论文标题
Cassiopeia a的弹出弹出中的元素丰度A
Element Abundances in the Unshocked Ejecta of Cassiopeia A
论文作者
论文摘要
我们分析和模拟了Cassiopeia的红外光谱，以确定未落后的喷射中各种元素的质量。通过这种方式，我们补充了Hwang＆Laming（2012）的X射线发射喷射的调查，以提供CAS A弹出的元素组成的完整人口普查。我们使用X射线和紫外线发射从正前向辐射和反向震动作为电离辐射来确定弹射器中各个元素的电离平衡，以确定射流中各个元素的电离平衡。假设所有发射线主要在最大化其发射的射出密度上激发，我们可以将观察到的线强度转换为元素质量。我们发现，$ \ sim 3 $ m_sun弹飞的大部分已经发生了反向冲击，今天在X射线中可以看到。少数族裔，$ \ sim 0.47 \ pm 0.05 $ m_sun，这里引用的不确定性仅来自数据拟合过程，仍在反向冲击内部扩展并在红外线中发射。该组件主要由O，Si和S组成，没有Fe易于检测到。估计的不确定性估计来自我们的建模，我们引用了$ 0.47 \ pm {0.47 \ at 0.24} $ m_sun。我们推测，根据Fe电荷态，内部喷射气体的弥漫性气体可能会出现进一步的0.07 m_sun fe。
We analyze and model the infrared spectrum of the Cassiopeia A supernova remnant, with the aim of determining the masses of various elements in the unshocked ejecta. In this way we complement the survey of the X-ray emitting ejecta of Hwang & Laming (2012) to provide a complete census of the elemental composition of the Cas A ejecta. We calculate photoionization-recombination equilibria to determine the ionization balance of various elements in the ejecta as a function of density, using the X-ray and UV emission from the forward and reverse shocks as the ionizing radiation. With the assumption that all emission lines are principally excited at the ejecta density that maximizes their emission, we can convert observed line intensities into element masses. We find that the majority of the $\sim 3 $M_sun ejecta have already been through the reverse shock and are seen today in X-rays. A minority, $\sim 0.47\pm 0.05$ M_sun, with uncertainties quoted here coming from the data fitting procedure only, are still expanding inside the reverse shock and emitting in the infrared. This component is comprised mainly of O, Si, and S, with no Fe readily detectable. Incorporating uncertainties estimated to come from our modeling, we quote $0.47 \pm {0.47\atop 0.24}$ M_sun. We speculate that up to a further 0.07 M_sun of Fe may be present in diffuse gas in the inner ejecta, depending on the Fe charge state.
