论文标题
奇特矮人明智的J181005.5 $ - $ 101002.3的物理特性和三角距离
Physical properties and trigonometric distance of the peculiar dwarf WISE J181005.5$-$101002.3
论文作者
论文摘要
我们的目标是表征金属贫困棕色矮人种群的物理特性。特别是，我们专注于最近发现的奇特矮人明智的J1810055 $ - $ 1010023。 我们在1。5年的时间内多次收集了光学IZ和近红外J波段成像，以得出准确的三角视差和金属耗尽的超酷矮人候选候选Wise1810的正确运动。我们还获得了低分辨率光谱（0.6 $ - $ 1.0 $ $ m）和新的红外（0.9 $ - $ 1.3 $ 1.3 $ $ m）WISE1810的光谱，这些光谱与我们的光度法结合了我们的其他现有数据，来自文献的其他现有数据，并通过$ 1的整合$ 0.6，从观点分布中确定对象的光度。我们将完整的光学和红外光谱与最先进的大气模型进行了比较，以进一步限制其有效温度，表面重力和金属性。 Wise1810在$ iz $ bands中检测到$ i $ = 23.871 $ \ pm $ 0.104和$ z $ = 20.147 $ \ pm $ 0.083 mag在Panstarrs系统中。在任何一个$ z $ - 和$ j $ band滤波器中，它没有显示出任何明显的光度变异性，超过0.1 $ -0.2 mag。非常红色的$ z-j \约2.9美元的颜色与超酷矮人的性质兼容。适合视差和适当的运动，我们测量的三角视差为112.5 $^{+8.1} _ { - 8.0} $ MAS，WISE1810，仅将对象放置在8.9 $^{+0.7} _ { - 0.6} $ PC，比以前的三倍。我们采用了蒙特卡洛方法来估计视差和正确运动上的误差。对象的光度在log $ l/l_ \ odot $ = $ - $ 5.78 $ \ pm $ 0.11 dex确定。从比较与大气模型，我们可以推断出[Fe/H] $ \ \ -1.5 $的金属性可能比1000K的有效温度降低。 简略
Our goal is to characterise the physical properties of the metal-poor brown dwarf population. In particular, we focus on the recently discovered peculiar dwarf WISE J1810055$-$1010023. We collected optical iz and near-infrared J-band imaging on multiple occasions over 1.5 years to derive accurate trigonometric parallax and proper motion of the metal-depleted ultra-cool dwarf candidate WISE1810. We also acquired low-resolution optical spectroscopy (0.6$-$1.0 $μ$m) and new infrared (0.9$-$1.3 $μ$m) spectra of WISE1810 that were combined with our photometry, other existing data from the literature and our trigonometric distance to determine the object's luminosity from the integration of the observed spectral energy distribution covering from 0.6 through 16$μ$m. We compared the full optical and infrared spectrum with state-of-the-art atmosphere models to further constrain its effective temperature, surface gravity and metallicity. WISE1810 is detected in the $iz$ bands with AB magnitudes of $i$=23.871$\pm$0.104 and $z$=20.147$\pm$0.083 mag in the PanSTARRS system. It does not show any obvious photometric variability beyond 0.1$-$0.2 mag in any of the $z$- and $J$-band filters. The very red $z-J \approx 2.9$ mag colour is compatible with an ultra-cool dwarf nature. Fitting for parallax and proper motion, we measure a trigonometric parallax of 112.5$^{+8.1}_{-8.0}$ mas for WISE1810, placing the object at only 8.9$^{+0.7}_{-0.6}$ pc, about three times closer than previously thought. We employed Monte Carlo methods to estimate the error on the parallax and proper motion. The object's luminosity was determined at log$L/L_\odot$=$-$5.78$\pm$0.11 dex. From the comparison to atmospheric models, we infer a likely metallicity of [Fe/H] $\approx -1.5$ and an effective temperature cooler than 1000K. Abridged
