MID-INFRARED SPECTROSCOPIC OBSERVATIONS OF THE DUST-FORMING CLASSICAL NOVA V2676 OPH
MID-INFRARED SPECTROSCOPIC OBSERVATIONS OF THE DUST-FORMING CLASSICAL NOVA V2676 OPH
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DOI：
10.3847/1538-3881/153/2/74
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发表时间：
2017-01
期刊：
影响因子：
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通讯作者：
H. Kawakita;T. Ootsubo;A. Arai;Y. Shinnaka;M. Nagashima
中科院分区：
文献类型：
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作者：
H. Kawakita;T. Ootsubo;A. Arai;Y. Shinnaka;M. Nagashima
形成尘埃的新星 V2676 Oph 的独特之处在于，它是第一颗在其接近最大阶段提供 C2 和 CN 分子证据以及在其早期衰退阶段提供 CO 分子证据的新星。对这颗新星的观测揭示了其光曲线的缓慢演化，并显示其包层中碳 (12C/13C) 和氮 (14N/15N) 的同位素比率较低。这些行为表明，承载 V2676 Oph 的白矮星 (WD) 是富含 CO 的 WD，而不是富含 ONe 的 WD（质量通常比前者大）。我们于 2013 年和 2014 年（分别是发现后 452 天和 782 天）对 V2676 Oph 进行了中红外光谱和光度观测。在任一时期均未检测到 12.8 μm 处的显着 [Ne ii] 发射。这些为富含 CO 的 WD 恒星托管 V2676 Oph 提供了证据。除了来自 V2676 Oph 包膜中的多环芳烃分子或氢化无定形碳颗粒的 11.4 μm 处未识别的红外特征之外，还检测到了富碳和富氧颗粒。
The dust-forming nova V2676 Oph is unique in that it was the first nova to provide evidence of C2 and CN molecules during its near-maximum phase and evidence of CO molecules during its early decline phase. Observations of this nova have revealed the slow evolution of its lightcurves and have also shown low isotopic ratios of carbon (12C/13C) and nitrogen (14N/15N) in its envelope. These behaviors indicate that the white dwarf (WD) star hosting V2676 Oph is a CO-rich WD rather than an ONe-rich WD (typically larger in mass than the former). We performed mid-infrared spectroscopic and photometric observations of V2676 Oph in 2013 and 2014 (respectively 452 and 782 days after its discovery). No significant [Ne ii] emission at 12.8 μm was detected at either epoch. These provided evidence for a CO-rich WD star hosting V2676 Oph. Both carbon-rich and oxygen-rich grains were detected in addition to an unidentified infrared feature at 11.4 μm originating from polycyclic aromatic hydrocarbon molecules or hydrogenated amorphous carbon grains in the envelope of V2676 Oph.