A study of the color diversity around maximum light in Type Ia supernovae
A study of the color diversity around maximum light in Type Ia supernovae
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DOI：
10.1051/0004-6361/201117778
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发表时间：
2011-10
影响因子：
6.5
通讯作者：
R. Cartier;F. Fórster;P. Coppi;M. Hamuy;K. Maeda;G. Pignata;Gaston Folatelli . U. de Chile;Yale;Ipmu;U. A. Bello
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文献类型：
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作者：
R. Cartier;F. Fórster;P. Coppi;M. Hamuy;K. Maeda;G. Pignata;Gaston Folatelli . U. de Chile;Yale;Ipmu;U. A. Bello
从12个观测良好的Ia型超新星的样本中，我们发现了早期阶段（U B），（V R）和（V I）颜色与从晚期阶段光谱测量的[Fe II] 7155和[Ni II] 7378星云线的速度变化之间相关的明确证据。由于这些线被认为是最初爆燃过程的灰烬，我们的研究结果为Ia型超新星偏离中心爆炸的新范式提供了额外的支持，我们将这些相关性解释为观察到的颜色中的视角效应。我们还表明，星云的速度变化的强度和宽度的Ca II H&K和IR三重线近最大光。这里提出的证据意味着，在未来基于Ia型超新星的宇宙学研究中，在推导消光值和距离时必须考虑视角。
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] �7155 and [Ni II] �7378 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.