Direct Analysis of Spectra of Type Ic Supernovae

Synthetic spectra generated with the parameterized supernova synthetic-spectrum code SYNOW are compared with observed photospheric-phase optical spectra of the normal Type Ic SN 1994I and the peculiar Type Ic SNe 1997ef and 1998bw. The observed spectra can be matched fairly well with synthetic spectra that are based on spherical symmetry and that include lines of just a few ions that are expected to appear on the basis of LTE calculations. Spectroscopic estimates of the mass and kinetic energy of the line-forming layers of the ejected matter give conventional values for SN 1994I but high kinetic energy ($\sim 30 \times 10^{51}$ erg) for SN 1997ef and even higher ($\sim 60 \times 10^{51}$ erg) for SN 1998bw. It is likely that even if SNe 1997ef and 1998bw were non-spherical, they also were hyper-energetic.