翼宿（Wings）之微点：来自层状宽线区（BLR）的指数型宽线

本文研究了韦布空间望远镜（JWST）发现的“小红点”和“小蓝点”中Halpha谱线轮廓所呈现的指数型宽翼特征。研究提出，这些特征可以通过径向分层的位力化宽线区模型来解释，而无需依赖电子散射作为主要的致宽机制。

arXiv:2604.04216v2 Announce Type: replace Abstract: We investigate the origin of the broad exponential wings seen in the Halpha profiles of many JWST-discovered little red dots (LRDs) and little blue dots (LBDs). Recent studies show that exponential broad-line profiles are not unique to LRDs, are common in LBDs too, and need not imply that electron scattering is the dominant broadening mechanism in every source. Motivated by our unification picture, in which LRDs are dust-reddened, high-inclination counterparts of compact blue broad-line AGNs, we model the broad Balmer emission with a virialized, radially stratified broad-line region (BLR). In this framework, the observed profile is the luminosity-weighted superposition of clouds spanning a range of radii, and hence virial velocities. We show that a stratified BLR reproduces the exponential-like wings observed in three representative LRDs and one LBD, without requiring electron scattering as the dominant broadening mechanism. For the LBD GS-3073, the same BLR -- calibrated only to Halpha -- predicts, parameter-free, that He II 4686 and Hbeta should be broader than Halpha, consistent with observations and offering an independent test of BLR ionization stratification. Our results support a picture in which wings and cores encode different physics: the wings arise primarily from virial BLR