Modelling the spectral energy distribution of galaxies. III. Attenuation of stellar light in spiral galaxies
Modelling the spectral energy distribution of galaxies. III. Attenuation of stellar light in spiral galaxies
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DOI：
10.1051/0004-6361:20035689
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发表时间：
2004-01
影响因子：
6.5
通讯作者：
R. Tuffs;C. Popescu;H. Voelk;N. Kylafis;M. A. D. Mpik;Heidelberg;U. Crete;Heraklion;F. F. Rese
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文献类型：
--
作者：
R. Tuffs;C. Popescu;H. Voelk;N. Kylafis;M. A. D. Mpik;Heidelberg;U. Crete;Heraklion;F. F. Rese
我们提出了新的计算的恒星光从螺旋星系使用几何形状的恒星和尘埃，可以再现整个光谱能量分布从紫外线（UV）到远红外（FIR）/亚毫米（submm），也可以占表面亮度分布在光学/近红外（NIR）和FIR/submm的衰减。这些计算是基于Popescu等人的模型，该模型包括一个无尘的恒星核球，一个由老恒星组成的星盘和相关的弥漫尘埃，一个由年轻恒星组成的薄星盘和相关的弥漫尘埃，以及一个与薄星盘中的恒星形成区域相关的星团尘埃成分。的衰减，其中包括多个各向异性散射的影响，分别为每个恒星组件，并在容易访问的多项式拟合的形式作为倾斜度的函数，在光学深度和波长的网格。所考虑的波长范围是在912 A和2.2 ${\mu}$m之间，采样使得可以方便地计算标准光学波段和GALEX覆盖的波段的衰减。各个恒星成分的衰减特性表现出明显的差异。给出了一个计算复合衰减的通用公式，适用于任何组合的凸起到磁盘的比率和团块量。作为一个例子，我们展示了如何从衰减随倾角的变化得出的光学深度取决于隆起盘比。最后，给出了一个配方的自洽确定的光学深度从${\rmH\alpha}/{\rmH\beta}$线比。
We present new calculations of the attenuation of stellar light from spiral galaxies using geometries for stars and dust which can reproduce the entire spectral energy distribution from the ultraviolet (UV) to the Far-infrared (FIR)/submillimeter (submm) and can also account for the surface brightness distribution in both the optical/Near-infrared (NIR) and FIR/submm. The calculations are based on the model of Popescu et al. ([CITE]), which incorporates a dustless stellar bulge, a disk of old stars with associated diffuse dust, a thin disk of young stars with associated diffuse dust, and a clumpy dust component associated with star-forming regions in the thin disk. The attenuations, which incorporate the effects of multiple anisotropic scattering, are derived separately for each stellar component, and presented in the form of easily accessible polynomial fits as a function of inclination, for a grid in optical depth and wavelength. The wavelength range considered is between 912 A and 2.2 ${\mu}$m, sampled such that attenuation can be conveniently calculated both for the standard optical bands and for the bands covered by GALEX. The attenuation characteristics of the individual stellar components show marked differences between each other. A general formula is given for the calculation of composite attenuation, valid for any combination of the bulge-to-disk ratio and amount of clumpiness. As an example, we show how the optical depth derived from the variation of attenuation with inclination depends on the bulge-to-disk ratio. Finally, a recipe is given for a self-consistent determination of the optical depth from the ${\rm H\alpha}/{\rm H\beta}$ line ratio.