Multi-epoch Direct Imaging and Time-variable Scattered Light Morphology of the HD 163296 Protoplanetary Disk
Multi-epoch Direct Imaging and Time-variable Scattered Light Morphology of the HD 163296 Protoplanetary Disk
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DOI：
10.3847/1538-4357/ab0f3b
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发表时间：
2018-11
期刊：
影响因子：
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通讯作者：
Evan A. Rich;J. Wisniewski;T. Currie;M. Fukagawa;C. Grady;M. Sitko;M. Pikhartova;J. Hashimoto
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文献类型：
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作者：
Evan A. Rich;J. Wisniewski;T. Currie;M. Fukagawa;C. Grady;M. Sitko;M. Pikhartova;J. Hashimoto
我们提出了H波段偏振散射光图像和JHK高对比度光谱的原行星盘周围的HD 163296观察与斯巴鲁天文台的高对比度冠状成像仪自适应光学（HiCIAO）和斯巴鲁Coronagraphic极端自适应光学（SCExAO）/Coronagraphic高角分辨率成像光谱仪（CHARIS）仪器。偏振图像分辨出HD 163296周围的一个断裂环结构，该结构在沿长轴沿着0.“65（66 Au）的距离处达到峰值，并沿长轴向外延伸至0.”98（沿着100 Au）。我们2011年的H波段数据显示出明显的轴对称性，磁盘的西北和东南侧显示出类似的强度。我们的数据与2016年甚大望远镜（VLT）/光谱偏振高对比度系外行星研究（SPHERE）的H波段观测明显不同，该观测发现圆盘的西北和东南侧之间存在强烈的2.7×不对称性。总的来说，这些结果表明存在时变，非方位对称照明的外盘。虽然我们的SCExAO/CHARIS数据足够敏感，可以在热红外（IR）中恢复从NIRC 2中识别的行星候选者，但我们未能检测到与JHK亮度名义上一致的物体。这表明候选者在JHK波段中比模型预测更暗，可能是由于来自盘或大气尘埃/云的消光，或者它是数据集/数据处理的伪影，例如残余斑点或部分减去的盘特征。假设标准的热启动演化模型和系统年龄为500万年，我们设置了新的，直接的质量限制的内部（外部）阿塔卡马大毫米/亚毫米阵列（阿尔马）预测的原行星候选人沿着的主要（次要）磁盘轴的1.5（2）兆焦耳。
We present H-band polarized scattered light imagery and JHK high-contrast spectroscopy of the protoplanetary disk around HD 163296 observed with the High-Contrast Coronographic Imager for Adaptive Optics (HiCIAO) and Subaru Coronagraphic Extreme Adaptive Optics (SCExAO)/Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) instruments at Subaru Observatory. The polarimetric imagery resolve a broken ring structure surrounding HD 163296 that peaks at a distance along the major axis of 0.″65 (66 au) and extends out to 0.″98 (100 au) along the major axis. Our 2011 H-band data exhibit clear axisymmetry, with the NW and SE side of the disk exhibiting similar intensities. Our data are clearly different from 2016 epoch H-band observations of the Very Large Telescope (VLT)/Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE), which found a strong 2.7× asymmetry between the NW and SE side of the disk. Collectively, these results indicate the presence of time-variable, non-azimuthally symmetric illumination of the outer disk. While our SCExAO/CHARIS data are sensitive enough to recover the planet candidate identified from NIRC2 in the thermal infrared (IR), we fail to detect an object with JHK brightness nominally consistent with this object. This suggests that the candidate is either fainter in JHK bands than model predictions, possibly due to extinction from the disk or atmospheric dust/clouds, or that it is an artifact of the data set/data processing, such as a residual speckle or partially subtracted disk feature. Assuming standard hot-start evolutionary models and a system age of 5 Myr, we set new, direct mass limits for the inner (outer) Atacama Large Millimeter/submillimeter Array (ALMA)-predicted protoplanet candidate along the major (minor) disk axis of of 1.5 (2) MJ.