INVESTIGATING THE PRESENCE OF 500 μm SUBMILLIMETER EXCESS EMISSION IN LOCAL STAR FORMING GALAXIES
INVESTIGATING THE PRESENCE OF 500 μm SUBMILLIMETER EXCESS EMISSION IN LOCAL STAR FORMING GALAXIES
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DOI：
10.1088/0004-637x/778/1/51
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发表时间：
2013-10
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通讯作者：
A. Kirkpatrick;D. Calzetti;M. Galametz;Robert C. Kennicutt Jr.;D. Dale;G. Aniano;K. Sandstrom;L. Armus;A. Crocker;J. Hinz;L. Hunt;J. Koda;F. Walter
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作者：
A. Kirkpatrick;D. Calzetti;M. Galametz;Robert C. Kennicutt Jr.;D. Dale;G. Aniano;K. Sandstrom;L. Armus;A. Crocker;J. Hinz;L. Hunt;J. Koda;F. Walter
据报道，在少数几个本地星系中，在500 μm处有亚毫米的过量发射，以前的研究表明，它可能与金属丰度有关。我们调查了来自邻近星系的关键洞察的20个星系样本在500 μm处的过量亚毫米波发射的存在：Herschel的远红外巡天（KINGFISH），这些星系跨越了一系列形态和金属丰度（12 + log（O/H）= 7.8-8.7）。我们使用斯皮策太空望远镜和赫歇尔空间天文台在24-500 μm波长范围内的图像探测远红外（IR）发射。我们用双温修正黑体模拟尘埃辐射的远红外峰，并测量了相对于我们模型预测的500 μm测光的超额。我们比较了亚毫米过量，目前，与全球星系金属丰度，并在可用的情况下，解决金属丰度测量。我们没有发现500 μm过量与金属丰度之间的任何相关性。少数个别源在500 μm处确实显示出过量（10%-20%）;相反，对于其他源，模型将测量到的500 μm通量密度高估了20%，造成500 μm的“不足”。我们的源都没有超过计算的1σ不确定度的过量，这使我们得出结论，在我们的样品中，在500 μm或更短的亚毫米波长处没有实质性的过量。我们的结果不同于以前的研究检测500 μm的过量在KINGFISH星系主要是由于新的，改进的光度学在这项研究中使用。
Submillimeter excess emission has been reported at 500 μm in a handful of local galaxies, and previous studies suggest that it could be correlated with metal abundance. We investigate the presence of an excess submillimeter emission at 500 μm for a sample of 20 galaxies from the Key Insights on Nearby Galaxies: a Far Infrared Survey with Herschel (KINGFISH) that span a range of morphologies and metallicities (12 + log (O/H) = 7.8–8.7). We probe the far-infrared (IR) emission using images from the Spitzer Space Telescope and Herschel Space Observatory in the wavelength range 24–500 μm. We model the far-IR peak of the dust emission with a two-temperature modified blackbody and measure excess of the 500 μm photometry relative to that predicted by our model. We compare the submillimeter excess, where present, with global galaxy metallicity and, where available, resolved metallicity measurements. We do not find any correlation between the 500 μm excess and metallicity. A few individual sources do show excess (10%–20%) at 500 μm; conversely, for other sources, the model overpredicts the measured 500 μm flux density by as much as 20%, creating a 500 μm “deficit.” None of our sources has an excess larger than the calculated 1σ uncertainty, leading us to conclude that there is no substantial excess at submillimeter wavelengths at or shorter than 500 μm in our sample. Our results differ from previous studies detecting 500 μm excess in KINGFISH galaxies largely due to new, improved photometry used in this study.