The Ionization Mechanism of LINER Galaxy NGC1052

We present a study of archival Hubble Space Telescope (HST) data of the low ionization nuclear emission line region (LINER) galaxy, NGC1052. The WFPC2 imagery clearly differentiates extended nebular emission from the compact core. Faint Object Spectrograph (FOS) observations provide a full set of optical UV data (1200-6800 Angstroms). This data set samples the innermost region (0."86 x 0."86 ~ 82pc x 82pc) and excludes the extended emission, which may be powered by different processes than the compact component. Furthermore, the extensive set of available emission line data allows a detailed analysis of the physical conditions within the nucleus. From the measured Hα /Hβ ratio, we find significant internal reddening (E(B-V)=0.42) for the nuclear emission. Photoionization models using a two component power law spectra are computed, using the fewest assumptions possible. The dereddened emission line fluxes can be well fit by a simple model comprised of a gas that is stratified in density and photoionized by a rather flat central continuum source, alpha_ {uv}=-1.2 and alpha_ {x}=-0.7. We compare these results to previous studies that included modeling by shocks.