The Herschel exploitation of local galaxy Andromeda (HELGA) V: Strengthening the case for substantial interstellar grain growth
The Herschel exploitation of local galaxy Andromeda (HELGA) V: Strengthening the case for substantial interstellar grain growth
复制标题
赫歇尔对当地星系仙女座 (HELGA) V 的探索：强化了星际颗粒大量生长的理由
DOI：
10.1093/mnras/stu1228
复制
发表时间：
2014
影响因子：
4.8
通讯作者：
L. Spinoglio
中科院分区：
文献类型：
--
作者：
Lars Mattsson;Lars Mattsson;H. Gomez;Anja C. Andersen;Matthew W. L. Smith;I. D. Looze;M. Baes;S. Viaene;Gianfranco Gentile;Gianfranco Gentile;J. Fritz;L. Spinoglio
在本文中，我们考虑的尘埃和金属的分布在M31盘的含义。我们得出平均径向尘埃分布使用的尘埃地图从赫歇尔图像的M31采样整个远红外峰。修改后的黑体适合约4000像素的变化，以及一个固定的，灰尘发射率指数（β）。还使用从文献中收集的数据推导出总体金属分布。我们使用一个简单的分析模型的尘埃在一个星系中的恒星源和星际颗粒生长贡献的尘埃的演变，并适合这个模型的径向尘埃到金属分布在整个星系。我们的分析表明，M31中的尘埃-气体梯度比金属丰度梯度更陡，这表明星际尘埃的增长在M31中是（或曾经是）重要的。我们认为，M31有助于建立一个宇宙尘埃的情况下，星系是大量的星际颗粒生长的结果，而从恒星的净尘埃生产可能是有限的。然而，我们注意到，在我们的简单模型中，恒星中尘埃产生的效率，例如在超新星喷出物和/或恒星大气中，以及星际介质中的颗粒破坏可能是退化的。我们可以得出这样的结论：在M31中，由吸积作用导致的星际颗粒生长可能至少与恒星尘埃产生通道一样重要。
In this paper, we consider the implications of the distributions of dust and metals in the disc of M31. We derive mean radial dust distributions using a dust map created from Herschel images of M31 sampling the entire far-infrared peak. Modified blackbodies are fit to approximately 4000 pixels with a varying, as well as a fixed, dust emissivity index (beta). An overall metal distribution is also derived using data collected from the literature. We use a simple analytical model of the evolution of the dust in a galaxy with dust contributed by stellar sources and interstellar grain growth, and fit this model to the radial dust-to-metals distribution across the galaxy. Our analysis shows that the dust-to-gas gradient in M31 is steeper than the metallicity gradient, suggesting interstellar dust growth is (or has been) important in M31. We argue that M31 helps build a case for cosmic dust in galaxies being the result of substantial interstellar grain growth, while the net dust production from stars may be limited. We note, however, that the efficiency of dust production in stars, e.g. in supernovae ejecta and/or stellar atmospheres, and grain destruction in the interstellar medium may be degenerate in our simple model. We can conclude that interstellar grain growth by accretion is likely at least as important as stellar dust production channels in building the cosmic dust component in M31.