OPTICAL-IMAGES AND SPECTRA OF THE GALACTIC SUPERNOVA REMNANT G109.1-1.0

H alpha and [O III] images of the galactic SNR G109.1-1.0 plus optical spectra of five associated emission filaments and two neighboring H II regions are presented. These data show the remnant's optical filaments are more extensive and have a larger diffuse component than previously realized. New filamentary emission is also detected near G109.1-1.0's projected center, along the SW edge of the remnant's bright x-ray blob. Balmer decrements for five filaments indicate significant variations in optical reddening, E(B - V) = 0.79-1.2 mag, on both large and small spatial scales. [S II] lambda 6716/lambda 6731 line ratios indicate filament electron densities of less than or equal to 100-800 cm(-3), with the high end of this range implying preshock densities similar or equal to 20 cm(-3). These relatively high densities, together with the tendency of the remnant's optical emission to lie along the boundaries of faint H II regions to the north and southeast, suggest that much of G109.1-1.0's optical emission may be the result of its interaction with these H II regions. (C) 1995 American Astronomical Society.