Studies of X-ray observations from PIXIE

The Polar Ionospheric X-ray Imaging Experiment (PIXIE) on board the NASA/GG S POLAR spacecraft has been making observations of ionospheric X-ray emissi ons from the vantage of space for more than 3 years. A wide variety of obse rvations have been made by PIXIE, which are detailed in this work. These in clude the local time distribution of the auroral X-ray intensity as well as the dependence of auroral X-rays on geomagnetic activity and solar wind ma gnetic field conditions. The auroral X-rays are produced as energetic elect rons within the magnetosphere precipitate and are stopped in the ionosphere . Comparisons of the X-ray auroral intensity with other instrument observat ions have been made, which enables us to distinguish between temporal and s patial processes. In addition. several other X-ray features (not of an auro ral nature) have been observed by PIXIE, and are described. (C) 2000 Elsevi er Science Ltd. All rights reserved.