期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 465, 期 4, 页码 4348-4362出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/stw2955
关键词
dust, extinction; ISM: general; galaxies: active; galaxies: general; galaxies: ISM; X-rays: ISM
资金
- CONICYT-Chile [PFB-06/2007, 1141218, 3160439, ACT1101]
- Ministry of Economy, Development, and Tourism's Millennium Science Initiative [IC120009]
The 'torus' obscurer of active galactic nuclei (AGN) is poorly understood in terms of its density, sub-structure and physical mechanisms. Large X-ray surveys provide model boundary constraints, for both Compton-thin and Compton-thick levels of obscuration, as obscured fractions aremean covering factors integral(cov). However, a major remaining uncertainty is host-galaxy obscuration. In Paper I, we discovered a relation of N-H proportional to M-star(1/3) for the obscuration of galaxyscale gas. Here, we apply this observational relation to the AGN population, and find that galaxy-scale gas is responsible for a luminosity-independent fraction of Compton-thin AGN, but does not produce Compton-thick columns. With the host-galaxy obscuration understood, we present a model of the remaining nuclear obscurer, which is consistent with a range of observations. Our radiation-lifted torus model consists of a Compton-thick component (integral(cov) similar to 35 per cent) and a Compton-thin component (integral(cov) similar to 40 per cent), which depends on both black hole mass and luminosity. This provides a useful summary of observational constraints for torus modellers who attempt to reproduce this behaviour. It can also be employed as a sub-grid recipe in cosmological simulations that do not resolve the torus. We also investigate host-galaxy X-ray obscuration inside cosmological, hydrodynamic simulations (Evolution and Assembly of Galaxies and their Environment; Illustris). The obscuration from ray-traced galaxy gas can agree with observations, but is highly sensitive to the chosen feedback assumptions.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据