arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1209.3773astro-ph.CO
收藏

局部活动星系维里因子和M-σ关系的重新标定

Recalibration of the virial factor and M-sigma relation for local active galaxies

Daeseong Park, Brandon C. Kelly, Jong-Hak Woo, Tommaso Treu

摘要:

确定宽线区(BLR)气体的维里因子是校准活动星系核黑洞质量估计的关键,因为测量的视线速度需要转换为内禀维里速度。平均维里因子已经根据静止星系的M-西格玛关系进行了经验校准,但在最近的研究中,所声称的值相差两个因子。我们调查的差异的起源,通过测量的M-西格玛关系,使用更新的星系样本从文献中,并探讨各种拟合方法的维里因子的依赖。我们发现,这种差异主要是由样本选择造成的,而各种回归方法的差异是微不足道的。然而,我们通常更喜欢基于蒙特卡罗模拟的M-sigma关系的FITEXY和贝叶斯估计。此外,回归中自变量的选择导致从校准过程推断的维里因子的~0.2 dex变化。在确定维里因子的基础上,给出了更新的局域活动星系的M-σ关系。

英文摘要:

Determining the virial factor of the broad-line region (BLR) gas is crucial for calibrating AGN black hole mass estimators, since the measured line-of-sight velocity needs to be converted into the intrinsic virial velocity. The average virial factor has been empirically calibrated based on the M-sigma relation of quiescent galaxies, but the claimed values differ by a factor of two in recent studies. We investigate the origin of the difference by measuring the M-sigma relation using an updated galaxy sample from the literature, and explore the dependence of the virial factor on various fitting methods. We find that the discrepancy is primarily caused by the sample selection, while the difference stemming from the various regression methods is marginal. However, we generally prefer the FITEXY and Bayesian estimators based on Monte Carlo simulations for the M-sigma relation. In addition, the choice of independent variable in the regression leads to ~0.2 dex variation in the virial factor inferred from the calibration process. Based on the determined virial factor, we present the updated M-sigma relation of local active galaxies.

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。

↑