An Hβ surge and X-ray jet – Magnetic properties and velocity patterns

We described simultaneous observations of a surge in Hβ and an X-ray jet in NOAA 8100 on November 1, 1997. We found that the Hβ 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 Hβ filtergrams, and both blueshifts and redshifts in the Hβ 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 Xray jet. This example presents an alternative scenario of plasma ejection. The magnetic reconnection in the lower atmosphere, which was responsible for the Hβ 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 Hβ surge.