当前位置: X-MOL 学术Astron. J. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Large Adaptive Optics Survey for Substellar Objects around Young, Nearby, Low-mass Stars with Robo-AO
The Astronomical Journal ( IF 5.1 ) Pub Date : 2021-08-13 , DOI: 10.3847/1538-3881/ac0445
Massa Salama 1 , James Ou 1 , Christoph Baranec 1 , Michael C. Liu 2 , Brendan P. Bowler 3 , Paul Barnes 1 , Morgan Bonnet 2 , Mark Chun 1 , Dmitry A. Duev 4 , Sean Goebel 1 , Don Hall 1 , Shane Jacobson 1 , Rebecca Jensen-Clem 5 , Nicholas M. Law 6 , Charles Lockhart 1 , Reed Riddle 4 , Heather Situ 2 , Eric Warmbier 1 , Zhoujian Zhang 2
Affiliation  

We present results from the Large Adaptive optics Survey for Substellar Objects, where the goal is to directly image new substellar companions (<70 M Jup) at wide orbital separations (≳50 au) around young (≲300 Myr), nearby (<100 pc), low-mass (≈0.1–0.8 ${M}_{\odot }$) stars. We report on 427 young stars imaged in the visible (i′) and near-infrared (J or H ) simultaneously with Robo-AO on the Kitt Peak 2.1 m telescope and later the Maunakea University of Hawaii 2.2 m telescope. To undertake the observations, we commissioned a new infrared camera for Robo-AO that uses a low-noise high-speed SAPHIRA avalanche photodiode detector. We detected 121 companion candidates around 111 stars, of which 62 companions are physically associated based on Gaia DR2 parallaxes and proper motions, another 45 require follow-up observations to confirm physical association, and 14 are background objects. The companion separations range from 2 to 1101 au and reach contrast ratios of 7.7 mag in the near-infrared compared to the primary. The majority of confirmed and pending candidates are stellar companions, with ∼5 being potentially substellar and requiring follow-up observations for confirmation. We also detected a 439 M Jup and an 815 M Jup companion that were previously reported. We found 34 of our targets have acceleration measurements detected using Hipparcos–Gaia proper motions. Of those, ${58}_{-14}^{+12}$% of the 12 stars with imaged companion candidates have significant accelerations (${\chi }^{2}\gt 11.8$), while only ${23}_{-6}^{+11}$% of the remaining 22 stars with no detected companion have significant accelerations. The significance of the acceleration decreases with increasing companion separation. These young accelerating low-mass stars with companions will eventually yield dynamical masses with future orbit monitoring.



中文翻译:

使用 Robo-AO 对年轻、附近、低质量恒星周围的亚恒星物体进行大型自适应光学巡天

我们展示了亚星天体大型自适应光学调查的结果,目标是直接成像新的亚星伴星(<70 M Jup)在年轻(≲ 300 Myr)周围的宽轨道间隔(≳50 au),附近(<100 pc), 低质量 (≈0.1–0.8 ${M}_{\odot }$) 星。我们报告了 427 颗在可见光(i ′ )和近红外(JH) 同时与 Kitt Peak 2.1 m 望远镜上的 Robo-AO 以及后来的夏威夷莫纳基亚大学 2.2 m 望远镜上的 Robo-AO 一起使用。为了进行观测,我们为 Robo-AO 委托了一台新的红外摄像机,该摄像机使用低噪声高速 SAPHIRA 雪崩光电二极管探测器。我们在 111 颗恒星周围检测到 121 个伴星候选,其中 62 个伴星基于 Gaia DR2 视差和自行进行物理关联,另外 45 个需要后续观测以确认物理关联,14 个是背景天体。伴随分离的范围从 2 到 1101 au,与主分离相比,近红外波段的对比度达到 7.7 mag。大多数已确认和待定的候选者是恒星伴星,约 5 颗可能是亚恒星,需要后续观测进行确认。我们还检测到 439M Jup和之前报道的 815 M Jup同伴。我们发现我们的 34 个目标使用 Hipparcos-Gaia 自身运动检测到加速度测量值。其中,${58}_{-14}^{+12}$12 颗带有候选伴星的恒星​​中有 % 有明显的加速(${\chi }^{2}\gt 11.8$),而${23}_{-6}^{+11}$其余 22 颗未检测到伴星的恒星​​中只有% 有明显的加速。加速度的重要性随着同伴分离的增加而降低。这些带有伴星的年轻加速低质量恒星最终将通过未来的轨道监测产生动力学质量。

更新日期:2021-08-13
down
wechat
bug