IR STUDY OF NOVA V2468 Cyg FROM EARLY DECLINE TO THE CORONAL PHASE
IR STUDY OF NOVA V2468 Cyg FROM EARLY DECLINE TO THE CORONAL PHASE
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NOVA V2468 Cyg 从早期衰退到冠状阶段的红外研究
DOI：
10.1088/0004-6256/149/4/136
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
M. Pak
中科院分区：
文献类型：
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作者：
A. Raj;N. Ashok;R. Rudy;R. Russell;D. Lynch;C. Woodward;M. Sitko;Amanda Day;R. B. Perry;Sang Chul Kim;M. Pak
我们目前的红外光谱和光度观测的新星V2468天鹅座涵盖期间从2008年3月13日至2008年11月11日。该天体的JHK光谱取自Mt.阿布红外天文台使用近红外成像仪/光谱仪。文中还介绍了利用NASA红外望远镜和dac仪器获得的0.8 ~ 5.2 μm的光谱。光谱主要由强H i线从Brackett和Paschen系列和Fe II，O i，和C i线在最初的日子里，典型的Fe II型新星。在爆发后的一段时间内，谱线变宽，测得的Paβ和Brγ谱线的半高宽为1800-2300 km s−1。这些数值在爆发后12天缩小到1500-1600 km s−1。爆发后36天的光谱显示出1.0830和2.0581 μm的He i谱线以及H i和O i的发射特征。我们的红外观测显示了相对较宽的发射线，光谱快速发展到更高的电离，日冕线的早期出现，以及没有尘埃发射，所有这些特征都表明了新星的混合性质。这可能是在红外波段观测到的最广泛的可能是Fe iib型新星的例子。我们还注意到Fe ii在2.0888 μm处的短寿命发射线，该发射线出现在2008年4月9日至2008年5月9日之间。从新星喷出物中没有看到尘埃排放。我们还估计V2468 Cyg的喷出物质量范围为3 × 10−6-10− 5 M？.
We present infrared spectroscopic and photometric observations of the nova V2468 Cyg covering the period from 2008 March 13 to 2008 November 11. The JHK spectra of the object were taken from the Mt. Abu Infrared Observatory using the Near-Infrared Imager/Spectrometer. Spectra from 0.8 to 5.2 μm that were obtained using the NASA Infrared Telescope Facility and the SPEX instrument are also presented. The spectra are dominated by strong H i lines from the Brackett and Paschen series and Fe ii, O i, and C i lines in the initial days, typical of an Fe ii type nova. The lines were broader in the period immediately after outburst, with measured FWHMs of 1800–2300 km s−1 for the Paβ and Brγ lines. These values narrowed to 1500–1600 km s−1 by 12 days from the outburst. The spectra showed prominent He i lines at 1.0830 and 2.0581 μm together with H i and O i emission features after 36 days from the outburst. Our IR observations show the comparatively broad emission lines, the rapid development of the spectrum to higher ionization, the early appearance of coronal lines, and the absence of dust emission, all features that indicate the hybrid nature of the nova. This is perhaps the most extensively observed example of a probable Fe iib type nova at infrared wavelengths. We also note a short lived emission line of Fe ii at 2.0888 μm, which was present between 2008 April 9 and 2008 May 9. No dust emission is seen from the nova ejecta. We have also estimated the range for the ejecta mass in V2468 Cyg to be 3 × 10−6–10−5M ⊙ ?> .