发表机构
Università degli Studi di Milano-Bicocca; University of Cambridge; University College London（米兰比可卡大学; 剑桥大学; 伦敦大学学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出尘埃遮蔽高倾角超爱丁顿吸积模型，定量解释小红点类似体SDSS J1025+1402的偏振观测，展示分光偏振测量作为探测吸积流几何的探针。
AI 中文摘要
近期对本地小红点（LRD）类似体SDSS~J1025+1402的观测揭示，其光学连续谱在约1.5%的水平上被偏振，而宽Hα谱线具有较低的偏振（约0.7%）和不同的偏振角。我们在一个情景中解释这些性质，其中LRDs是尘埃遮蔽的小蓝点（LBDs），在高倾角下观测，并由超爱丁顿吸积提供能量。在此框架下，几何厚内吸积流中的电子散射产生内禀连续谱偏振，而外薄盘的未偏振发射稀释了信号，尤其在光学波段。环核尘埃屏对连续谱和宽线发射均贡献二向色偏振。宽Hα缺乏内禀盘成分，因此具有较低的偏振和不同的位置角。我们表明该模型定量重现了观测到的偏振性质，尽管吸积率与倾角之间存在简并。这些结果展示了分光偏振测量作为探测小点族中吸积流几何和取向的探针的潜力，与光谱能量分布拟合和谱线诊断互补。
英文摘要
Recent observations of the local Little Red Dot (LRD) analog SDSS~J1025+1402 have revealed that the optical continuum is polarized at the ~1.5% level, while broad Halpha has lower polarization (~0.7%) and a different polarization angle. We explain these properties in a scenario in which LRDs are dust-obscured Little Blue Dots (LBDs) viewed at high inclination and powered by super-Eddington accretion. In this framework, electron scattering in the geometrically thick inner accretion flow produces intrinsic continuum polarization, while unpolarized emission from the outer thin disk dilutes the signal, particularly at optical wavelengths. A circumnuclear dust screen contributes dichroic polarization to both the continuum and broad-line emission. Broad Halpha lacks the intrinsic disk component and therefore has lower polarization and a different position angle. We show that this model quantitatively reproduces the observed polarization properties, although degeneracies between accretion rate and inclination remain. These results illustrate the potential of spectropolarimetry as a probe of accretion-flow geometry and orientation in the little-dot population, complementary to spectral-energy-distribution fitting and line diagnostics.
Comments12 pages, 6 figures, submitted
