Polar cap X-rays and electrons under low density solar wind conditions: Coordinated PIXIE and DMSP observations on 11 May 1999

X-ray images from 11 May 1999 typically show emissions filling a region abo ve about 75 degrees - 80 degrees magnetic latitude with the emitting region centered a few degrees toward mid-morning from the magnetic pole during a period when the solar wind reached unusually low values. Ionospheric partic le measurements show the entire northern polar cap illuminated by precipita ting electrons during much of this time, while the southern polar cap was m ostly "dark." The precipitating electrons had multicomponent spectra, one c omponent with characteristic energy similar to 200 eV throughout the observ ation period, and others with time-varying characteristic energies ranging between similar to3.5 keV and 10 keV, all components with spatial character istics common to polar rain. Measurements in the solar wind also show simil ar multicomponent spectra and are relatively well correlated with observati ons of solar radio bursts and the polar-cap x-ray flux. We conclude that th e higher energy components were associated with electrons accelerated in so lar flares or coronal flare-like events.