AI 中文总结
该研究提出以恒星像差为新探针，利用 TESS 数据可探测广阔参数空间内的致密暗物质亚晕，为暗物质亚结构研究开辟了新途径。
AI 中文摘要
小尺度暗物质（DM）结构编码了暗物质粒子性质的关键信息，因此为竞争模型提供了灵敏的检验，但它仍未被电磁巡天直接探测，只能通过引力效应推断。恒星像差是观测者运动引起的光源视位置偏移，提供了一个尚未充分探索的探测此类信号的通道；暗物质亚晕可扰动观测者运动，在天球上留下空间相关的特征性恒星位置偏移。本文表明，凌日系外行星巡天卫星（TESS）凭借其长时标基线、宽天区覆盖和高 cadence 观测，非常适合搜寻这类像差信号。我们推导了基于费希尔矩阵的恒定观测者加速度灵敏度估计，预测从 TESS 星等 Tmag≤10 的组合样本中可达到低至 6.3×10⁻⁹ m/s² 的灵敏度，该灵敏度使 TESS 能在广阔参数空间内探测致密暗物质亚晕，范围从 AU 尺度距离处的 ≳10⁻⁶ M⊙ 到 O(10 pc) 处的 ≳10⁷ M⊙。TESS 的扇区观测策略还为潜在暗物质诱导的像差信号提供了固有时间分辨率。此外，我们简要讨论了未来数据分析的挑战，包括仪器系统误差和恒星天体测量前景（如视差和自行）的建模。我们的结果确立了恒星像差作为暗物质亚结构的新型探针，为 TESS 和下一代宽场巡天的专项搜寻铺平了道路。
英文摘要
Small-scale dark matter (DM) structure encodes key information about the particle nature of DM and therefore provides a sensitive test of competing models. Yet, it remains hidden from electromagnetic surveys and is instead inferred through its gravitational effects. Stellar aberration, the apparent shift in a light source's position induced by the observer's motion, offers a largely unexplored channel to access such signatures. DM subhalos can perturb the observer's motion, imprinting characteristic, spatially correlated shifts in stellar positions across the sky. We show that the Transiting Exoplanet Survey Satellite (TESS), with its long temporal baseline, wide sky coverage, and high-cadence observations, is well suited to search for these aberration signals. We derive Fisher-matrix-based sensitivity estimates for constant observer accelerations, forecasting a sensitivity down to $6.3\times 10^{-9}\,\mathrm{m/s^2}$ from the combined sample of TESS stars with magnitude $\mathrm{Tmag}\leq 10$. This sensitivity allows TESS to probe concentrated DM subhalos over a broad parameter space, from $\gtrsim 10^{-6}\,\mathrm{M_{\odot}}$ at AU-scale distances to $\gtrsim 10^{7}\,\mathrm{M_{\odot}}$ at $\mathcal{O}(10\,\mathrm{pc})$. TESS's sector-based observing strategy further provides intrinsic temporal resolution of potential DM-induced aberration signals. Moreover, we briefly discuss challenges for future data analysis, including the modeling of instrumental systematics and stellar astrometric foregrounds, such as parallax and proper motion. Our results establish stellar aberration as a novel probe of DM substructure, paving the way for dedicated searches in TESS and next-generation wide-field surveys.
Comments10 pages, 4 figures
