The properties of the 'standard' Type Ic supernova 1994I from spectral models

The properties of the Type Ic supernova SN 1994I are reinvestigated. This object is often referred to as a 'standard SN Ic' although it exhibited an extremely fast light curve and unusually blue early-time spectra. In addition, the observations were affected by significant dust extinction. A series of spectral models is computed based on the explosion model CO21 using a Monte Carlo transport spectral synthesis code. Overall the density structure and abundances of the explosion model are able to reproduce the photospheric spectra well. Reddening is estimated to be E(B - V) = 0.30 mag, a lower value than previously proposed. A model of the nebular spectrum of SN 1994I points towards a slightly larger ejecta mass than that of CO21. The photospheric spectra show a large abundance of iron-group elements at early epochs, indicating that mixing within the ejecta must have been significant. We present an improved light curve model which also requires the presence of Ni-56 in the outer layers of the ejecta.