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arXiv 1404.3151astro-ph.GA
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类星体内禀光度函数:考虑吸积盘各向异性

The Intrinsic Quasar Luminosity Function: Accounting for Accretion Disk Anisotropy

M. A. DiPompeo, A. D. Myers, M. S. Brotherton, J. C. Runnoe, R. F. Green

摘要:

类星体光度函数是研究超大质量黑洞生长和演化的基本工具。测量内禀光度函数在实践中是困难的,由于大量的观测和系统的影响。随着样本量的增加和测量误差的下降,表征系统效应变得更加重要。众所周知,类星体的吸积盘的连续辐射是各向异性的-部分原因是它的盘状结构-但目前的光度函数计算有效地假设了在未遮蔽视线范围内的各向同性。在这里,我们提供的第一步,在随机类星体的取向和简单的模型上观察到的光度函数的各向异性的影响进行表征。我们发现,方向的影响是不是微不足道的,并超过其他潜在的修正,如那些从引力透镜的前景结构。我们认为,目前的观测约束可能高估了内禀光度函数多达一个因素~2的亮端。这对类星体的模型及其在宇宙中的作用有影响,例如类星体对宇宙学背景的贡献。

英文摘要:

Quasar luminosity functions are a fundamental probe of the growth and evolution of supermassive black holes. Measuring the intrinsic luminosity function is difficult in practice, due to a multitude of observational and systematic effects. As sample sizes increase and measurement errors drop, characterizing the systematic effects is becoming more important. It is well known that the continuum emission from the accretion disk of quasars is anisotropic --- in part due to its disk-like structure --- but current luminosity function calculations effectively assume isotropy over the range of unobscured lines of sight. Here, we provide the first steps in characterizing the effect of random quasar orientations and simple models of anisotropy on observed luminosity functions. We find that the effect of orientation is not insignificant and exceeds other potential corrections such as those from gravitational lensing of foreground structures. We argue that current observational constraints may overestimate the intrinsic luminosity function by as much as a factor of ~2 on the bright end. This has implications for models of quasars and their role in the Universe, such as quasars' contribution to cosmological backgrounds.

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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