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arXiv 1107.5809astro-ph.EPastro-ph.GA
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第二代微透镜行星巡天：真实模拟

Second-generation microlensing planet surveys: a realistic simulation

Yossi Shvartzvald, Dan Maoz

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11 pages, 9 figures, 1 table, MNRAS, in press
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摘要：

迄今为止，微透镜巡天已经发现了大约12颗太阳系外行星，主要集中在少数高倍透镜事件上，这些事件对行星探测具有很高的灵敏度。相反，最近开始的第二代实验也持续监测大多数低放大率事件。我们进行了一个现实的数值模拟这样的实验。我们模拟缩放，太阳，八行星系统，研究各种物理参数（行星频率，雪线与恒星质量R_snow ~ M^s的缩放），并折叠在各种观测参数（节奏，实验持续时间），采样序列和测光误差分布从真正的正在进行的实验。我们量化了探测到的行星产量对节奏和实验持续时间的依赖性，例如，当从3小时到15分钟的基线节奏，或从80天到150天的实验时，产量翻了一番。雪线尺度指数s和行星系的丰度之间存在简并性，这可以从我们的尺度太阳模拟模型的实验中推断出来。4年后，正在进行的第二代实验将发现大约50颗行星，因此将能够确定雪线行星出现的频率，精确度为10- 30%，假设拥有此类行星的恒星比例在1/3和1/10之间，雪线指数在s=0.5到2之间。如果大多数行星系都是太阳系类似物，那么超过65%的被探测行星将是“类星体”，六分之五的被探测异常将是由于一颗行星，六分之一的异常将在一次透镜事件中揭示两颗行星。

英文摘要：

Microlensing surveys, which have discovered about a dozen extrasolar planets to date, have focused on the small minority of high-magnification lensing events, which have a high sensitivity to planet detection. In contrast, second-generation experiments, of the type that has recently begun, monitor continuously also the majority of low-magnification events. We carry out a realistic numerical simulation of such experiments. We simulate scaled, solar-like, eight-planet systems, studying a variety of physical parameters (planet frequency, scaling of the snowline with stellar mass R_snow ~ M^s), and folding in the various observational parameters (cadence, experiment duration), with sampling sequences and photometric error distributions taken from the real ongoing experiment. We quantify the dependence of detected planet yield on cadence and experiment duration, e.g., the yield is doubled when going from 3-hour to 15-minute baseline cadences, or from an 80-day-long to a 150-day-long experiment. There is a degeneracy between the snowline scaling index s and the abundance of planetary systems that can be inferred from the experiment, in the context of our scaled solar-analog model. After 4 years, the ongoing second-generation experiment will discover of the order of 50 planets, and thus will be able to determine the frequency of snowline planet occurrence to a precision of 10-30%, assuming the fraction of stars hosting such planets is between 1/3 and 1/10, and a snowline index in the range s=0.5 to 2. If most planetary systems are solar analogs, over 65% of the detected planets will be "Jupiters", five in six of the detected anomalies will be due to a single planet, and one in six will reveal two planets in a single lensing event.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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