Galactic winds and extended Lya emission from the host galaxies of high column density quasi-stellar object absorption systems Galactic winds and extended Lya emission
Galactic winds and extended Lya emission from the host galaxies of high column density quasi-stellar object absorption systems Galactic winds and extended Lya emission
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高柱密度准星体吸收系统主星系的银河风和扩展 Lya 发射 银河风和扩展 Lya 发射
DOI：
10.1111/j.1365-2966.2011.18789.x
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发表时间：
2011
影响因子：
4.8
通讯作者：
Barnes L
中科院分区：
文献类型：
--
作者：
Barnes L
我们提出了高柱密度吸收系统atz ~ 3宿主星系中中心源Lyα辐射的空间和光谱扩散的三维（3D）共振辐射传输模拟。辐射传输模拟是基于一套宇宙星系形成模拟，这些模拟再现了阻尼Lyα吸收系统的广泛观测特性。预计Lyα发射在空间上扩展到几个弧秒，并且Lyα发射的光谱宽度被拓宽到几百（在某些情况下超过几千）km s−1。模拟星系中气体的分布和动力学状态是复杂的，后者主要来自旋转和流入和流出。出现的Lyα辐射延伸到柱密度为nh I ~ 1018cm−2的气体中，其光谱形状随观测角度的变化很大。对中心hicolem密度和Hivelocity场的强烈依赖表明，在中心区域的几个动力学时间尺度上，Lyα发射也会随时间发生强烈的变化。这种随时间的变化在宿主星系经历一次大合并和/或星暴的时候应该特别明显。根据沿给定视线的流入或流出的优势和中心柱密度，光谱显示出明显的蓝峰、红峰或双峰轮廓。空间分布和光谱形状对星系风实现的细节非常敏感。更强的星系风导致Lyα在空间上的发射范围更广，光谱分布也更窄。
We present three-dimensional (3D) resonant radiative transfer simulations of the spatial and spectral diffusion of the Lyα radiation from a central source in the host galaxies of high column density absorption systems atz∼ 3. The radiative transfer simulations are based on a suite of cosmological galaxy formation simulations which reproduce a wide range of observed properties of damped Lyα absorption systems. The Lyα emission is predicted to be spatially extended up to several arcsec, and the spectral width of the Lyα emission is broadened to several hundred (in some case more than thousand) km s−1. The distribution and the dynamical state of the gas in the simulated galaxies are complex, the latter with significant contributions from rotation and both in- and out-flows. The emerging Lyα radiation extends to gas with column densities ofNH I∼ 1018cm−2and its spectral shape varies strongly with viewing angle. The strong dependence on the central Hicolumn density and the Hivelocity field suggests that the Lyα emission will also vary strongly with time on time-scales of a few dynamical times of the central region. Such variations with time should be especially pronounced at times where the host galaxy undergoes a major merger and/or starburst. Depending on the pre-dominance of in- or out-flow along a given sightline and the central column density, the spectra show prominent blue peaks, red peaks or double-peaked profiles. Both spatial distribution and spectral shape are very sensitive to details of the galactic wind implementation. Stronger galactic winds result in more spatially extended Lyα emission and – somewhat counterintuitively – a narrower spectral distribution.