SPECTROSCOPY OF THE SUPERNOVA REMNANT CTB-1

We have obtained spectra at 11 positions within the supernova remnant CTB 1 using the Automated Multi-Object Spectrometer (AMOS) at Lick Observatory. We determined the bulk velocity of the remnant and performed a global study of important emission lines from the shock-heated ISM. As these are the first results reported from this instrument, we chose some positions to overlap those of earlier observers. We measured a mean velocity for the remant of -35 +/- 6 km s-1 placing CTB 1 at a kinematic distance of 3.1 +/- 0.4 kpc. This distance corresponds to that of an OB association in the Perseus arm. We also establish a probable age for the remnant of approximately 7500-11,000 years. The spatially resolved spectroscopy reveals a significant gradient in the strength of the [N II] forbidden lines as a function of azimuthal distance along the rim of the remnant. The most likely explanation for this gradient is a smooth variation in the density in the ambient ISM, which would produce a similar variation in the radiative shock velocity. The wide range in line ratio values across the remnant indicate that caution must be exercised when evaluating global properties of supernova remnants based on spectra from only a few filaments in individual remnants.