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arXiv 2305.07652astro-ph.HEastro-ph.GA
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超新星遗迹如何冷却?——I. 形态、光学发射线和激波

How do supernova remnants cool? -- I. Morphology, optical emission lines, and shocks

Ekaterina I. Makarenko, Stefanie Walch, Seamus D. Clarke, Daniel Seifried, Thorsten Naab, Pierre C. Nürnberger, Tim-Eric Rathjen

AI总结:

本文提出用于 FLASH 代码的后处理模块,利用 MAPPINGS V 数据计算超新星遗迹激波加热气体的冷却辐射,发现光学发射线受复杂结构和视线吸收显著影响,为SNR观测分类提供了新工具。

摘要:

超新星(SNe)向星际介质中注入约 $10^{51}$ erg 的能量,从而对气体产生激波加热。这部分能量中的很大一部分随后通过辐射冷却损失掉。我们提出了一个用于 FLASH 代码的后处理模块,利用来自 MAPPINGS V 的碰撞激发数据来计算激波加热气体的冷却辐射。将此工具应用于模拟的超新星遗迹(SNR)时,我们发现大部分能量在极紫外(EUV)波段发射。然而,光学发射线($[$O III$]$、$[$N II$]$、$[$S II$]$、H$α$、H$β$)通常最易于观测。我们的激波探测方案表明,[S II] 和 [N II] 发射源于环绕 SNR 的薄壳层,而 [O III]、H$\ m α$ 和 H$\ m β$ 则源自 SNR 气泡内充满体积的热气体。我们发现,光学发射线受 SNR 复杂结构及其在天球平面投影的影响,因为沿视线方向的吸收可使逃逸的线光度降低 10% 至 80%。此外,为了在氧或硫 BPT 图上正确分类 SNR,必须扣除污染背景辐射。从我们的合成观测中获得的电子温度和密度与模拟结果吻合良好,但对假设的金属丰度非常敏感。

英文摘要:

Supernovae (SNe) inject $\sim 10^{51}$ erg in the interstellar medium, thereby shocking and heating the gas. A substantial fraction of this energy is later lost via radiative cooling. We present a post-processing module for the FLASH code to calculate the cooling radiation from shock-heated gas using collisional excitation data from MAPPINGS V. When applying this tool to a simulated SN remnant (SNR), we find that most energy is emitted in the EUV. However, optical emission lines ($[$O III$]$, $[$N II$]$, $[$S II$]$, H$α$, H$β$) are usually best observable. Our shock detection scheme shows that [S II] and [N II] emissions arise from the thin shell surrounding the SNR, while [O III], H$\rm α$, and H$\rm β$ originate from the volume-filling hot gas inside the SNR bubble. We find that the optical emission lines are affected by the SNR's complex structure and its projection onto the plane of the sky because the escaping line luminosity can be reduced by 10 -- 80\% due to absorption along the line-of-sight. Additionally, the subtraction of contaminating background radiation is required for the correct classification of an SNR on the oxygen or sulphur BPT diagrams. The electron temperature and density obtained from our synthetic observations match well with the simulation but are very sensitive to the assumed metallicity.

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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