Coronal wave associated with a non-radial filament eruption observed by the Solar Dynamics Observatory

R Zheng,J Yang,Y Jiang,R Erdélyi

doi:10.1093/mnras/stu1361

Abstract

We analyse a coronal wave that occurred during a non-radial filament eruption observed by the Solar Dynamics Observatory on 2011 August 10. The filament underwent an extended time activation phase followed by an abrupt ejection, and during its evolution it rotated towards the south. The eruption was accompanied by fast-wave and slow-perturbation phenomena. The slow perturbation occurred before the eruption and impulsively accelerated almost simultaneously with the eruption; its final propagation velocity was about 300 km s(-1), approximately equal tothat of the associated coronal mass ejection. The slow perturbation is possibly an indicator of an expanding loop overlying the filament. The fast wave was probably caused by the rapid inflation of the overlying loop. Because of the eruption location close to the limb and the effect of the complex environment, the fast coronal wave showed different characteristics in different directions: the kick-off speed was about 430-480 km s(-1), showing deceleration in some directions, and a high speed of up to 782 +/- 21 km s(-1) in another direction. All the results indicate that the coronal wave was a fast-mode magnetohydrodynamic wave, and the wavelet analysis confirms the periodic wave nature of the coronal wave.

Highlights

Propagating global coronal waves, often referred to as extreme ultraviolet (EUV) waves, were originally referred to as ‘EIT waves’, owing to the fact that they were first observed with the EUV Imaging Telescope (EIT; Delaboudiniere et al 1995) onboard the Solar and Heliospheric Observatory (SOHO) spacecraft (e.g. Moses et al 1997; Thompson et al 1998)
The eruption region is outlined by the box, and there is a coronal hole (CH) in the south-west indicated by the white arrow
Note the angle at the north upper turning between the top and the northern part of the filament: it was clearly changed from an acute angle to an obtuse one during the eruption, which confirms that the filament was dragged towards the south during the ascent

Summary

INTRODUCTION

Propagating global coronal waves, often referred to as extreme ultraviolet (EUV) waves, were originally referred to as ‘EIT waves’, owing to the fact that they were first observed with the EUV Imaging Telescope (EIT; Delaboudiniere et al 1995) onboard the Solar and Heliospheric Observatory (SOHO) spacecraft (e.g. Moses et al 1997; Thompson et al 1998). Coronal waves usually appear as propagating diffuse bright fronts in EUV images, with phase speeds of several hundred kilometres per second (Thompson & Myers 2009). They generally emanate from flaring and eruptive active regions (ARs). Thompson et al 1999; Wang 2000; Wu et al 2001; Ofman & Thompson 2002; Ballai, Erdelyi & Pinter 2005; Long et al 2008; Gopalswamy et al 2009; Veronig et al 2010) that were the coronal counterparts of Hα Moreton waves (Moreton 1960) Because such a fast-mode wave model cannot account for all the observed characteristics of coronal waves, several alternative models have been suggested, for.

O B S E RVAT IONSAND DATA A N A LY S I S

Non-radial filament eruption

Coronal wave

Coronal mass ejection

DISCUSSION AND CONCLUSIONS