Title: A practicable estimation of opening angle of dust torus in Type-1.9 AGN with double-peaked broad H$α$ Show Chinese title

Title: A practicable estimation of opening angle of dust torus in Type-1.9 AGN with double-peaked broad H$α$

Abstract: In this manuscript, an independent method is proposed to estimate opening angle of dust torus in AGN, through unique properties of Type-1.9 AGN with double-peaked broad H$\alpha$ (Type-1.9 DPAGN) coming from central accretion disk. Type-1.9 AGN without broad H$\beta$ can be expected by the commonly accepted unified model of AGN, considering central BLRs seriously obscured by dust torus with its upper boundary in the line of sight. For the unique Type-1.9 DPAGN, accretion disk originations of double-peaked broad H$\alpha$ can be applied to determine the inclination angle of the central accretion disk, which is well accepted as substitute of the half opening angle of the central dust torus. Then, among low redshift Type-1.9 DPAGN in SDSS, SDSS J1607+3319 at redshift 0.063 is collected, and the half opening angle of the central dust torus is determined to be around 46$\pm$4\degr, after considering disfavoured BBH system to explain the double-peaked broad H$\alpha$ through long-term none variabilities and disfavoured local physical conditions to explain disappearance of broad H$\beta$ through virial BH mass properties. The results indicate that more detailed studying on dust torus of AGN can be appropriately done through Type-1.9 DPAGN in the near future. Show Chinese abstract

Abstract: 本文提出了一种独立的方法，通过来自中心吸积盘的双峰宽H$\alpha$（1.9型双峰AGN）的独特性质来估算活动星系核（AGN）中的尘埃环张开角度。根据广泛接受的AGN统一模型，可以预期没有宽H$\beta$的1.9型AGN，考虑到来自视线方向的尘埃环严重遮挡其中央BLRs（宽带发射线区）。 对于独特的1.9型双峰AGN，双峰宽H$\alpha$的吸积盘起源可以用来确定中心吸积盘的倾角，这被广泛接受为中央尘埃环半张开角的替代物。 然后，在低红移的SDSS 1.9型双峰AGN中，红移为0.063的SDSS J1607+3319被收集，并且在考虑了不支持的BBH系统来解释双峰宽H$\alpha$的长期非变异性以及不支持的局部物理条件来解释宽H$\beta$的消失后，确定中心尘埃环的半张开角约为46$\pm$4\degr 。 结果表明，未来可以通过研究1.9型双峰AGN更详细地研究AGN中的尘埃环。