynomial for the background, while Aschwanden et al (2002) contains examples of polynomial trends with order 1-6. The solid blue curves represent the fitted oscillation with two spectral components, described below.…”

Section: Fitting Standing Kink Mode Harmonicsmentioning

confidence: 99%

“…Kink oscillations are typically detected as strongly damped transverse displacements of coronal loops following eruptive or flare events detected using EUV imaging instruments. The quality and detail of these observations have improved (e.g Aschwanden & Schrijver 2011;White & Verwichte 2012) following the launch of the Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA; Lemen et al 2012). More recently, AIA data has been exploited for systematic statistical studies of decaying kink oscillations, which include a catalogue and study of their excitation mechanism (Zimovets & Nakariakov 2015).…”

Section: Introductionmentioning

confidence: 99%

Spatially resolved observation of the fundamental and second harmonic standing kink modes using SDO/AIA

Pascoe

Goddard

Nakariakov

2016

A&A

View full text Add to dashboard Cite

Aims. We consider a coronal loop kink oscillation observed by the Atmospheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO) which demonstrates two strong spectral components. The period of the lower frequency component being approximately twice that of the shorter frequency component suggests the presence of harmonics. Methods. We examine the presence of two longitudinal harmonics by investigating the spatial dependence of the loop oscillation. The time-dependent displacement of the loop is measured at 15 locations along the loop axis. For each position the detrended displacement is fitted as the sum of two damped sinusoids, having periods P 1 and P 2 , and a damping time τ. The shorter period component exhibits anti-phase oscillations in the loop legs. Results. We interpret the observation in terms of the first (global or fundamental) and second longitudinal harmonics of the standing kink mode. The strong excitation of the second harmonic appears connected to the preceding coronal mass ejection (CME) which displaced one of the loop legs. The oscillation parameters found are P 1 " 5.00˘0.62 minutes, P 2 " 2.20˘0.23 minutes, P 1 {2P 2 " 1.15˘0.22, and τ{P " 3.35˘1.45.

show abstract

Transverse coronal loop oscillations seen in unprecedented detail by AIA/SDO

Cited by 103 publications

References 45 publications

First observation of a transverse vertical oscillation during the formation of a hot post-flare loop

First observation of a transverse vertical oscillation during the formation of a hot post-flare loop

Excitation and damping of broadband kink waves in the solar corona

Spatially resolved observation of the fundamental and second harmonic standing kink modes using SDO/AIA

Contact Info

Product

Resources

About