CORE STRUCTURE OF M32 FROM SEEING-DECONVOLVED IMAGES

We present results of two-color (Gunn-Thuan gr) CCD surface photometry and seeing deconvolution of the central region of M32 (NGC 221), using the regularized multi-Gaussian (RMG) method, a powerful nonlinear technique. The galaxy core remains essentially unresolved at the limit of our data, i.e., the core radius is r(c) less-than-or-equal-to 0.42 arcsec congruent-to 1.4 pc. We also present a deprojected luminosity density profile of the galaxy, from a multi-Gaussian fit to a combined profile from our own data, and the profile measured at large radii by Kent [AJ, 94, 306(1987)]. We obtain for the central luminosity density approximately 1.74 x 10(5) L.v/pc3, which should be regarded as a lower limit. Using the published measurements of the velocity dispersion, in the King-Minkowski approximation we obtain for the central (M/L(v)) congruent-to 3, which is also probably a lower limit. Assuming this value of (M/L(v)), we derive the central relaxation time t(rc) congruent-to 2 x 10(9) yr, which should also probably be regarded as an upper limit. The surface brightness profile near the center is represented very well with a power-law cusp of the slope of - 1.2, which is characteristic of some theoretical models of post-core collapse stellar systems. It is thus plausible that normal dynamical evolution over the Hubble time, possibly accelerated by the tidal interaction with M31, has lead to the core collapse in M32, and even to the formation of a central black hole. A color gradient appears at radii less-than-or-equal-to 1 arcsec, with the center being redder, and with a roughly constant (g - r) color outside that radius; a similar effect has been seen independently by Michard & Nieto [A&AL, 243, L17 (1991)]. This may be caused by a compact dust feature near the center.