Irregular Dust Features around Intermediate-mass Young Stars with GPI: Signs of Youth or Misaligned Disks?
Irregular Dust Features around Intermediate-mass Young Stars with GPI: Signs of Youth or Misaligned Disks?
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DOI：
10.3847/1538-4357/ab59e2
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发表时间：
2019-11
期刊：
影响因子：
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通讯作者：
A. Laws;T. Harries;B. Setterholm;J. Monnier;Evan A. Rich;A. Aarnio;F. Adams;S. Andrews;J. Bae-J.
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文献类型：
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作者：
A. Laws;T. Harries;B. Setterholm;J. Monnier;Evan A. Rich;A. Aarnio;F. Adams;S. Andrews;J. Bae-J.
我们正在使用双子座行星成像仪(GPI)对30多个星盘进行大规模调查，以确定观察到的尘埃结构是否与光谱能量分布预测相符，并与恒星性质有任何关联。GPI可以使用带有日冕和自适应光学的高分辨率偏振差分成像技术来观测星周环境中的尘埃散射的近红外光。这些数据是在两年多的时间里在J和H波段获得的，内工作角分别为0.“08和0.”11。在完整的观测结果公布之前，我们在这里展示了五个在中央恒星2“范围内具有延伸的和不规则的尘埃结构的天体。这些天体是福日、MWC789、HD 45677、母鸡3-365和HD 139614。观测到的结构与每个物体都是带有原行星尘埃的前主序列恒星一致。这五个天体的恒星周围环境可能是极端年轻和复杂的初始条件造成的，可能是由于未对准的圆盘投射的阴影造成的不对称散射模式，或者在某些情况下是由于与伴星的相互作用造成的。我们在大多数物体中看到复杂的U-ϕ结构，这可能表明多次散射或由伴星的照明造成的。具体的关键发现包括MWC789的第一次高对比度观测，揭示了新发现的伴星和弧线，以及在亨氏3-365附近的两个微弱的伴星。这两个对象应该进一步观察，以确认同伴候选人是否正在到来。需要进一步的观察和建模来确定结构的原因。
We are undertaking a large survey of over 30 disks using the Gemini Planet Imager (GPI) to see whether the observed dust structures match spectral energy distribution predictions and have any correlation with stellar properties. GPI can observe near-infrared light scattered from dust in circumstellar environments using high-resolution Polarimetric Differential Imaging with coronagraphy and adaptive optics. The data have been taken in the J and H bands over two years, with inner working angles of 0.″08 and 0.″11, respectively. Ahead of the release of the complete survey results, here we present five objects with extended and irregular dust structures within 2″ of the central star. These objects are FU Ori, MWC 789, HD 45677, Hen 3-365, and HD 139614. The observed structures are consistent with each object being a pre-main-sequence star with protoplanetary dust. The five objects’ circumstellar environments could result from extreme youth and complex initial conditions, from asymmetric scattering patterns due to shadows cast by misaligned disks, or in some cases from interactions with companions. We see complex Uϕ structures in most objects that could indicate multiple scattering or result from the illumination of companions. Specific key findings include the first high-contrast observation of MWC 789 revealing a newly discovered companion candidate and arc, and two faint companion candidates around Hen 3-365. These two objects should be observed further to confirm whether the companion candidates are comoving. Further observations and modeling are required to determine the causes of the structures.