The Schizophrenic Spectrum of LSR 1610−0040: A Peculiar M Dwarf/Subdwarf
The Schizophrenic Spectrum of LSR 1610−0040: A Peculiar M Dwarf/Subdwarf
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LSR 1610−0040 的精神分裂谱：特殊的 M 矮人/亚矮人
DOI：
10.1086/499583
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
W. Vacca
中科院分区：
文献类型：
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作者：
M. Cushing;W. Vacca
我们给出了一颗高自行恒星LSR1610-0040的中分辨率(R≡λ/Δλ≈2 0 0 0)，0.8-4.1μm光谱，这颗恒星是L等人根据其红光光谱分类为早期L亚矮星的。LSR1610-0040的近红外光谱不符合(初步)M/L亚矮星序列，而是混合了M矮星和M亚矮星的光谱特征。特别是近红外光谱在K波段和Al-I、K-I谱线上出现了安娜I双态和CO泛音谱头，在H波段出现了FeH谱头，所有这些谱线都具有更典型的M矮星强度。此外，GL406(M6V)的光谱与LSR1610-0040的0.64.1μm光谱能量分布有相当好的匹配。然而，LSR1610-0040的近红外光谱也显示出与M亚矮星相同的光谱特征，包括以∼0.97μm为中心的强Tii多重态，在∼1.06μm处的弱VO带，以及在H和K带可能由碰撞诱导的H2吸收。我们讨论了LSR1610-0040红光和近红外光谱出现的一些可能的解释。虽然我们无法对LSR1610-0040进行明确的分类，但大多数证据表明它是一颗轻度缺乏金属的M矮星。最后，我们在M矮星的光谱中初步确定了∼为0.93μm处的一个新的二氧化钛谱带。
We present a moderate-resolution (R ≡ λ/Δλ ≈ 2000), 0.8-4.1 μm spectrum of LSR 1610-0040, a high proper motion star classified as an early-type L subdwarf by Lépine and collaborators based on its red-optical spectrum. The near-infrared spectrum of LSR 1610-0040 does not fit into the (tentative) M/L subdwarf sequence but rather exhibits a mix of characteristics found in the spectra of both M dwarfs and M subdwarfs. In particular, the near-infrared spectrum exhibits an Na I doublet and CO overtone band heads in the K band and Al I and K I lines and an FeH band head in the H band, all of which have strengths more typical of field M dwarfs. Furthermore, the spectrum of Gl 406 (M6 V) provides a reasonably good match to the 0.6-4.1 μm spectral energy distribution of LSR 1610-0040. Nevertheless, the near-infrared spectrum of LSR 1610-0040 also exhibits features common to the spectra of M subdwarfs, including a strong Ti I multiplet centered at ∼0.97 μm, a weak VO band at ∼1.06 μm, and possible collision-induced H2 absorption in the H and K bands. We discuss a number of possible explanations for the appearance of the red-optical and near-infrared spectra of LSR 1610-0040. Although we are unable to definitively classify LSR 1610-0040, the preponderance of evidence suggests that it is a mildly metal-poor M dwarf. Finally, we tentatively identify a new band of TiO at ∼0.93 μm in the spectra of M dwarfs.