Seventy-One New L and T Dwarfs from the Sloan Digital Sky Survey
Seventy-One New L and T Dwarfs from the Sloan Digital Sky Survey
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DOI：
10.1086/501431
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发表时间：
2006-01
期刊：
影响因子：
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通讯作者：
K. Chiu;X. Fan;S. Leggett;D. Golimowski;W. Zheng;T. Geballe;D. Schneider;J. Brinkmann
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文献类型：
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作者：
K. Chiu;X. Fan;S. Leggett;D. Golimowski;W. Zheng;T. Geballe;D. Schneider;J. Brinkmann
我们展示了对 71 个新发现的 L 型和 T 型矮星的近红外观测结果，这些矮星是使用 i-dropout 技术从斯隆数字巡天 (SDSS) 的成像数据中选出的。其中 65 颗矮星已根据 Geballe 等人的近红外 L 矮星分类方案进行了光谱分类。以及 Burgasser 等人的统一 T 矮星分类方案。这些矮星的光谱类型范围从 L3 到 T7，包括 SDSS 中发现的最新类型。新发现的矮星中有六颗根据其光度近红外颜色被分类为早到中L矮星，另外两颗在光度上被分类为M矮星。我们还提供了五颗先前发表的 SDSS L 和 T 矮星以及 Burgasser 等人发现的一颗 L 矮星和一颗 T 矮星的新近红外光谱。来自两微米全天巡天。新的 SDSS 样本包括 27 个 T 矮星和 30 个光谱类型跨越复杂 L-T 跃迁 (L7-T3) 的矮星。我们继续看到 L3-T1 类型的 J - H 存在较大的（∼0.5 mag）分布，并且 L3 之后的所有矮星的 H - K 都有类似的分布。这种颜色分散可能是由于一系列颗粒沉降特性、金属丰度和重力造成的。我们还发现 L 矮星和 T 矮星具有不寻常的颜色和光谱特性，最终可能有助于解开这些效应。
We present near-infrared observations of 71 newly discovered L and T dwarfs, selected from imaging data of the Sloan Digital Sky Survey (SDSS) using the i-dropout technique. Sixty-five of these dwarfs have been classified spectroscopically according to the near-infrared L dwarf classification scheme of Geballe et al. and the unified T dwarf classification scheme of Burgasser et al. The spectral types of these dwarfs range from L3 to T7 and include the latest types yet found in the SDSS. Six of the newly identified dwarfs are classified as early to mid-L dwarfs according to their photometric near-infrared colors, and two others are classified photometrically as M dwarfs. We also present new near-infrared spectra for five previously published SDSS L and T dwarfs, and one L dwarf and one T dwarf discovered by Burgasser et al. from the Two Micron All Sky Survey. The new SDSS sample includes 27 T dwarfs and 30 dwarfs with spectral types spanning the complex L-T transition (L7-T3). We continue to see a large (∼0.5 mag) spread in J - H for L3-T1 types and a similar spread in H - K for all dwarfs later than L3. This color dispersion is probably due to a range of grain sedimentation properties, metallicity, and gravity. We also find L and T dwarfs with unusual colors and spectral properties that may eventually help to disentangle these effects.