SPECTROSCOPY OF TYPE Ia SUPERNOVAE BY THE CARNEGIE SUPERNOVA PROJECT
SPECTROSCOPY OF TYPE Ia SUPERNOVAE BY THE CARNEGIE SUPERNOVA PROJECT
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DOI：
10.1088/0004-637x/773/1/53
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发表时间：
2013-05
期刊：
影响因子：
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通讯作者：
G. Folatelli;N. Morrell;M. Phillips;E. Hsiao;A. Campillay;C. Contreras;S. Castellón;M. Hamuy-
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文献类型：
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作者：
G. Folatelli;N. Morrell;M. Phillips;E. Hsiao;A. Campillay;C. Contreras;S. Castellón;M. Hamuy-
这是卡内基超新星计划首次公布的低红移Ia型超新星（SNe Ia）的光谱数据，包括604个以前未公布的93个SNe Ia的光谱。观测涵盖了从B波段最大光出现前12天到B波段最大光出现后150多天的一系列阶段。通过对文献中228个近最大值光谱的分析，我们定量地研究了Ia超新星的多样性。为此，采用光谱参数，例如来自光谱线蓝移的膨胀速度和伪等效宽度（pW）。这些参数的值在最大光78个对象，从而提供了一个表征的超新星Ia，可能有助于提高我们的理解的爆炸系统和热核火焰传播的属性。两个天体，即SNe 2005 M和2006 is，从样本中脱颖而出，显示出特殊的Si ii和S ii速度，但其余离子的速度则是标准速度。我们进一步研究了光谱和光度参数之间的相关性，如光变曲线下降率和颜色。与以前的研究一致，我们发现Si II吸收特性的pW是光变曲线下降率的非常好的指标。此外，我们证明，参数，如pW 2（Si ii 4130）和pW 6（Si ii 5972）提供了色散为10.15 mag.的B带峰值亮度的精确校准。在寻找Ia超新星峰值亮度校准中的第二个参数时，我们发现B波段哈勃残差与Sii和Sii线的最大光速之间存在σ 2σ-3σ相关。
This is the first release of optical spectroscopic data of low-redshift Type Ia supernovae (SNe Ia) by the Carnegie Supernova Project including 604 previously unpublished spectra of 93 SNe Ia. The observations cover a range of phases from 12 days before to over 150 days after the time of B-band maximum light. With the addition of 228 near-maximum spectra from the literature, we study the diversity among SNe Ia in a quantitative manner. For that purpose, spectroscopic parameters are employed such as expansion velocities from spectral line blueshifts and pseudo-equivalent widths (pW). The values of those parameters at maximum light are obtained for 78 objects, thus providing a characterization of SNe Ia that may help to improve our understanding of the properties of the exploding systems and the thermonuclear flame propagation. Two objects, namely, SNe 2005M and 2006is, stand out from the sample by showing peculiar Si ii and S ii velocities but otherwise standard velocities for the rest of the ions. We further study the correlations between spectroscopic and photometric parameters such as light-curve decline rate and color. In agreement with previous studies, we find that the pW of Si ii absorption features are very good indicators of light-curve decline rate. Furthermore, we demonstrate that parameters such as pW2 (Si ii 4130) and pW6 (Si ii 5972) provide precise calibrations of the peak B-band luminosity with dispersions of ≈0.15 mag. In the search for a secondary parameter in the calibration of peak luminosity for SNe Ia, we find a ≈2σ–3σ correlation between B-band Hubble residuals and the velocity at maximum light of S ii and Si ii lines.