Spectroscopic observations of V455?Andromedae superoutburst in 2007: The most exotic spectral features in dwarf nova outbursts
Spectroscopic observations of V455?Andromedae superoutburst in 2007: The most exotic spectral features in dwarf nova outbursts
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2007年V455仙女座超级爆发的光谱观测：矮新星爆发中最奇特的光谱特征
DOI：
10.1093/pasj/psac007
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发表时间：
2022
影响因子：
2.3
通讯作者：
Imada Akira
中科院分区：
文献类型：
--
作者：
Tampo Yusuke;Nogami Daisaku;Kato Taichi;Ayani Kazuya;Naito Hiroyuki;Narita Norio;Fujii Mitsugu;Hashimoto Osamu;Kinugasa Kenzo;Honda Satoshi;Takahashi Hidenori;Narusawa Shin-ya;Sakamoto Makoto;Imada Akira
我们提出了我们的光谱观测V455仙女座在2007年的超级爆发。我们的观测涵盖了从爆发的光学峰到爆发后的超爆发阶段。在早期的超峰阶段，Balmer系列，Hei，Heii，Bowen混合，Civ/Nivblend的发射线被检测到。Heii 4686谱线呈现双峰发射曲线，而Balmer发射谱线是单峰，这是从其高倾斜度中出乎意料的。在普通的超级峰阶段，巴耳末系列过渡到双峰发射轮廓，高电离线显着减弱。这些过渡的线配置文件应与吸积盘的结构转变，如预期之间的早期和普通的超级驼峰过渡的热潮汐不稳定性模型。超峰早期的Hα多普勒图显示出一个以主白色矮星为中心的致密斑点。与SW Sex型激变变星类似，这种特征可能来自盘风和/或磁化白色矮星上的质量吸积柱。Heii 4686的多普勒图主要是环状结构，并有两个速度为300 km s−1的耀斑区，这对于开普勒吸积盘来说太慢了。耀斑区的相位与在早期超级峰阶段发现的内旋臂结构相一致。我们的圆盘风模型与增强发射的风分量发射从内臂结构成功地再现了所观察到的性质Heii 4686。因此，V455 And是矮新星爆发的第一个案例，其中盘风的存在是从光谱推断的。
We present our spectroscopic observations of V455 Andromedae during the 2007 superoutburst. Our observations cover this superoutburst from around the optical peak of the outburst to the post-superoutburst stage. During the early superhump phase, the emission lines of the Balmer series, Hei, Heii, Bowen blend, and Civ/Nivblend were detected. The Heii4686 line exhibited a double-peaked emission profile, where Balmer emission lines were single-peaked, which is unexpected from its high inclination. In the ordinary superhump phase, the Balmer series transitioned to double-peaked emission profiles, and high-ionization lines were significantly weakened. These transitions of the line profiles should be related to the structural transformation of the accretion disk, as expected between the early and ordinary superhump transition in the thermal–tidal instability model. The Doppler map of Hα during the early superhump phase exhibits a compact blob centered at the primary white dwarf. In analogy to SW Sex-type cataclysmic variables, this feature could emerge from the disk wind and/or the mass accretion column on to the magnetized white dwarf. The Doppler map of Heii4686 Å is dominated by the ring-like structure and imposed two flaring regions with the velocity of ∼300 km s−1, which is too slow for a Keplerian accretion disk. The phase of the flaring regions was coincident with the inner spiral arm structure identified during the early superhump phase. Our disk wind model with the enhanced emission from the wind component launched from the inner arm structure successfully reproduced the observed properties of Heii4686 Å. Therefore, V455 And is the first case in dwarf nova outbursts where the presence of the disk wind is inferred from an optical spectrum.