Here we present previously unpublished optical spectra of supernova (SN) 2001ig, a Type IIb SN, from about a week after explosion until nearly one year later. The earliest spectrum consists of only a few broad absorption features, but soon more common Type II SN features including hydrogen P Cygni profiles and helium absorption become apparent. At later times, as the H features fade and the He I absorption becomes more prominent, we observe the SN to transition from a Type II to a Type Ib. Finally, observations after 250 days past explosion show a nebular-phase SN spectrum with one of the largest magnesium to oxygen intensity ratios ever seen. Additionally, we present models of the late-time spectra which indicate that the inner ejecta consist of ∼1:15 M⊙ of material, most of which (by mass) is in the form of oxygen, with ∼0:13 M⊙ of 56Ni and essentially no hydrogen.
|Original language||English (US)|
|Number of pages||10|
|Journal||Publications of the Astronomical Society of the Pacific|
|State||Published - Jul 2009|
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science