论文标题
在开普勒场中的晚期矮人恒星及其对行星形成的影响，小星体发生的小星体出现增加了金属性。
An Increase in Small-planet Occurrence with Metallicity for Late-type Dwarf Stars in the Kepler Field and Its Implications for Planet Formation
论文作者
论文摘要
虽然众所周知，巨型行星的发生随着宿主恒星的金属性而迅速上升，但尚不清楚围绕晚期型矮人恒星周围的小风扇是否依赖于宿主星形金属性。使用开普勒数据发布25个行星候选列表及其完整性数据产品，我们探索了行星的出现，这是Kepler Field的后期型矮人矮人恒星种群中金属性的函数。我们发现，所有行星Radii $ r _ {\ Mathrm {p}} $的行星发生随着金属性而增加，至少至少$ r _ {\ Mathrm {p}} \ 2〜r _ {\ oplus} $，以及在范围内r _ {\ mathrm {p}} \ Lessim 5〜r _ {\ oplus} $ Planet出现与金属性$ z $线性缩放。推断我们的结果，我们预测，用$ r _ {\ mathrm {p}} \ Lessim 2〜R _ {\ oplus} $的短期行星{\ oplus} $在早期的M dwarf星星周围很少见，$ \ mathrm {[m/h]} $ \ mathrm {[m/h]} \ sillesim+0.0 $。在开普勒场中观察到的行星发生对金属性的这种依赖性强调了在估计星球发生的后期矮人恒星中需要控制金属性的必要性，例如Kepler的K2膨胀和传播的外部射击测量卫星（Tess）。我们证实了理论上的期望，即小星球的出现 - 低质量恒星的主恒星金属关系比太阳能恒星更强。我们确定，开普勒场中晚期矮人周围的行星中的预期固体质量与其原星磁盘中的行星制造固体总量相当。我们认为，这种高效率的行星形成有利于行星的积聚，而不是卵石积聚，因为Kepler围绕晚期矮人恒星观察到的小行星的起源。
While it is well established that giant-planet occurrence rises rapidly with host star metallicity, it is not yet clear if small-planet occurrence around late-type dwarf stars depends on host star metallicity. Using the Kepler Data Release 25 planet candidate list and its completeness data products, we explore planet occurrence as a function of metallicity in the Kepler field's late-type dwarf stellar population. We find that planet occurrence increases with metallicity for all planet radii $R_{\mathrm{p}}$ down to at least $R_{\mathrm{p}}\approx2~R_{\oplus}$ and that in the range $2~R_{\oplus}\lesssim R_{\mathrm{p}}\lesssim 5~R_{\oplus}$ planet occurrence scales linearly with metallicity $Z$. Extrapolating our results, we predict that short-period planets with $R_{\mathrm{p}}\lesssim 2~R_{\oplus}$ should be rare around early M dwarf stars with $\mathrm{[M/H]}\lesssim-0.5$ or late M dwarf stars with $\mathrm{[M/H]}\lesssim+0.0$. This dependence of planet occurrence on metallicity observed in the Kepler field emphasizes the need to control for metallicity in estimates of planet occurrence for late-type dwarf stars like those targeted by Kepler's K2 extension and the Transiting Exoplanet Survey Satellite (TESS). We confirm the theoretical expectation that the small planet occurrence--host star metallicity relation is stronger for low-mass stars than for solar-type stars. We establish that the expected solid mass in planets around late-type dwarfs in the Kepler field is comparable to the total amount of planet-making solids in their protoplanetary disks. We argue that this high efficiency of planet formation favors planetesimal accretion over pebble accretion as the origin of the small planets observed by Kepler around late-type dwarf stars.
