The distribution of the ISM in the Milky Way - A three-dimensional large-scale model
The distribution of the ISM in the Milky Way - A three-dimensional large-scale model
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DOI：
10.1051/0004-6361:20054618
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发表时间：
2006-07
影响因子：
6.5
通讯作者：
A. Misiriotis;E. Xilouris;J. Papamastorakis;P. Boumis;C. Goudis
中科院分区：
文献类型：
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作者：
A. Misiriotis;E. Xilouris;J. Papamastorakis;P. Boumis;C. Goudis
我们使用COBE/DIRBE（1.2、2.2、60、100、140和240 μm）图和COBE/FIRAS光谱（波长范围为100 - 1000 μm）来约束银河系中尘埃、恒星和气体的空间分布模型。通过假设尘埃和恒星的指数轴对称分布，并通过执行相应的辐射传输计算，我们密切（给定简单的几何模型）重现银河系的FIR和NIR地图。使用圆盘中氢原子和氢分子的类似分布（氢原子具有内部截止半径）来拟合气体数据。星星的形成率作为银河系半径的函数是来自FIR发射，并与现有的各种星星形成示踪剂的估计是一致的。将气体表面密度与星星形成率密度绘制成图，并推导出“本征”银河系施密特定律，该定律与螺旋星系中发现的“外部”施密特定律非常一致。银河系的外层和内层分别消耗了0.1%和0.10%的气体（周期为0.1 Gyr）来制造恒星。尘埃引起的B − V色过剩观察到在不同方向和距离（高达6.5千秒差距）与充分研究造父变星的模型预测相比，显示出良好的协议。银河系中恒星和尘埃指数分布的简单假设被认为是非常有指导意义的，并且足以模拟从0.45 µ m（B波段）到1000 µm的所有可用数据集。
We use the COBE/DIRBE (1.2, 2.2, 60, 100, 140, and 240 µm) maps and the COBE/FIRAS spectra (for the wavelength range 100−1000 µm) to constrain a model for the spatial distribution of the dust, the stars, and the gas in the Milky Way. By assuming exponential axisymmetric distributions for the dust and the stars and by performing the corresponding radiative transfer calculations we closely (given the simple geometry of the model) reproduce the FIR and NIR maps of the Milky Way. Similar distributions for the atomic and molecular hydrogen in the disk are used (with an inner cut-off radius for the atomic hydrogen) to fit the gas data. The star formation rate as a function of the Galactic radius is derived from the FIR emission and is well in agreement with existing estimates from various star formation tracers. The gas surface density is plotted against the star formation rate density and an “intrinsic” Galactic Schmidt law is derived with excellent agreement with the “external” Schmidt law found for spiral galaxies. The Milky Way is found to consume ∼1% and ∼10% of its gas in the outer and inner regions respectively (for a period of 0.1 Gyr) to make stars. The dust-induced B − V color excess observed in various directions and distances (up to ∼6.5 kpc) with well-studied Cepheid stars is compared with the model predictions showing a good agreement. The simple assumption of exponential distributions of stars and dust in the Galaxy is found to be quite instructive and adequate in modeling all the available data sets from 0.45 µ m( B-band) to 1000 µm.