Late-time emission of type Ia supernovae: optical and near-infrared observations of SN 2001el
Late-time emission of type Ia supernovae: optical and near-infrared observations of SN 2001el
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DOI：
10.1051/0004-6361:20066999
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发表时间：
2007-05
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影响因子：
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通讯作者：
M. Stritzinger;Jesper Sollerman Dark Cosmoglogy Centre;Niels Bohr Institutet;Kobenhavns Universitet Stockholm Observatory
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文献类型：
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作者：
M. Stritzinger;Jesper Sollerman Dark Cosmoglogy Centre;Niels Bohr Institutet;Kobenhavns Universitet Stockholm Observatory
我们给出了用甚大望远镜获得的SN 2001el在最大光后310至445天的光学和近红外光曲线。晚时光学（UBVRI）光曲线在U、B、V、R和I波段的衰减时间尺度分别为1.43\pm0.14、1.43\pm0.06、1.48\pm0.06、1.45\pm0.07和1.03\pm0.07等（每百天），呈近似线性衰减。相比之下，在近红外波段（jhk），通量的时间演化在这些时期似乎几乎是恒定的。我们在J和H波段分别测量了0.19\pm0.10和0.17\pm0.11等的下降率（每百天）。我们构造了UVOIR光曲线，发现晚时光度的衰减时间尺度与正电子动能的完全沉积几乎一致。正常Ia型SN 2001el的后期光曲线表明近红外贡献的重要性增加。这是以前在特殊的SN 2000cx中观察到的，因此SN 2001el的结果确保了以前基于单个特殊事件的结论适用于正常的Ia型超新星。测量的后期UVOIR衰减率表明，大部分正电子被困在喷射物中。这一结果不利于弱和/或径向梳状磁场结构的预测。
We present optical and near-infrared light curves of SN 2001el from 310 to 445 days past maximum light, obtained with the Very Large Telescope. The late-time optical (UBVRI) light curves decay in a nearly linear fashion with decay time scales of 1.43\pm0.14, 1.43\pm0.06, 1.48\pm0.06, 1.45\pm0.07, and 1.03\pm0.07 magnitudes (per hundred days) in the U, B, V, R and I bands, respectively. In contrast, in the near-infrared (JHKs) bands the time evolution of the flux appears to be nearly constant at these epochs. We measure decline rates (per hundred days) of 0.19\pm0.10 and 0.17\pm0.11 magnitudes in the J and H bands, respectively. We construct a UVOIR light curve, and find that the late-time luminosity has a decay time scale nearly consistent with complete depostion of positron kinetic energy. The late-time light curves of the normal type Ia SN 2001el demonstrate the increased importance of the near-infrared contribution. This was previously observed in the peculiar SN 2000cx, and the results for SN 2001el thus ensure that the conclusions previously based on a single peculiar event are applicable to normal type Ia supernovae. The measured late-time UVOIR decline rate suggests that a majority of the positrons are trapped within the ejecta. This results does not favor the predictions of a weak and/or radially combed magnetic field configuration.