Accretion Properties of PDS 70b with MUSE
Accretion Properties of PDS 70b with MUSE
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DOI：
10.3847/1538-3881/ab811e
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
J. Hashimoto;Y. Aoyama;M. Konishi;T. Uyama;S. Takasao;M. Ikoma;T. Tanigawa
中科院分区：
文献类型：
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作者：
J. Hashimoto;Y. Aoyama;M. Konishi;T. Uyama;S. Takasao;M. Ikoma;T. Tanigawa
我们报告了使用甚大望远镜/多装置光谱探测器获得的 PDS 70b 吸积特性的新评估。与Haffert等人之前的研究的主要区别在于。青山和生驹处于质量吸积率中。同时进行多线观测，例如 Hα 和 Hβ，可以更好地约束吸积行星的物理特性。虽然我们清楚地检测到 PDS 70b 中的 Hα 排放，但没有检测到 Hβ 排放。我们估计上限为 3σ 的 Hβ 的线通量为 2.3 × 10−16 erg s−1 cm−2。使用星际消光值，PDS 70b 的通量比 FHβ/FHα 为 2.0 星等。结合Hα线宽和Hα的去红线光度，我们推导出PDS 70b质量吸积率为≳5 × 10−7 MJup yr−1。 PDS 70b的质量吸积率比PDS 70大一个数量级。我们发现填充因子ff（发射Hα的行星表面的分数面积）为≳0.01，这与典型的恒星值相似。 ff 值较小表明 Hα 发射区域位于 PDS 70b 的表面。
We report a new evaluation of the accretion properties of PDS 70b obtained with the Very Large Telescope/Multi Unit Spectroscopic Explorer. The main difference from the previous studies of Haffert et al. and Aoyama & Ikoma is in the mass accretion rate. Simultaneous multiple line observations, such as Hα and Hβ, can better constrain the physical properties of an accreting planet. While we clearly detected Hα emissions from PDS 70b, no Hβ emissions were detected. We estimate the line flux of Hβ with a 3σ upper limit to be 2.3 × 10−16 erg s−1 cm−2. The flux ratio FHβ/FHα for PDS 70b is 2.0 mag using the interstellar extinction value. By combining with the Hα linewidth and the dereddening line luminosity of Hα, we derive the PDS 70b mass accretion rate to be ≳5 × 10−7 MJup yr−1. The PDS 70b mass accretion rate is an order of magnitude larger than that of PDS 70. We found that the filling factor ff (the fractional area of the planetary surface emitting Hα) is ≳0.01, which is similar to the typical stellar value. The small value of ff indicates that the Hα emitting areas are localized at the surface of PDS 70b.