论文标题
围绕不断发展的恒星的环和弧形。 ii。碳星AFGL 3068和行星Nebulae NGC 6543，NGC 7009和NGC 7027
Rings and arcs around evolved stars. II. The Carbon Star AFGL 3068 and the Planetary Nebulae NGC 6543, NGC 7009 and NGC 7027
论文作者
论文摘要
我们介绍了行星星云（PNE）NGC 6543，NGC 7009和NGC 7027的弧形和类似环形的特征的详细比较研究，以及碳恒星AFGL 3068周围的螺旋模式，使用高质量的多层HST HST图像。这种比较使我们能够研究AGB恒星周围的常规图案与PNE周围的不规则同心模式之间的连接和可能演变。发现这些特征的径向正确运动（约15 km/s）与AGB风及其线性尺寸和横向间时（500-1900年）一致，也与周围AGB恒星周围发现的那些一致，这表明是常见的起源。我们发现使用辐射流动力学模拟的证据表明，在AGB阶段结束时产生的规则模式因其与膨胀的PN的相互作用以及各向异性照明和由阴影不稳定性引起的电离模式而高度扭曲。这些过程将破坏AGB恒星周围的规则（主要是螺旋）模式，在PNE的光环中观察到了弧形和碎片环。
We present a detailed comparative study of the arcs and fragmented ring-like features in the haloes of the planetary nebulae (PNe) NGC 6543, NGC 7009, and NGC 7027 and the spiral pattern around the carbon star AFGL 3068 using high-quality multi-epoch HST images. This comparison allows us to investigate the connection and possible evolution between the regular patterns surrounding AGB stars and the irregular concentric patterns around PNe. The radial proper motion of these features, ~15 km/s, are found to be consistent with the AGB wind and their linear sizes and inter-lapse times (500-1900 yr) also agree with those found around AGB stars, suggesting a common origin. We find evidence using radiative-hydrodynamic simulations that regular patterns produced at the end of the AGB phase become highly distorted by their interactions with the expanding PN and the anisotropic illumination and ionization patterns caused by shadow instabilities. These processes will disrupt the regular (mostly spiral) patterns around AGB stars, plausibly becoming the arcs and fragmented rings observed in the haloes of PNe.
