论文标题
PDS 70B与Muse的增生特性
Accretion Properties of PDS 70b with MUSE
论文作者
论文摘要
我们报告了对使用VLT/Muse获得的PDS 〜70B的积聚属性的新评估。与Haffert等人先前的研究的主要区别。 （2019）和Aoyama＆Ikoma（2019）的质量增生率。同时进行多个线观测，例如H $α$和H $β$，可以更好地限制吸积行星的物理特性。虽然我们清楚地检测到pds〜70b的H $α$排放，但未检测到H $β$排放。我们估计h $β$的线通量，其中3- $σ$上限为2.3〜 $ \ times $ 〜10 $^{ - 16} $ 〜ERG〜S $^s $^{ - 1} $ 〜cm $^{ - 2} $。 pds〜70b的通量比$ f _ {\ rmhβ} $/$ f _ {\ rmhα} $是$ <$〜$ 〜0.28。 Aoyama等人的数值研究。 （2018）建议$ f _ {\ rmhβ} $/$ f _ {\ rmhα} $如果灭绝可以忽略不计，则应接近统一。我们将通量比的降低归因于灭绝，并估计PDS〜70B的h $α$（$ a _ {\ rmhα} $）的灭绝是使用星际灭绝值为$> $ 〜2.0〜MAG。 ％在PDS 〜70b位置的原球磁盘间隙中预期的$ a _ {\ rmHα} $值为2.4〜MAG，这与估计的灭绝是一致的。通过与H $α$的H $α$ linewidth和DEDDENDING LINE亮度相结合，我们可以得出PDS 〜70B 〜70B的动态质量和质量增生率，为\ hashimotor {12〜 $ \ pm 〜3〜 $ 〜3〜 $ m _ $ \ gtrsim $ 〜5〜 $ \ times $ 〜10 $^{ - 7} $〜$ m _ {\ rm jup} $ 〜yr $^{ - 1} $，分别。我们将pds〜70b质量积聚率定为$ \ gtrsim $ 〜5〜 $ \ times $ 〜10 $^{ - 7} $〜$ m _ {\ rm jup} $ 〜yr $^yr $^{ - 1} $。 PDS〜70B质量积聚率的数量级大于PDS 〜70。我们发现，填充因子$ f _ {\ rm f} $（行星表面发射h $α$的分数区域）为$ \ gtrsim $ 0.01，类似于典型的恒星值。 $ f _ {\ rm f} $的小价值表示H $α$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 VLT/MUSE. The main difference from previous studies in Haffert et al. (2019) and Aoyama & Ikoma (2019) is in the mass accretion rate. Simultaneous multiple line observations, such as H$α$ and H$β$, can better constrain the physical properties of an accreting planet. While we clearly detected H$α$ emissions from PDS~70b, no H$β$ emissions were detected. We estimate the line flux of H$β$ with a 3-$σ$ upper limit to be 2.3~$\times$~10$^{-16}$~erg~s$^{-1}$~cm$^{-2}$. The flux ratio $F_{\rm Hβ}$/$F_{\rm Hα}$ for PDS~70b is $<$~0.28. Numerical investigations by Aoyama et al. (2018) suggest that $F_{\rm Hβ}$/$F_{\rm Hα}$ should be close to unity if the extinction is negligible. We attribute the reduction of the flux ratio to the extinction, and estimate the extinction of H$α$ ($A_{\rm Hα}$) for PDS~70b to be $>$~2.0~mag using the interstellar extinction value. %The expected $A_{\rm Hα}$ value in the gap of the protoplanetary disk at the PDS~70b location is 2.4~mag, which is consistent with the estimated extinction. By combining with the H$α$ linewidth and the dereddening line luminosity of H$α$, %we derive the PDS~70b dynamical mass and mass accretion rate to be \hashimotor{12~$\pm$~3~$M_{\rm Jup}$} and $\gtrsim$~5~$\times$~10$^{-7}$~$M_{\rm Jup}$~yr$^{-1}$, respectively. we derive the PDS~70b mass accretion rate to be $\gtrsim$~5~$\times$~10$^{-7}$~$M_{\rm Jup}$~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 $f_{\rm f}$ (the fractional area of the planetary surface emitting H$α$) is $\gtrsim$0.01, which is similar to the typical stellar value. The small value of $f_{\rm f}$ indicates that the H$α$ emitting areas are localized at the surface of PDS~70b.
