SN 2009ip at late times - an interacting transient at +2 years
SN 2009ip at late times - an interacting transient at +2 years
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DOI：
10.1093/mnras/stv1919
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发表时间：
2015-02
影响因子：
4.8
通讯作者：
M. Fraser;R. Kotak;A. Pastorello;A. Jerkstrand;S. Smartt;Ting-Wan Chen;M. Childress;G. Gilmore
中科院分区：
文献类型：
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作者：
M. Fraser;R. Kotak;A. Pastorello;A. Jerkstrand;S. Smartt;Ting-Wan Chen;M. Childress;G. Gilmore
我们提出了在2013年和2014年观测季节期间拍摄的相互作用瞬态SN 2009 ip的光度和光谱观测。我们将光度演化描述为所有波段的稳定而平滑的下降，其下降速率比仅为$^{56}$Co动力超新星在后期阶段的预期要慢。从2012年12月到2014年12月的两年时间里没有看到进一步的爆发或喷发。SN 2009 ip仍然比发现前的图像中的历史最小值更亮。从光谱上看，SN 2009 ip仍然以H、He、Ca和Fe的强窄（2000 km~s ^{-1}$）发射线为主。虽然我们分别在2013年6月底和2013年10月初探测到[Fe~{\sc ii}] 7155和[O~{\sc i}] 6300，6364线，但我们没有看到可以指向核心坍缩起源的强宽星云发射线。一般来说，这些谱线看起来相对对称，除了我们在2014年5月的最后一个谱线，当时我们观察到在+550 km~s$^{-1}$处出现了红移的发射肩。谱线没有蓝移，我们没有看到明显的近红外或中红外过量。从SN 2009 ip的光谱和光度演化到2012 a事件开始后的820天，我们仍然没有看到核心坍缩的决定性证据，尽管任何这样的迹象是否会被持续的相互作用所掩盖还不清楚。
We present photometric and spectroscopic observations of the interacting transient SN 2009ip taken during the 2013 and 2014 observing seasons. We characterise the photometric evolution as a steady and smooth decline in all bands, with a decline rate that is slower than expected for a solely $^{56}$Co-powered supernova at late phases. No further outbursts or eruptions were seen over a two year period from 2012 December until 2014 December. SN 2009ip remains brighter than its historic minimum from pre-discovery images. Spectroscopically, SN 2009ip continues to be dominated by strong, narrow ($\lesssim$2000 km~s$^{-1}$) emission lines of H, He, Ca, and Fe. While we make tenuous detections of [Fe~{\sc ii}] $\lambda$7155 and [O~{\sc i}] $\lambda\lambda$6300,6364 lines at the end of 2013 June and the start of 2013 October respectively, we see no strong broad nebular emission lines that could point to a core-collapse origin. In general, the lines appear relatively symmetric, with the exception of our final spectrum in 2014 May, when we observe the appearance of a redshifted shoulder of emission at +550 km~s$^{-1}$. The lines are not blue-shifted, and we see no significant near- or mid-infrared excess. From the spectroscopic and photometric evolution of SN 2009ip until 820 days after the start of the 2012a event, we still see no conclusive evidence for core-collapse, although whether any such signs could be masked by ongoing interaction is unclear.