标题： 电离气体在星系合并中观测到的外流速度的尘埃消光的明显效应 显示英文标题

标题： Apparent effect of dust extinction on the observed outflow velocity of ionized gas in galaxy mergers

摘要： 在本研究中，我们考察了星系合并晚期的光致电离外流，特别关注观测到的外流气体速度与尘埃消光明显效应之间的关系。 我们使用了N体/平滑粒子流体动力学（SPH）代码ASURA进行星系合并模拟。 这些模拟集中在具有相同超大质量黑洞（SMBHs）质量为10$^8$ M$_\odot$以及气体比例为30%和10%的星系合并上。 从模拟数据中，我们得出了活动星系核驱动的电离外流气体的速度和速度弥散图。 我们的研究结果表明，在星系合并的晚期阶段可以观测到速度弥散大于500 km s$^{-1}$ 的高速外流。 特别是，在被掩埋的活动星系核中，由于尘埃消光的明显效应，光度加权的外流速度和速度弥散都会增加。 由于这些效应，高气体比例模型的速度-速度弥散图显示出明显的蓝移倾斜。 关键的是，这种倾斜不受活动星系核光度的影响，而是源于尘埃消光的观测影响。 我们的结果暗示，在被掩埋的活动星系核中观测到的超过1000 km s$^{-1}$ 的高速\OIII 外流可能与气体丰富的星系合并晚期发生的尘埃消光有关。 显示英文摘要

摘要： In this study, we examine photoionization outflows during the late stages of galaxy mergers, with a specific focus on the relation between observed velocity of outflowing gas and the apparent effects of dust extinction. We used the N-body/smoothed particle hydrodynamics (SPH) code ASURA for galaxy merger simulations. These simulations concentrated on identical galaxy mergers featuring supermassive black holes (SMBHs) of 10$^8$ M$_\odot$ and gas fractions of 30\% and 10 \%. From the simulation data, we derived velocity and velocity dispersion diagrams for the AGN-driven ionized outflowing gas. Our findings show that high-velocity outflows with velocity dispersions of 500 km s$^{-1}$ or greater can be observed in the late stages of galactic mergers. Particularly, in buried AGNs, both the luminosity-weighted outflow velocity and velocity dispersion increase owing to the apparent effects of dust extinction. Owing to these effects, the velocity--velocity dispersion diagrams display a noticeable blue-shifted tilt in models with higher gas fractions. Crucially, this tilt is not influenced by the AGN luminosity but emerges from the observational impacts of dust extinction. Our results imply that the observed high-velocity \OIII outflow exceeding 1000 km s$^{-1}$ in buried AGNs may be linked to the dust extinction that occurs during the late stages of gas-rich galaxy mergers.