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arXiv 2103.00138astro-ph.GAastro-ph.CO
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用光谱天体测量和混响映射测量类星体的几何距离:蒙特卡罗模拟

Geometric Distances of Quasars Measured by Spectroastrometry and Reverberation Mapping:Monte Carlo Simulations

Yu-Yang Songsheng, Yan-Rong Li, Pu Du, Jian-Min Wang

摘要:

最近,甚大望远镜干涉仪(VLTI)上的重力首次以前所未有的$\sim 10μ$分辨率空间解析了类星体3C 273的结构。通过对类星体宽线区(BLR)的光谱测量(SA)和混响成像(RM)观测的联合分析,成功地将一种新的视差距离测量方法应用于类星体。这种SA和RM(SARM)测量的不确定度约为实际数据的$16\%$,显示出其作为精密宇宙学的强大工具的巨大潜力。本文通过对模拟数据的详细分析,研究了SA观测数据质量对距离测量的影响,建立了距离的统计不确定度与差分相位相对误差之间的定量关系。我们采用一个圆盘模型的BLR的SARM分析。我们发现,SARM分析的意见一般产生可靠的类星体距离,即使是相对较差的SA测量误差棒的$40\%$在峰值的相位。超视距雷达的倾角和张开角是决定距离不确定性的主要参数。从SARM分析中发现,具有倾角$\gtrsim 10^{\circ}$和张开角$\lesssim 40^{\circ}$的BLR是距离测量的最可靠的区域。通过分析类星体光度函数产生的活动星系的模拟样本,我们发现,如果重力/重力+可以实现一个相位误差$0.1^{\circ}$每基线的目标与幅度$K \lesssim 11.5$,SARM活动可以约束$H_0$的不确定性$2\%$通过观察$60$目标。

英文摘要:

Recently, GRAVITY onboard the Very Large Telescope Interferometer (VLTI) first spatially resolved the structure of the quasar 3C 273 with an unprecedented resolution of $\sim 10μ$as. A new method of measuring parallax distances has been successfully applied to the quasar through joint analysis of spectroastrometry (SA) and reverberation mapping (RM) observation of its broad line region (BLR). The uncertainty of this SA and RM (SARM) measurement is about $16\%$ from real data, showing its great potential as a powerful tool for precision cosmology. In this paper, we carry out detailed analyses of mock data to study impacts of data qualities of SA observations on distance measurements and establish a quantitative relationship between statistical uncertainties of distances and relative errors of differential phases. We employ a circular disk model of BLR for the SARM analysis. We show that SARM analyses of observations generally generate reliable quasar distances, even for relatively poor SA measurements with error bars of $40\%$ at peaks of phases. Inclinations and opening angles of BLRs are the major parameters governing distance uncertainties. It is found that BLRs with inclinations $\gtrsim 10^{\circ}$ and opening angles $\lesssim 40^{\circ}$ are the most reliable regimes from SARM analysis for distance measurements. Through analysis of a mock sample of AGNs generated by quasar luminosity functions, we find that if the GRAVITY/GRAVITY+ can achieve a phase error of $0.1^{\circ}$ per baseline for targets with magnitudes $K \lesssim 11.5$, the SARM campaign can constrain $H_0$ to an uncertainty of $2\%$ by observing $60$ targets.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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