Star formation and dust attenuation properties in galaxies from a statistical ultraviolet‐to‐far‐infrared analysis
Star formation and dust attenuation properties in galaxies from a statistical ultraviolet‐to‐far‐infrared analysis
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DOI：
10.1111/j.1365-2966.2005.09131.x
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发表时间：
2005-04
影响因子：
4.8
通讯作者：
D. Burgarella;V. Buat;J. Marseille;France Instituto de Astrofisica de Andalucia-France-Instituto-de-Astrofisica-de-Andalucia-102578051;Spain.
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作者：
D. Burgarella;V. Buat;J. Marseille;France Instituto de Astrofisica de Andalucia-France-Instituto-de-Astrofisica-de-Andalucia-102578051;Spain.
我们研究了在近紫外 (NUV) 和远红外 (FIR) 中选择的两个星系样本，其中从远紫外 (FUV) 到 FIR 的光谱能量分布 (SED) 可用。我们将观测到的 SED 与具有多个恒星形成历史（SFH；衰变恒星形成率加爆发）和尘埃衰减定律（幂律 + 2175 A 碰撞）的模型 SED 进行了比较。贝叶斯方法允许人们通过将每个观察到的 SED 与全套 82 800 个模型进行比较来统计估计最佳参数。我们得出的结论是，如果不使用 FIR 信息，则无法通过 SED 分析正确估计 UV 灰尘衰减。色散比 FIR 数据大。该分布也不是关于零对称分布的：对 UV 选择的星系存在高估，对 FIR 选择的星系存在低估。分析过程的输出表明，UV 选择的星系的平均衰减规律类似于大麦哲伦云消光定律，而 FIR 选择的星系的衰减规律则更类似于银河系消光定律。对数 (Fdust /F FUV ) 与 FUV-NUV 图（一旦考虑了与 FUV - NUV 的主要关系）中的平均关系的离散性可以通过另外两个参数来解释：UV 选择星系的衰减定律的斜率和瞬时诞生率参数 b 0 以及 FIR 选择星系的相同参数加上凹凸强度。我们提出了一个方法来仅估计 UV 星系的 UV 尘埃衰减（仅当 FIR 信息不可用时才应使用，因为所得 A FUV 定义不明确，不确定性约为 0.32）： A FUV = 1.4168 (FUV - NUV) 2 + 0.3298 (NUV - I) 2 + 2.1207 (FUV - NUV) + 2.7465 (NUV) - I) + 5.8408。
We study two galaxies samples selected in near-ultraviolet (NUV) and in far-infrared (FIR) for which the spectral energy distributions (SEDs) from the far-UV (FUV) to the FIR are available. We compared the observed SEDs to modelled SEDs with several star formation histories (SFHs; decaying star formation rate plus burst) and dust attenuation laws (power law + 2175 A bump). The Bayesian method allows one to estimate statistically the best parameters by comparing each observed SED to the full set of 82 800 models. We reach the conclusion that the UV dust attenuation cannot be estimated correctly from SED analysis if the FIR information is not used. The dispersion is larger than with the FIR data. The distribution is also not symmetrically distributed about zero: there is an overestimation for UV-selected galaxies and an underestimation for FIR-selected galaxies. The output from the analysis process suggests that UV-selected galaxies have attenuation laws in average similar to the Large Magellanic Cloud extinction law while FIR-selected galaxies attenuation laws resemble more the Milky Way extinction law. The dispersion about the average relation in the log (F dust /F FUV ) versus FUV-NUV diagram (once the main relation with FUV - NUV accounted for) is explained by two other parameters: the slope of the attenuation law and the instantaneous birthrate parameters b 0 for UV-selected galaxies and the same ones plus the strength of the bump for the FIR-selected galaxies. We propose a recipe to estimate the UV dust attenuation for UV galaxies only (that should only be used whenever the FIR information is not available because the resulting A FUV is poorly defined with an uncertainty of about 0.32): A FUV = 1.4168 (FUV - NUV) 2 + 0.3298 (NUV - I) 2 + 2.1207 (FUV - NUV) + 2.7465 (NUV - I) + 5.8408.