Astron. Astrophys. 361, 759-765 (2000)

An H surge and X-ray jet - Magnetic properties and velocity patterns

J. Zhang ^1,2, J. Wang ^1,2 and Y. Liu <sup>1

1</sup> Beijing Astronomical Observatory, Chinese Academy of Sciences, Beijing 100012, P.R. China (zjun@ourstar.bao.ac.cn; wjx@ourstar.bao.ac.cn)
² National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, P.R. China

Received 12 May 2000 / Accepted 19 July 2000

Abstract

We described simultaneous observations of a surge in H and an X-ray jet in NOAA 8100 on November 1, 1997. We found that the H surge was spatially coincident with the X-ray jet. They occurred at the site where the pre-existing magnetic flux was "cancelled" by a newly emerging flux of opposite polarity. At the base of the surge we identified surge-flaring in the H filtergrams, and both blueshifts and redshifts in the H Dopplergrams. The X-ray jet appeared about 2 hours after the first appearance of the surge. The surge consisted of two ejecting threads. Initially, these two components were twisted together, then became untwisted before the appearance of the X-ray jet. This example presents an alternative scenario of plasma ejection. The magnetic reconnection in the lower atmosphere, which was responsible for the H surge, created the twisted surge threads; the X-ray jet likely resulted from a fast reconnection in the upper atmosphere, which took place well after the H surge.

Key words: Sun: chromosphere Sun: magnetic fields Sun: X-rays, gamma rays

Send offprint requests to: J. Zhang

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Contents

• 1. Introduction
• 2. Instrumentation
• 3. Observational properties
  • 3.1. Morphology and velocity
  • 3.2. Magnetic fields
  • 3.3. EUV and X-ray jet
• 4. Conclusions and discussions
• Acknowledgements
• References

© European Southern Observatory (ESO) 2000

Online publication: January 29, 2001
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