THE ROOTS OF CORONAL STRUCTURE IN THE SUNS SURFACE

We have compared the structures seen on X-ray images obtained by a fli ght of the NIXT sounding rocket payload on July 11, 1991 with near-sim ultaneous photospheric and chromospheric structures and magnetic field s observed at Big Bear. The X-ray images reflect emission of both Mg X and Fe XVI, formed at 1 x 10(6) K and 3 x 10(6) K, respectively. The brightest H alpha sources correspond to a dying sub-flare and other ac tive region components, all of which reveal coronal enhancements situa ted spatially well above the H alpha emission. The largest set of X-ra y arches connected plages of opposite polarity in a large bipolar acti ve region. The arches appear to lie in a small range of angle in the m eridian plane connecting their footpoints. Sunspots are dark on the su rface and in the corona. For the first time we see an emerging flux re gion in X-rays and find the emission extends twice as high as the H al pha arches. Many features which we believe to correspond to 'X-ray bri ght points' (XBPs) were observed. Whether by resolution or spectral ba nd, the number detected greatly exceeds that from previous work. All o f the brighter XBPs correspond to bipolar Her features, while unipolar Ha bright points are the base of more diffuse comet-like coronal arch es, generally vertical. These diverge from individual features by less than 30 degrees, and give a good measure of what the 'canopies' must do. The H alpha data shows that all the H alpha features were present the entire day, so they are not clearly disappearing or reappearing. W e find a new class of XBPs which we call 'satellite points', elements of opposite polarity linked to nearby umbrae by invisible field lines. The satellite points change rapidly in X-ray brightness during the fl ight. An M1.9 flare occurred four hours after the flight; examination of the pre-flare structures reveals nothing unusual.