EUV sprays : jet-like eruptive activity on the solar limb

Harrison, R. A. and Bryans, P. and Bingham, R. (2001) EUV sprays : jet-like eruptive activity on the solar limb. Astronomy and Astrophysics, 379 (1). pp. 324-335. ISSN 0004-6361

Full text not available in this repository.Request a copy from the Strathclyde author

Abstract

Jet-like eruptive events have been detected in the extreme ultraviolet (EUV) observations from the Solar and Heliospheric Observatory (SOHO) spacecraft. Some jet-like events are shown and for one event, that of January 22 2000, we provide a detailed analysis of the EUV observations. The January 22 observation was part of an on-going campaign to observe the onset of coronal mass ejections (CMEs) using extreme ultraviolet spectroscopy. A high-temperature fan-like jet was first detected in emission lines from plasmas at one million K and over, and it appears to be the onset of a narrow mass ejection identified later in coronagraph data. This was followed by a dramatic jet or finger of cool ($\le$250 000 K), rotating plasma which extended vertically, high into the corona. It extended well beyond the field of view of the instrument and appears to relate to a small ejected cloud which is detected in subsequent coronagraph data. The spectroscopic characteristics are used to provide plasma diagnostic information for these two events, and this combined with images for a wide range of temperatures allows a thorough investigation of the processes leading to such eruptions. A simple accreting magnetic field model is used to descibe the basic features of the jet activity.