发表机构
Washington University（华盛顿大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文预测罗曼望远镜GBTDS巡天通过凌星和相位曲线通道探测白矮星系外行星的产量，发现木星大小行星为主，源混合是主要挑战，零探测可约束发生率。
AI 中文摘要
白矮星（WD）因其行星与恒星尺寸比大，为探测和描述系外行星提供了无与伦比的机会。然而，迄今为止仅确认了一颗凌星白矮星系外行星，且由于白矮星系外行星的快速凌星和微弱的相位曲线调制需要高精度、高节奏测光，其发生率约束仍然宽松。南希·格雷斯·罗曼太空望远镜的银河系核球时域巡天（GBTDS）将以12.1分钟的节奏观测数千颗白矮星，恰好提供此类观测。该巡天预期的白矮星系外行星产量尚未量化。在此，我们预测GBTDS在最初三个高节奏季节中通过凌星和非凌星（相位曲线）通道的白矮星系外行星产量。我们针对Besançon合成白矮星种群，在行星半径、轨道周期和宿主属性的网格上运行蒙特卡洛探测概率模拟。木星大小的行星主导凌星产量，其周期平均有效巡天规模为$\overline{N}_\mathrm{eff}\approx8$，要求底层发生率$\overline{\eta}_1\approx12\\%$才能获得一次预期探测；其次是海王星大小行星，$\overline{N}_\mathrm{eff}\approx2.6$（$\overline{\eta}_1\approx38\\%$）；亚海王星大小行星，$\overline{N}_\mathrm{eff}\approx1.8$（$\overline{\eta}_1\approx55\\%$）。源混合是拥挤的GBTDS视场中的主要观测挑战，消除了原始预测产量的约95%。相位曲线提供边缘探测，最多增加约4%的凌星产量。GBTDS的零探测将以95%置信度将木星大小行星的$\eta_\mathrm{WD}$限制在$<28\\%$。GBTDS将提供太阳邻域之外的首个白矮星系外行星发生率约束，并为未来表征确定主要目标。
英文摘要
White dwarfs (WDs) provide an unparalleled opportunity for detecting and characterizing exoplanets because of the large planet-to-star size ratio. However, only one transiting WD exoplanet is confirmed to date, and occurrence rate constraints remain loose because the rapid transits and weak phase curve modulations of WD exoplanets require high-precision, high-cadence photometry. The Galactic Bulge Time Domain Survey (GBTDS) of the Nancy Grace Roman Space Telescope will provide exactly this by observing thousands of WDs at 12.1-minute cadence. The expected WD exoplanet yield of this survey is not yet quantified. Here, we predict the GBTDS WD exoplanet yield over its first three high-cadence seasons, through both transiting and non-transiting (phase curve) channels. We run Monte Carlo detection probability simulations over a grid of planet radius, orbital period, and host properties for a Besançon synthetic population of WDs. Jupiter-sized planets dominate the transit yield, with a period-averaged effective survey size of $\overline{N}_\mathrm{eff}\approx8$, requiring an underlying occurrence rate of $\overlineη_1\approx12\%$ for one expected detection, followed by $\overline{N}_\mathrm{eff}\approx2.6$ ($\overlineη_1\approx38\%$) for Neptune-sized and $\overline{N}_\mathrm{eff}\approx1.8$ ($\overlineη_1\approx55\%$) for sub-Neptune-sized planets. Source blending is the major observational challenge in the crowded GBTDS fields, removing $\approx95\%$ of the raw predicted yield. Phase curve provides marginal detections, adding at most $\approx4\%$ to the transit yield. A null detection by GBTDS would constrain $η_\mathrm{WD}$ to $< 28\%$ for Jupiter-sized planets at $95\%$ confidence. GBTDS will deliver the first WD exoplanet occurrence-rate constraints beyond the solar neighborhood and identify prime targets for future characterization.
Comments30 pages, 14 figures, 3 tables, submitted to the AAS journals
