arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0810.1950astro-ph
收藏

用MgII估算活动星系核中黑洞质量的一种改进方法

An Improved Method for Using MgII to Estimate Black Hole Masses in Active Galactic Nuclei

Christopher A. Onken, Juna A. Kollmeier

备注：
10 pages including 4 figures, submitted to ApJL, incorporates referee's comments
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

提出了一种从活动星系核（AGN）中的Mg Ⅱ发射线获得精确的黑洞（BH）质量估计的方法。利用Shen等人提出的Sloan数字巡天（SDSS）的大型活动星系核测量数据库，我们发现，在红移范围0.3-0.9的活动星系核，对于一个给定的对象可以有H-β和MgII线宽测量，显示一个适度的，但可纠正的差异，在MgII为基础的质量与爱丁顿比。我们使用SDSS数据库来估计真实（即，基于H-β）质量。然后将这些概率分布应用于Shen等人在整个MgII可接近的红移范围（0.3-2.2）内的SDSS测量。我们发现，这种剩余相关性的会计一般增加了一个小的因素（约0.09德克斯的红移和光度箱，我们认为）的爱丁顿比的色散。我们继续发现，发光活动星系核的爱丁顿比的内在分布是非常窄的，0.3-0.4德克斯，证明由Kollmeier等人。使用我们描述的方法，镁II发射线可以使用的信心，以获得BH质量估计。

英文摘要：

We present a method for obtaining accurate black hole (BH) mass estimates from the MgII emission line in active galactic nuclei (AGNs). Employing the large database of AGN measurements from the Sloan Digital Sky Survey (SDSS) presented by Shen et al., we find that AGNs in the redshift range 0.3-0.9, for which a given object can have both H-beta and MgII line widths measured, display a modest but correctable discrepancy in MgII-based masses that correlates with the Eddington ratio. We use the SDSS database to estimate the probability distribution of the true (i.e., H-beta-based) mass given a measured MgII line width. These probability distributions are then applied to the SDSS measurements from Shen et al. across the entire MgII-accessible redshift range (0.3-2.2). We find that accounting for this residual correlation generally increases the dispersion of Eddington ratios by a small factor (~0.09 dex for the redshift and luminosity bins we consider). We continue to find that the intrinsic distribution of Eddington ratios for luminous AGNs is extremely narrow, 0.3-0.4 dex, as demonstrated by Kollmeier et al. Using the method we describe, MgII emission lines can be used with confidence to obtain BH mass estimates.

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。

↑