Direct Spectral Analysis of the Type Ic Supernova 1994I

Session 39 - Supernovae.
Display session, Thursday, January 08
Exhibit Hall,

[39.04] Direct Spectral Analysis of the Type Ic Supernova 1994I

J. Deaton, D. Branch (U. Oklahoma), A. Fisher (Southwestern Oklahoma State University), E. Baron (U. Oklahoma)

We use a parameterized spectrum-synthesis code to analyze spectra of the type Ic SN 1994I. We discuss the identification of the absorption feature observed near 10250Åwhich has been identified with \lambda10830 of He I and widely accepted as convincing evidence that SNe Ic eject helium. Our analysis does not rule out the presence of helium, but we find it difficult to attribute the core of this feature to He I \lambda10830 without compromising our fit to the optical spectrum. We discuss other candidates, including C I \lambda10691, Mg II \lambda10930, and a blend of infrared Si I lines. Of these, we find that only Si I provides a good fit to the entire observed absorption feature while maintaining the fit in the optical. Our findings, based on a comparatively simple, parameterized spectrum synthesis procedure, must be checked by means of detailed non--LTE calculations.

Program listing for Thursday