论文标题
关于尘埃和恒星种群的同时建模,用于解释星系特性
On the Simultaneous Modelling of Dust and Stellar Populations for Interpretation of Galaxy Properties
论文作者
论文摘要
星系的物理特性在其光谱能量分布中编码,并需要与要提取的模型进行比较。这些模型必须包含合成的恒星种群,并且要使用红外数据,还考虑了通过灰尘重新处理和重新排放能量的处方。尽管已经构建了许多这样的模型,但几乎没有关于恒星种群模型选择对衍生尘埃参数的影响的分析,反之亦然。在这里,我们应用一个简单的框架来比较这些选择的影响,结合了三个常用的恒星种群合成模型和三个灰尘发射模型。我们将拟合与紫外线的紫外线能量分布进行比较。我们发现,在恒星合成模型中,包括不同的物理学,例如二进制恒星的演化,可以在灰尘和恒星发射模型的派生参数中引入偏见和不确定性,这在很大程度上是由于可用于重新处理的远导发射发射的差异。这可能有助于调和宇宙恒星形成率与恒星质量密度历史之间的差异。值得注意的是,在灰尘发射模型中包含尘土飞扬的出生云成分为适应恒星种群模型提供了更大的灵活性,因为其重新排放对紫外线辐射场光谱和密度非常敏感。二元种群比仅假设单一恒星种群合成时发现的比出生云耗散时间尺度更长。
The physical properties of galaxies are encoded within their spectral energy distribution and require comparison with models to be extracted. These models must contain a synthetic stellar population and, where infrared data is to be used, also consider prescriptions for energy reprocessing and re-emission by dust. While many such models have been constructed, there are few analyses of the impact of stellar population model choice on derived dust parameters, or vice versa. Here we apply a simple framework to compare the impact of these choices, combining three commonly-used stellar population synthesis models and three dust emission models. We compare fits to the ultraviolet to far-infrared spectral energy distributions of a validation sample of infrared-luminous galaxies. We find that including different physics, such as binary stellar evolution, in the stellar synthesis model can introduce biases and uncertainties in the derived parameters of the dust and stellar emission models, largely due to differences in the far-ultraviolet emission available for reprocessing. This may help to reconcile the discrepancy between the cosmic star formation rate and stellar mass density histories. Notably the inclusion of a dusty stellar birth cloud component in the dust emission model provides more flexibility in accommodating the stellar population model, as its reemission is highly sensitive to the ultraviolet radiation field spectrum and density. Binary populations favour a longer birth cloud dissipation timescale than is found when assuming only single star population synthesis.