中文

$\beta$ Pictoris 内盘的偏振光观测及 $\beta$ Pictoris b 的新轨道参数

地球与行星天体物理 2015-09-23 v1

摘要

我们展示了利用 Gemini Planet Imager (GPI) 偏振模式对 β\beta Pic 的 HH 波段观测结果,揭示了约 0.3 角秒(约 6 AU)至约 1.7 角秒(约 33 AU)之间的碎屑盘,同时探测到了 β\beta Pic bb。偏振盘图像采用尘埃密度模型结合 Henyey-Greenstein 散射相函数进行拟合。最佳拟合模型表明,该盘相对于视线倾斜(ϕ=85.27deg0.19+0.26\phi=85.27{\deg}^{+0.26}_{-0.19}),位置角 θPA=30.35deg0.28+0.29\theta_{PA}=30.35{\deg}^{+0.29}_{-0.28}(与主外盘 θPA29deg\theta_{PA}\approx29{\deg} 略有偏移),从内盘半径 23.60.6+0.923.6^{+0.9}_{-0.6} AU 延伸至远超 GPI 视场之外。此外,基于在 GPI 光谱模式下跨越 14 个月获取的新天体测量数据,我们给出了 β\beta Pic bb 的更新轨道。该行星的半长轴为 a=9.20.4+1.5a=9.2^{+1.5}_{-0.4} AU,偏心率 e0.26e\leq 0.26。升交点经度为 Ω=31.75deg±0.15\Omega=31.75{\deg}\pm0.15,与主外盘和 GPI 图像中看到的内盘均有偏移。轨道拟合将 β\beta Pic 的恒星质量约束为 1.60±0.05M1.60\pm0.05 M_{\odot}β\beta Pic bb 的动力学塑造难以解释推断出的盘属性的以下三个方面:1) 模型给出的盘内半径比由 β\beta Pic bb 造成的情况更远;2) 内盘与 β\beta Pic bb 之间的相互倾角为 4deg4{\deg},而预期应更接近于零;3) 盘的纵横比(h0=0.1370.006+0.005h_0 = 0.137^{+0.005}_{-0.006})大于由与 β\beta Pic bb 的相互作用或盘母体自激发所预期的值。

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引用

@article{arxiv.1508.04787,
  title  = {$\beta$ Pictoris' inner disk in polarized light and new orbital parameters for $\beta$ Pictoris b},
  author = {Maxwell A. Millar-Blanchaer and James R. Graham and Laurent Pueyo and Paul Kalas and Rebekah I. Dawson and Jason Wang and Marshall Perrin and Dae-Sik Moon and Bruce Macintosh and S. Mark Ammons and Travis Barman and Andrew Cardwell and Christine H. Chen and Eugene Chiang and Jeffrey Chilcote and Tara Cotten and Robert J. De Rosa and Zachary H. Draper and Jennifer Dunn and Gaspard Duchêne and Thomas M. Esposito and Michael P. Fitzgerald and Katherine B. Follette and Stephen J. Goodsell and Alexandra Z. Greenbaum and Markus Hartung and Pascale Hibon and Sasha Hinkley and Patrick Ingraham and Rebecca Jensen-Clem and Quinn Konopacky and James E. Larkin and Douglas Long and Jérôme Maire and Franck Marchis and Mark S. Marley and Christian Marois and Katie M. Morzinski and Eric L. Nielsen and David W. Palmer and Rebecca Oppenheimer and Lisa Poyneer and Abhijith Rajan and Fredrik T. Rantakyrö and Jean-Baptiste Ruffio and Naru Sadakuni and Leslie Saddlemyer and Adam C. Schneider and Anand Sivaramakrishnan and Remi Soummer and Sandrine Thomas and Gautam Vasisht and David Vega and J. Kent Wallace and Kimberly Ward-Duong and Sloane J. Wiktorowicz and Schuyler G. Wolff},
  journal= {arXiv preprint arXiv:1508.04787},
  year   = {2015}
}