Artículos de revistas
A study of the color diversity around maximum light in Type Ia supernovae
Fecha
2011Registro en:
A&A 534, L15 (2011)
DOI: 10.1051/0004-6361/201117778
Autor
Cartier Ugarte, Regis
Förster, F.
Coppi, C.
Hamuy Wackenhut, Mario
Maeda, K.
Pignata Libralato, Giuliano
Folatelli, Gastón
Institución
Resumen
From a sample of 12 well-observed Type Ia supernovae, we find clear evidence of correlations between early phase (U − B), (V − R),
and (V − I) colors and the velocity shifts of the [Fe II] λ7155 and [Ni II] λ7378 nebular lines measured from late-phase spectra. As
these lines are thought to trace the ashes of the initial deflagration process, our findings provide additional support to the new paradigm
of off-center explosions in Type Ia supernovae, and we interpret these correlations as viewing angle effects in the observed colors. We
also show that the nebular velocity shifts are related to the strength and width of the Ca II H&K and IR-triplet lines near-maximum
light. The evidence presented here implies that the viewing angle must be taken into account when deriving extinction values and
distances in future cosmological studies based on Type Ia supernovae.