NICMOS Kernel-phase Interferometry. I. Catalogue of Brown Dwarfs Observed in F110W and F170M
NICMOS Kernel-phase Interferometry. I. Catalogue of Brown Dwarfs Observed in F110W and F170M
复制标题
NICMOS 核相位干涉测量。
DOI：
10.3847/1538-3881/ac88d3
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
A. Kraus
中科院分区：
文献类型：
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作者：
S. Factor;A. Kraus
填补直接成像和径向速度勘测之间探测的不足，将测试整个半长轴范围内的行星形成和（亚）恒星双星理论，将近距宽分离的气态巨星和亚恒星伴星的形成联系起来。直接探测近距离伴星是非常困难的：日冕仪和点扩散函数减法技术在 λ/D 衍射极限附近失效。我们提出了一种名为 Argus 的新微弱伴星检测管道，用于分析内核相位，这是一种干涉测量可观测值，类似于非冗余孔径掩模的闭合相位，但利用了完整的无遮挡望远镜孔径。我们通过对附近 114 个棕矮星（在七个不同的程序中观察到）的整个 HST/NICMOS F110W 和 F170M 图像档案进行伴随搜索，展示了该流程以及干涉测量的强大功能。我们的管道能够在经典衍射极限的一半处检测通量比低至 ∼102 的伴星。我们没有发现新的伴星，但恢复并完善了 19 个先前成像伴星（其中两个具有多个历元）的天体测量，并确认了先前的两个核相检测。我们讨论了该技术在未检测到先前确认或提议的同伴方面的局限性。我们提出对比曲线，使群体研究能够利用非检测，并证明该技术在经典成像技术无法实现的分离方面的优势。我们样本的二元部分 (ϵb=14.4−3.0+4.7 %) 与之前的二元调查一致，即使对更紧密分离的伴星也很敏感。
Filling out the dearth of detections between direct imaging and radial velocity surveys will test theories of planet formation and (sub)stellar binarity across the full range of semimajor axes, connecting formation of close- to wide-separation gas giants and substellar companions. Direct detection of close-in companions is notoriously difficult: coronagraphs and point-spread function subtraction techniques fail near the λ/D diffraction limit. We present a new faint companion detection pipeline called Argus that analyzes kernel phases, an interferometric observable analogous to closure phases from nonredundant aperture masking but utilizing the full unobscured telescope aperture. We demonstrate the pipeline, and the power of interferometry, by performing a companion search on the entire HST/NICMOS F110W and F170M image archive of 114 nearby brown dwarfs (observed in seven different programs). Our pipeline is able to detect companions down to flux ratios of ∼102 at half the classical diffraction limit. We discover no new companions, but recover and refine astrometry of 19 previous imaging companions (two with multiple epochs) and confirm two previous kernel-phase detections. We discuss the limitations of this technique with respect to nondetections of previously confirmed or proposed companions. We present contrast curves to enable population studies to leverage nondetections and to demonstrate the strength of this technique at separations inaccessible to classical imaging techniques. The binary fraction of our sample ( ϵb=14.4−3.0+4.7 %) is consistent with previous binary surveys, even with sensitivity to much tighter separation companions.