论文标题
恒星风会影响碎屑磁盘中的气体动态，并创建可观察的皮带风
Stellar winds can affect gas dynamics in debris disks and create observable belt winds
论文作者
论文摘要
上下文：现在在许多年龄在10 Myr到$ \ sim $ \ sim $ 1 GYR之间的成熟恒星周围的许多外部系统中检测到气体，并带有行星皮带。这些成熟的磁盘中的气体被认为是从行星中释放出来的，并已使用粘性磁盘方法进行建模。在低密度下，这可能不是一个很好的假设，因为恒星风可以吹出气体。 方法：我们开发了一种到M恒星的分析模型，该模型可以跟随气体流出的演变和目标在磁盘或风之间发生过渡时。至关重要的标准是气体密度，气体颗粒不再受到远距离轨迹的恒星风质子的影响。 结果：我们发现：1）径向宽度$ΔR$带有气体密度$ <7 \，（Δr/50 {\ rm \，au}）^{ - 1} $ cm $^{ - 3} $会产生风盘而不是磁盘，这将解释最近流出的气体检测。 2）该皮带风的特性可用于测量恒星风能，例如它们的密度和速度。 3）较低的分数发光性$ f $的碎屑盘更有可能产生气体，这可以通过当前设施观察到。 结论：包含诸如Fomalhaut或TWA 7或更一般的气体质量的系统，具有分数发光度的碎屑均为$ f \ f \ sillsim 10^{ - 5}（l_ \ star/l_ \ odot） （或皮带风）比气盘。在年轻系统中，观察到的气体以高速流出流出，没有LUP可以是这种皮带风的一个例子。 ALMA（CO和CO $^+$可能是良好的风示踪剂）可以检测到这些气风，并且将使我们能够限制主要序列恒星的恒星风质，否则这些恒星很难测量。
Context: Gas is now detected in many extrasolar systems around mature stars aged between 10 Myr to $\sim$ 1 Gyr with planetesimal belts. Gas in these mature disks is thought to be released from planetesimals and has been modelled using a viscous disk approach. At low densities, this may not be a good assumption as the gas could be blown out by the stellar wind instead. Methods: We developed an analytical model for A to M stars that can follow the evolution of gas outflows and target when the transition occurs between a disk or a wind. The crucial criterion is the gas density for which gas particles stop being protected from stellar wind protons impacting at high velocities on radial trajectories. Results: We find that: 1) Belts of radial width $ΔR$ with gas densities $< 7 \, (ΔR/50 {\rm \, au})^{-1}$ cm$^{-3}$ would create a wind rather than a disk, which would explain the recent outflowing gas detection in NO Lup. 2) The properties of this belt wind can be used to measure stellar wind properties such as their densities and velocities. 3) Debris disks with low fractional luminosities $f$ are more likely to create gas winds, which could be observed with current facilities. Conclusions: The systems containing low gas masses such as Fomalhaut or TWA 7 or more generally, debris disks with fractional luminosities $f \lesssim 10^{-5} (L_\star/L_\odot)^{-0.37} $ or stellar luminosity $\gtrsim 20 \, L_\odot$ (A0V or earlier) would rather create gas outflows (or belt winds) than gas disks. Gas observed to be outflowing at high velocity in the young system NO Lup could be an example of such belt winds. The detection of these gas winds is possible with ALMA (CO and CO$^+$ could be good wind tracers) and would allow us to constrain the stellar wind properties of main-sequence stars, which are otherwise difficult to measure.
