标题： 年轻核心坍缩超新星遗迹E0102中的尘埃形成 显示英文标题

标题： Dust Formation in the young core-collapse supernova remnant E0102

摘要： 我们介绍了对大麦云中的年轻超新星遗迹E0102（SNR 1E0102.2-7219）的斯皮策IRS和IRAC观测结果。红外光谱显示Ne和O的抛射物线很强，其中[Ne II]线在12.8微米处具有2,000-4,500 km/s的大速度弥散，表明有高速运动的抛射物。与年轻的银河系SNR Cas A不同，E0102缺乏Ar和Fe的发射。观测到的[Ne III]线对的诊断表明，[Ne III]发射的抛射物温度较低，为650 K，而[Ne V]线对表明红外[Ne V]发射的抛射物密度较高，约为~10^4/cm3。我们计算了包括光电离效应的各种速度范围的辐射冲击模型。冲击模型表明，[Ne V]线主要来自热且密集的冷却区，而[Ne II]和[Ne III]主要来自温度较低（400-1000 K）的光电离区。我们从红外观测中估计出红外发射的Ne抛射物质量为0.04 Msun，并讨论了对前身星质量的影响。光谱还具有一个在18微米处达到峰值的尘埃连续谱特征，该特征与抛射物在空间上一致，提供了尘埃在膨胀抛射物中形成的证据。18微米峰值的尘埃特征由MgSiO3和Si尘埃颗粒的混合物拟合，而其余的连续谱需要碳或Al2O3颗粒。我们测量到E0102抛射物中形成的总尘埃质量约为0.014 Msun。因此，E0102中的尘埃质量比Cas A小几倍。尘埃成分也不同，显示出相对较少的硅酸盐，且可能没有含铁的尘埃，这由缺乏铁发射的抛射物所暗示。 显示英文摘要

摘要： We present Spitzer IRS and IRAC observations of the young supernova remnant E0102 (SNR 1E0102.2-7219) in the Small Magellanic Cloud. The infrared spectra show strong ejecta lines of Ne and O, with the [Ne II] line at 12.8 microns having a large velocity dispersion of 2,000-4,500 km/s indicative of fast-moving ejecta. Unlike the young Galactic SNR Cas A, E0102 lacks emission from Ar and Fe. Diagnostics of the observed [Ne III] line pairs imply that [Ne III] emitting ejecta have a low temperature of 650 K, while [Ne V] line pairs imply that the infrared [Ne V] emitting ejecta have a high density of ~10^4/cm3. We have calculated radiative shock models for various velocity ranges including the effects of photoionization. The shock model indicates that the [Ne V] lines come mainly from the cooling zone, which is hot and dense, whereas [Ne II] and [Ne III] come mainly from the photoinization zone, which has a low temperature of 400-1000 K. We estimate an infrared emitting Ne ejecta mass of 0.04 Msun from the infrared observations, and discuss implications for the progenitor mass. The spectra also have a dust continuum feature peaking at 18 microns that coincides spatially with the ejecta, providing evidence that dust formed in the expanding ejecta. The 18-micron-peak dust feature is fitted by a mixture of MgSiO3 and Si dust grains, while the rest of the continuum requires either carbon or Al2O3 grains. We measure the total dust mass formed within the ejecta of E0102 to be ~0.014 Msun. The dust mass in E0102 is thus a factor of a few smaller than that in Cas A. The composition of the dust is also different, showing relatively less silicate and likely no Fe-bearing dust, as is suggested by the absence of Fe-emitting ejecta.