The Peculiar SN 2005hk: Do Some Type Ia Supernovae Explode as Deflagrations?
The Peculiar SN 2005hk: Do Some Type Ia Supernovae Explode as Deflagrations?
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DOI：
10.1086/518372
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发表时间：
2006-11
影响因子：
3.5
通讯作者：
M. Phillips;Weidong Li;J. Frieman;J. Frieman;Sergei Blinnikov;D. Depoy;J. Prieto;Peter Milne-
中科院分区：
文献类型：
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作者：
M. Phillips;Weidong Li;J. Frieman;J. Frieman;Sergei Blinnikov;D. Depoy;J. Prieto;Peter Milne-
我们给出了Ia型超新星(SN)2005hk的广泛的u‘gr’i‘BVRIYJHKs光度和光谱。这些数据表明，SN2005hk的观测性质与SN2002cx几乎完全相同，后者被称为“最奇特的Ia型超新星”。这两颗超新星都表现出高电离的SN1991T类极大值前光谱，但峰值亮度却像SN1991bg的那样低。光谱显示，与SN2002cx一样，SN2005hk的膨胀速度大约是典型的Ia型超新星的一半。这两颗超新星的R和I光曲线也很特殊，没有显示正常Ia型超新星观测到的第二大值。我们对SN2005HK的YJH测光在近红外波段也显示出同样的特性。通过将我们对SN 2005hk的光学和近红外光度测量与SWIFT卫星获得的已公布的紫外光曲线相结合，我们能够构建从∼前15天到B最大值后60天的∼测辐射热光曲线。这条光曲线的形状和异常低的峰值光度，加上在红光和近红外波段的低膨胀速度和没有第二极大值，都与产生56Ni的∼0.2M⊙的三维爆燃模型计算合理一致。
We present extensive u′g′r′i′BVRIYJHKs photometry and optical spectroscopy of the Type Ia supernova (SN) 2005hk. These data reveal that SN 2005hk was nearly identical in its observed properties to SN 2002cx, which has been called “the most peculiar known Type Ia supernova.” Both supernovae exhibited high‐ionization SN 1991T–like premaximum spectra, yet low peak luminosities like that of SN 1991bg. The spectra reveal that SN 2005hk, like SN 2002cx, exhibited expansion velocities that were roughly half those of typical Type Ia supernovae. The R and I light curves of both supernovae were also peculiar in not displaying the secondary maximum observed for normal Type Ia supernovae. Our YJH photometry of SN 2005hk reveals the same peculiarity in the near‐infrared. By combining our optical and near‐infrared photometry of SN 2005hk with published ultraviolet light curves obtained with the Swift satellite, we are able to construct a bolometric light curve from ∼15 days before to ∼60 days after B maximum. The shape and unusually low peak luminosity of this light curve, plus the low expansion velocities and absence of a secondary maximum at red and near‐infrared wavelengths, are all in reasonable agreement with model calculations of a three‐dimensional deflagration that produces ∼0.2 M⊙ of 56Ni.