Large and small-scale structures and the dust energy balance problem in spiral galaxies
Large and small-scale structures and the dust energy balance problem in spiral galaxies
复制标题
螺旋星系大小尺度结构与尘埃能量平衡问题
DOI：
--
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
I. D. Looze
中科院分区：
文献类型：
--
作者：
W. Saftly;M. Baes;G. D. Geyter;P. Camps;F. Renaud;J. Guedes;I. D. Looze;I. D. Looze
星系中的星际尘埃含量可以通过光学波长的消光或远红外线的发射来追踪。一些研究发现，成功解释边缘螺旋星系消光的辐射传输模型通常低估了观测到的FIR/submm通量约三倍。为了研究这个所谓的尘埃能量平衡问题，我们使用了两个高分辨率流体动力学模拟产生的银河系类星系。我们创建这些模拟星系的模拟光学边缘视图（使用辐射传输代码SKIRT），然后我们将基本螺旋星系模型的参数拟合到这些图像（使用拟合代码FitSKIRT）。基本模型包括光滑的轴对称分布沿着一个S\'ersic隆起和指数盘的恒星，和第二个指数盘的尘埃。我们发现，恢复的尘埃质量的拟合模型是约三倍小于已知的尘埃质量的流体动力学输入模型。这个因子与以前对真实的边缘螺旋星系的能量平衡研究是一致的。另一方面，将相同的基本模型拟合到不太复杂的输入模型（例如，具有螺旋扰动或随机团块的平滑指数盘），确实几乎完美地恢复了输入模型的尘埃质量。这样看来，真实的和流体动力学模拟的星系的复杂的不对称性和不均匀的结构在隐藏尘埃方面比典型的准解析模型中人为设计的几何形状要有效得多。这种效应可能有助于解释辐射传输模型预测的尘埃排放与边缘旋涡星系能量平衡研究中观测到的排放之间的差异。
The interstellar dust content in galaxies can be traced in extinction at optical wavelengths, or in emission in the far-infrared. Several studies have found that radiative transfer models that successfully explain the optical extinction in edge-on spiral galaxies generally underestimate the observed FIR/submm fluxes by a factor of about three. In order to investigate this so-called dust energy balance problem, we use two Milky Way-like galaxies produced by high-resolution hydrodynamical simulations. We create mock optical edge-on views of these simulated galaxies (using the radiative transfer code SKIRT), and we then fit the parameters of a basic spiral galaxy model to these images (using the fitting code FitSKIRT). The basic model includes smooth axisymmetric distributions along a S\'ersic bulge and exponential disc for the stars, and a second exponential disc for the dust. We find that the dust mass recovered by the fitted models is about three times smaller than the known dust mass of the hydrodynamical input models. This factor is in agreement with previous energy balance studies of real edge-on spiral galaxies. On the other hand, fitting the same basic model to less complex input models (e.g. a smooth exponential disc with a spiral perturbation or with random clumps), does recover the dust mass of the input model almost perfectly. Thus it seems that the complex asymmetries and the inhomogeneous structure of real and hydrodynamically simulated galaxies are a lot more efficient at hiding dust than the rather contrived geometries in typical quasi-analytical models. This effect may help explain the discrepancy between the dust emission predicted by radiative transfer models and the observed emission in energy balance studies for edge-on spiral galaxies.
M33 的 PACS 和 SPIRE 光度计图：Herschel M33 扩展勘测 (HERM33ES) 的第一个结果
影响因子：
6.5
作者：
Kramer
通讯作者：
Kramer
盘状星系中的辐射传输 - IV 尘埃衰减对核球和盘状结构参数的影响
DOI：
10.1111/j.1365-2966.2010.16243.x
发表时间：
2010
影响因子：
4.8
作者：
Gadotti;Falony
通讯作者：
Falony