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arXiv 1602.04672astro-ph.GAastro-ph.CO
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黑洞质量估计:维里估计有多好?

Black Hole Mass Estimation: How good is the virial estimate?

Suk Yee Yong, Rachel L. Webster, Anthea L. King

摘要:

黑洞质量是决定黑洞如何与其环境相互作用的关键因素。然而,在高红移时黑洞质量的确定依赖于次级质量估计,而次级质量估计是基于经验关系和广泛的近似。建立了活动星系核(AGN)盘风宽线区(BLR)动力学模型,以检验不同BLR几何和活动星系核倾角对黑洞质量计算的影响.通过两个圆盘风模型的蒙特卡罗模拟,得到了不同倾角下的维里尺度因子$f$。所得到的$f$值与倾斜角密切相关,大的$f$值与小的倾斜角(接近正面)相关,小的$f$值与大的倾斜角(接近侧面)相关。$f$因子与先前根据经验关系确定的$f$值一致。将$f$设为常数可能会对大样本活动星系核的维里黑洞质量估计产生偏差。然而,偏置的程度取决于线宽特性(例如,半峰全宽(FWHM)或线色散)。使用$f_{\text{FWHM}}$估计的质量倾向于偏向较大的质量,但这可以通过校准发射线的宽度或形状来校正。

英文摘要:

Black hole mass is a key factor in determining how a black hole interacts with its environment. However, the determination of black hole masses at high redshifts depends on secondary mass estimators, which are based on empirical relationships and broad approximations. A dynamical disk wind broad line region (BLR) model of active galactic nuclei (AGN) is built in order to test the impact on the black hole mass calculation due to different BLR geometries and the inclination of the AGN. Monte Carlo simulations of two disk wind models are constructed to recover the virial scale factor, $f$, at various inclination angles. The resulting $f$ values strongly correlate with inclination angle, with large $f$ values associated with small inclination angles (close to face-on) and small $f$ values with large inclination angles (close to edge-on). The $f$ factors are consistent with previously determined $f$ values, found from empirical relationships. Setting $f$ as a constant may introduce a bias into virial black hole mass estimates for a large sample of AGN. However, the extent of the bias depends on the line width characterisation (e.g. full width at half maximum (FWHM) or line dispersion). Masses estimated using $f_{\text{FWHM}}$ tend to biased towards larger masses, but this can be corrected by calibrating for the width or shape of the emission line.

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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