IMPROVED EVIDENCE FOR A BLACK-HOLE IN M32 FROM HST FOS SPECTRA .1. OBSERVATIONS/

We have obtained spectra through small apertures centered on the nucle ar region and major axis of M32 with the Faint Object Spectrograph (FO S) on the Hubble Space Telescope (HST). A detailed analysis and reduct ion of the data is presented, including (1) new calibrations and model ing of the FOS aperture sizes, point-spread function, and line-spread functions; (2) determination of the aperture positioning for each obse rvation from the observed count rate; and (3) accurate wavelength cali bration, template matching, and kinematical analysis of the spectra. T his yields measurements of the stellar rotation velocities and velocit y dispersions near the center of M32 with spatial resolution that is 5 times higher than the best available ground-based data. The inferred velocities provide the highest angular-resolution stellar-kinematical data obtained to date for any stellar system. The HST observations sho w a steeper rotation curve and higher central velocity dispersion than the ground-based data. The rotation velocity is observed to be simila r to 30 km s(-1) at 0.'' 1 from the nucleus. This is roughly twice the value measured from the ground at this distance. The nuclear dispersi on measured through the smallest FOS aperture (0.'' 068 square) is 156 +/- 10 km s(-1). The average of four independent dispersion measureme nts at various positions inside the central 0.'' 1 is 126 km s(-1), wi th a rms scatter of 21 km s(-1). The nuclear dispersion measured from the ground is only 85-95 km s(-1), whereas the dispersion outside the central arcsecond is only similar to 45-55 km s(-1). These results sig nificantly strengthen previous arguments for the presence of a massive nuclear black hole in M32. Detailed dynamical models are presented in a series of companion papers.