Separating extended disc features from the protoplanet in PDS 70 using VLT/SINFONI
Separating extended disc features from the protoplanet in PDS 70 using VLT/SINFONI
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DOI：
10.1093/mnras/stz1232
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发表时间：
2019-05
影响因子：
4.8
通讯作者：
V. Christiaens;S. Casassus;O. Absil;F. Cantalloube;C. Gonzalez;Julien H. Girard;R. Ramirez;B. Pairet
中科院分区：
文献类型：
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作者：
V. Christiaens;S. Casassus;O. Absil;F. Cantalloube;C. Gonzalez;Julien H. Girard;R. Ramirez;B. Pairet
过渡盘是寻找原行星和研究行星盘相互作用的主要目标。我们目前的VLT/SINFONI观测PDS 70，过渡盘与最近声称嵌入原行星。我们利用我们的数据中存在的角度和光谱多样性，使用主成分分析（PCA）进行最佳PSF建模和减法。我们报告了PDS 70 B的重新检测，包括外盘边缘的前侧和远侧，以及环形间隙中几个扩展特征的检测。我们比较了光谱微分成像之前（PCA-SADI），和后（PCA-ASDI）角微分成像。我们的测试表明，PCA-SADI更好地恢复扩展功能，而PCA-ASDI是更敏感的点源。我们采用负假伴星（NEGFC）技术来推算伴星的天体测量，得到r = 193.5 ± 4.9mas，PA =158.7° ± 3.0°。我们使用NEGFC和ANDROMEDA来推断原行星的K波段分光光度法，发现结果与最近的VLT/SPHERE观测一致，除了他们在K2滤波器中的2018/02历元测量。最后，我们根据PCA-SADI/PCA-ASDI在Brγ线附近的修正（假设没有消光），导出了伴星吸积率的上限为B < 1.26 × 10^（−7）[5 M_（Jup）/M_B][R_B/R_（Jup）]M_（Jup）yr^（−1）.
Transition discs are prime targets to look for protoplanets and study planet–disc interactions. We present VLT/SINFONI observations of PDS 70, a transition disc with a recently claimed embedded protoplanet. We take advantage of the angular and spectral diversity present in our data for an optimal PSF modelling and subtraction using principal component analysis (PCA). We report the redetection of PDS 70 b, both the front and far side of the outer disc edge, and the detection of several extended features in the annular gap. We compare spectral differential imaging applied before (PCA-SADI), and after (PCA-ASDI) angular differential imaging. Our tests suggest that PCA-SADI better recovers extended features, while PCA-ASDI is more sensitive to point sources. We adapted the negative fake companion (NEGFC) technique to infer the astrometry of the companion, and derived r = 193.5 ± 4.9 mas and PA =158.7° ± 3.0°. We used both NEGFC and ANDROMEDA to infer the K-band spectro-photometry of the protoplanet, and found results consistent with recent VLT/SPHERE observations, except for their 2018/02 epoch measurement in the K2 filter. Finally, we derived an upper limit of Ṁb < 1.26 × 10^(−7) [5M_(Jup)/M_b][R_b/R_(Jup)]M_(Jup) yr^(−1) for the accretion rate of the companion based on an adaptation of PCA-SADI/PCA-ASDI around the Brγ line (assuming no extinction).