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arXiv 2205.07591astro-ph.GA
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一个与尘埃演化相一致的新的星系光谱能量分布模型

A new galaxy spectral energy distribution model consistent with the evolution of dust

Kazuki Y. Nishida, Tsutomu T. Takeuchi, Takuma Nagata, Ryosuke S. Asano

摘要:

星系的光谱能量分布(SED)提供了有关物理过程的基本信息。然而,SED受到其星际介质中尘埃的显著影响。尘埃主要由渐近巨星分支星和II型超新星产生。此外,尘埃质量通过金属吸积而增加,并且颗粒之间的碰撞使颗粒尺寸发生变化。每个过程的贡献和消光取决于粒度分布。因此,SED模式应处理的尘埃质量和粒度分布的演变。尽管尘埃演化的重要性,许多以前的SED模型没有考虑总质量和尺寸分布的物理一致的方式的演变。在本工作中,我们建立了一个新的辐射转移SED模型,基于我们的尘埃演化模型符合化学演化。为了减少计算量,我们采用了巨颗粒和一维平面平行星系近似。作为一个基准案例,我们在闭盒模型下计算了不同年龄的类银河星系的SEDs。我们发现,年龄为1亿年的星系不会产生像多环芳烃这样的小颗粒。在1~Gyr之后,我们观测到由于尘埃质量的迅速增加而引起的红外辐射和衰减的急剧增加。我们的新模型第一次可以适当地处理这种现象。该模型可用于SED拟合星系的任何演化阶段。

英文摘要:

The spectral energy distribution (SED) of galaxies provides fundamental information on the related physical processes. However, the SED is significantly affected by dust in its interstellar medium. Dust is mainly produced by asymptotic giant branch stars and Type II supernovae. In addition, the dust mass increases through the metal accretion, and the grain size changes by the collisions between the grains. The contribution of each process and the extinction depend on the size distribution. Therefore, the SED model should treat the evolution of the dust mass and size distribution. In spite of the importance of dust evolution, many previous SED models have not considered the evolution of the total mass and size distribution in a physically consistent manner. In this work, we constructed a new radiative transfer SED model, based on our dust evolution model consistent with the chemical evolution. To reduce the computational cost, we adopted the mega-grain and the one-dimensional plane parallel galaxy approximation. As a fiducial case, we calculated Milky Way-like galaxy SEDs at various ages under the closed-box model. We found that a galaxy at the age of 100~Myr does not produce small grains such as polycyclic aromatic hydrocarbons. After 1~Gyr, we observed a drastic increase of infrared emission and attenuation caused by a rapid increase of dust mass. This phenomenon can be treated appropriately for the first time by our new model. This model can be used for the SED fitting to a galaxy at any stage of evolution.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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