A robust method for investigating galactic evolution in the submillimetre waveband — II. The submillimetre background and source counts
A robust method for investigating galactic evolution in the submillimetre waveband — II. The submillimetre background and source counts
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一种研究亚毫米波段星系演化的可靠方法——亚毫米背景和源计数。
DOI：
10.1093/mnras/286.3.732
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
M. Edmunds
中科院分区：
文献类型：
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作者：
S. Eales;M. Edmunds
这是两篇论文中的第二篇，描述了亚毫米波段的星系演化模型。该模型采用了自洽处理的尘埃和恒星的演化，是正规化的亚毫米性质的星系在当地的宇宙，并可用于作出预测盘和椭圆星系和“封闭盒”，“流入”，和“流出”模型的星系演化。该模型不包括层次聚类的影响，但我们表明，不同的灰尘演变模型产生的预测的变化是如此之大，它是不成熟的，包括一个更不确定的过程的影响。在论文I中，我们研究了是否有可能用星系演化来解释高红移类星体和射电星系的极高尘埃质量。在本文中，我们使用该模型进行预测的亚毫米背景和源计数。
我们所有的盘星系模型在短波长（λ < 200 μm）下都超过了Puget等人（1996）最近测量的亚毫米背景，这表明我们的模型有问题，或者在短波长下的背景测量不准确，或者两者兼而有之。然而，这两个模型中，我们假设快速演变的星星形成率发现从光学研究预测的背景是如此之大，比测量的背景，我们不相信这种差异可以是一个不准确的背景测量的结果。因此，我们的结论是，没有证据表明，在亚毫米波段的光学研究中发现的快速演变。在较长的波长下，大多数盘星系模型预测的背景都小于观测到的背景。我们的椭圆星系模型更不确定，因为它们与观测到的局部宇宙的亚毫米性质联系得不那么牢固。我们发现，这是相对容易产生的模型，预测类似的背景下观察到的，但我们警告说，我们的盘星系模型显示，观察到的背景的一个显着的一部分必须来自盘星系。在我们的模型中的主要弱点是缺乏一个直接测量的亚毫米光度函数的星系和事实上，我们一直被迫假设，所有本地盘星系有相同的远红外亚毫米光谱能量分布和相同的气体质量比恒星质量。用水下呼吸器亚毫米阵列进行观测，应该可以消除这两个弱点，并提供测量的源计数，以便与模型对抗。
This is the second of two papers describing a model of galactic evolution in the submillimetre waveband. The model incorporates a self-consistent treatment of the evolution of dust and stars, is normalized to the submillimetre properties of galaxies in the local Universe, and can be used to make predictions for both disc and elliptical galaxies and for ‘closed-box’, ‘inflow’, and ‘outflow’ models of galactic evolution. The model does not include the effects of hierarchical clustering, but we show that the variation in the predictions produced by the different dust-evolution models is so large that it is premature to include the effects of an even more uncertain process. In Paper I we investigated whether it is possible to explain the extremely high dust masses of high-redshift quasars and radio galaxies by galactic evolution. In this paper we use the model to make predictions about the submillimetre background and source counts.
All our disc galaxy models exceed at short wavelengths (λ < 200 μm) the submillimetre background recently measured by Puget et al. (1996), suggesting either that there is a problem with our models, or that the background measurement at the shorter wavelengths is inaccurate, or a combination of the two. However, the two models in which we assume the rapidly evolving star formation rate found from optical studies predict backgrounds that are so much greater than the measured background that we do not believe that this discrepancy can be the result of an inaccurate background measurement. We therefore conclude that there is no evidence in the submillimetre waveband for the rapid evolution found from optical studies. At longer wavelengths, most of the disc galaxy models predict backgrounds that are less than the observed background. Our elliptical galaxy models are more uncertain because they are less securely tied to the observed submillimetre properties of the local Universe. We find that it is relatively easy to produce models that predict backgrounds similar to that observed, but we caution that our disc galaxy models show that a significant fraction of the observed background must be coming from disc galaxies. The main weaknesses in our models are the lack of a direct measurement of the submillimetre luminosity function for galaxies and the fact that we have been forced to assume that all local disc galaxies have the same farinfrared-submillimetre spectral energy distribution and the same ratio of gas mass to stellar mass. Observations with the SCUBA submillimetre array should remove both of these weaknesses, as well as providing measured source counts with which to confront the models.