Mixing above the proto-neutron star is believed to play an important role in the supernova engine, and this mixing results in a supernova explosion with asymmetries. Elements produced in the innermost ejecta, e.g., ${}^{56}$Ni and ${}^{44}$Ti, provide a clean probe of this engine. The production of ${}^{44}$Ti is particularly sensitive to the exact production pathway and, by understanding the available pathways, we can use ${}^{44}$Ti to probe the supernova engine. Using thermodynamic trajectories from a three-dimensional supernova explosion model, we review the production of these elements and the structures expected to form under the "convective-engine" paradigm behind supernovae. We compare our results to recent X-ray and $\gamma$-ray observations of the Cassiopeia A supernova remnant.

中文翻译：

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仙后座超新星遗迹中的钛和铁

原中子星上方的混合被认为在超新星引擎中起着重要作用，这种混合导致超新星爆炸不对称。在最里面的喷射物中产生的元素，例如 ${}^{56}$Ni 和 ${}^{44}$Ti，提供了对该引擎的清晰探测。${}^{44}$Ti 的产生对确切的产生路径特别敏感，通过了解可用路径，我们可以使用 ${}^{44}$Ti 来探测超新星引擎。使用来自三维超新星爆炸模型的热力学轨迹，我们回顾了这些元素的产生以及在超新星背后的“对流引擎”范式下预期形成的结构。我们将我们的结果与最近对仙后座 A 超新星遗迹的 X 射线和 $\gamma$ 射线观测进行比较。