WHAT SHAPES THE FAR-INFRARED SPECTRAL ENERGY DISTRIBUTIONS OF GALAXIES?
WHAT SHAPES THE FAR-INFRARED SPECTRAL ENERGY DISTRIBUTIONS OF GALAXIES?
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星系的远红外光谱能量分布是怎样形成的？
DOI：
10.3847/0004-637x/818/1/62
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
R. Somerville
中科院分区：
文献类型：
--
作者：
M. Safarzadeh;C. Hayward;H. Ferguson;R. Somerville
为了探索星系的整体物理特性与其远红外 (FIR) 光谱能量分布 (SED) 之间的联系，我们研究了一组 51 个流体动力学模拟星系的 FIR SED 的变化，这些星系包括代表低红移和高红移星系的合并系统和孤立系统，这些星系是通过在后处理中执行尘埃辐射传输而生成的。我们使用主成分 (PC) 分析研究 FIR SED，发现样本中 97% 的方差可以用两个 PC 来解释。第一个 PC 表征 FIR SED 峰值的波长，第二个 PC 编码 SED 的宽度。我们发现，使用红外光度和尘埃质量的双幂律可以很好地预测两个 PC 的系数，这表明这两个物理特性是星系 FIR SED 形状的主要决定因素。纳入星系大小并不能显着提高我们预测 FIR SED 的能力。我们的结果表明，在固定红外光度下观察到的有效尘埃温度的红移演化并不是由几何驱动的：z ∼ 2 − 3 ?> 超光度红外星系（ULIRG）的SED比本地ULIRG的温度低，不是因为高红移星系更延伸，而是因为它们在固定红外光度下具有更高的尘埃质量。最后，根据我们的模拟，我们引入了一组取决于红外光度和灰尘质量的双参数 SED 模板。
To explore the connection between the global physical properties of galaxies and their far-infrared (FIR) spectral energy distributions (SEDs), we study the variation in the FIR SEDs of a set of 51 hydrodynamically simulated galaxies, both mergers and isolated systems representative of low- and high-redshift galaxies, that are generated by performing dust radiative transfer in post-processing. We study the FIR SEDs using principal component (PC) analysis, and find that 97% of the variance in the sample can be explained by two PCs. The first PC characterizes the wavelength of the peak of the FIR SED, and the second encodes the breadth of the SED. We find that the coefficients of both PCs can be predicted well using a double power law in terms of the IR luminosity and dust mass, which suggests that these two physical properties are the primary determinants of galaxies’ FIR SED shapes. Incorporating galaxy sizes does not significantly improve our ability to predict the FIR SEDs. Our results suggest that the observed redshift evolution in the effective dust temperature at a fixed IR luminosity is not driven by geometry: the SEDs of z ∼ 2 − 3 ?> ultraluminous IR galaxies (ULIRGs) are cooler than those of local ULIRGs, not because the high-redshift galaxies are more extended, but rather because they have higher dust masses at fixed IR luminosity. Finally, based on our simulations, we introduce a two-parameter set of SED templates that depend on both IR luminosity and dust mass.
赫歇尔-阿特拉斯巡天中两个边缘螺旋星系的尘埃能量平衡研究
影响因子：
4.8
作者：
De Geyter G
通讯作者：
De Geyter G