ORFEUS IT Echelle spectra: molecular hydrogen at high velocities toward HD93521

Absorption lines of interstellar molecular hydrogen in the far ultraviolet (FUV) have been observed in the spectrum of the O9.5 halo star HD 93521, lo cated some 1500 pc from the Galactic plane. During the second ORFEUS-SPAS m ission a spectrum with the Echelle spectrometer has been recorded with a to tal integration time of 1740 a. The resolution achieved was about lambda/De lta lambda greater than or equal to 10.000 with a signal-to-noise ratio of up to 25. For the first time two components of molecular hydrogen have been observed in absorption at velocities of similar or equal to -12 km s(-1) i n the Galactic disk and at similar or equal to -62km s(-1) located presumab ly in the Galactic halo. The column densities derived from a standard curve of growth analysis were found to be N(H-2) = 10(17.0) cm(-2) for the disk component and N(H-2)=10(14.6) cm(-2) respectively for the component located in the Galactic halo.