论文标题
WISEA J041451.67-585456.7和WISEA J181006.18-101000.5：第一个极端T型Subdwarfs？
WISEA J041451.67-585456.7 and WISEA J181006.18-101000.5: The First Extreme T-type Subdwarfs?
论文作者
论文摘要
我们介绍了WISEA J041451.67-585456.7和WISEA J181006.18-101000.5的发现，两个低温（1200 $ - $ 1400 K），高适当的运动T型Pepe subdwarfs。这两个对象都是通过其高正确的运动（$> $> 0.5 arcsec yr $^{ - 1} $）发现的； WISEA J181006.18-101000.5作为Neowise适当运动调查的一部分，WISEA J041451.67-585456.7作为公民科学项目后院世界的一部分；行星9。我们已经确认这两个矮人都有近红外光谱的后续矮人。它们的光谱和近红外颜色在已知的棕色矮人中是独一无二的，其中有些颜色与L型棕色矮人和其他类似于最新型T矮人的颜色一致。虽然没有前向模型始终重现其近红外光谱中看到的特征，但最接近的匹配表明金属性非常低（[fe/h] $ \ leq $ -1），使这些对象可能是T光谱类别（ESDT）极端分类的第一个示例。 WISEA J041451.67-585456.7和WISEA J181006.18-101000.5被发现是占据“替代过渡区”的少数物体的一部分，并且在该组中所有对象的质量最低和有效的温度。
We present the discoveries of WISEA J041451.67-585456.7 and WISEA J181006.18-101000.5, two low-temperature (1200$-$1400 K), high proper motion T-type subdwarfs. Both objects were discovered via their high proper motion ($>$0.5 arcsec yr$^{-1}$); WISEA J181006.18-101000.5 as part of the NEOWISE proper motion survey and WISEA J041451.67-585456.7 as part of the citizen science project Backyard Worlds; Planet 9. We have confirmed both as brown dwarfs with follow-up near-infrared spectroscopy. Their spectra and near-infrared colors are unique amongst known brown dwarfs, with some colors consistent with L-type brown dwarfs and other colors resembling those of the latest-type T dwarfs. While no forward model consistently reproduces the features seen in their near-infrared spectra, the closest matches suggest very low metallicities ([Fe/H] $\leq$ -1), making these objects likely the first examples of extreme subdwarfs of the T spectral class (esdT). WISEA J041451.67-585456.7 and WISEA J181006.18-101000.5 are found to be part of a small population of objects that occupy the "substellar transition zone," and have the lowest masses and effective temperatures of all objects in this group.
