The Astrophysical Journal
We present near-infrared spectra of late-phase (>200 days) Type Ia supernovae (SNe Ia) taken at the Subaru Telescope. The [Fe II] line of SN 2003hv shows a clear flat-topped feature, while that of SN 2005W shows a less prominent flatness. In addition, a large shift in their line center, varying from -3000 to 1000 km s-1 with respect to the host galaxies, is seen. Such a shift suggests the occurrence of an off-center, nonspherical explosion in the central region and provides important, new constraints on the explosion models of SNe Ia.
Motohara, Kentaro; Maeda, Keiichi; Gerardy, Christopher L.; Nomoto, Ken'ichi; Tanaka, Masaomi; Tominaga, Nozomu; Ohkubo, Takuya; Mazzali, Paolo A.; Fesen, Robert A.; Hoflich, Peter; and Wheeler, J. Craig, "The Asymmetric Explosion of Type Ia Supernovae as Seen from Near-Infrared Observations" (2006). Open Dartmouth: Faculty Open Access Articles. 3389.