The nuclear dynamics of M32. I. Data and stellar kinematics

We have obtained optical long-slit spectroscopy of the nucleus of M32 using the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope . The stellar rotation velocity and velocity dispersion, as well as the ful l line-of-sight velocity distribution (LOSVD), were determined as a functio n of position along the slit using two independent spectral deconvolution a lgorithms. We see three clear kinematical signatures of the nuclear black h ole : a sudden upturn, at similar to0."3 from the center, in the stellar ve locity dispersions; a flat or rising rotation curve into the center; and st rong, non-Gaussian wings on the central LOSVD. The central velocity dispers ion is similar to 130 km s(-1) (Gaussian fit) or greater than or similar to 175 km s(-1) (corrected for the wings). The central kinematics are consist ent with the presence of a supermassive compact object in M32 with a mass i n the range (2-4) x 10(6) M..