标题： 新见解：复杂的行星状星云Hen 2-113 显示英文标题

标题： New insights on the complex planetary nebula Hen 2-113

摘要： 我们报告了使用VLT/NACO、VLTI/MIDI、VLT/ISAAC和ESO 3.6米望远镜的TIMMI获得的行星状星云Hen 2-113的红外观测结果。 Hen 2-113显示出一个明显的环状结构叠加在一个更弥散的环境中，在L'（3.8$\mu$m）、M'（4.78$\mu$m）和8.7$\mu$m波段可见。 通过MIDI未能检测到该物体在8.7$\mu$m波段的清晰核心，也未发现N波段的条纹。 采用类似哑铃的几何模型对该天体结构进行了定性解释。 星云中的PAH含量也通过ISAAC和TIMMI观测进行了研究。 这表明PAH主要集中在哑铃状结构的两端以及星云的双极喷流中。 在L'波段，使用NACO在中心源周围发现了一个直径为$0.3\arcsec$的空洞。 从NACO数据得出中心源的L'和M'波段流量，显示与基于恒星模型和短波长数据预期的恒星辐射相比存在显著的红外过量。 该源在L'和M'波段的观测流量分别约为仅包括中心恒星模型预期值的300倍和800倍。 此外，在L'波段中心天体呈现为可分辨的，测量得到的FWHM约为155毫角秒。 这种红外过量可以通过来自一个由温度为 T$\sim$1000K 的热尘埃组成的星云的辐射来解释，总质量为 $\sim10^{-9}$ M$\_{\odot}$。 显示英文摘要

摘要： We report infrared observations of the planetary nebula Hen 2-113 obtained with VLT/NACO, VLTI/MIDI, VLT/ISAAC and TIMMI at the ESO 3.6m. Hen 2-113 exhibits a clear ring-like structure superimposed to a more diffuse environment visible in the L' (3.8$\mu$m), M' (4.78$\mu$m) and 8.7$\mu$m bands. No clear core at 8.7$\mu$m and no fringes through the N band could be detected for this object with MIDI. A qualitative interpretation of the object structure is proposed using a diabolo-like geometrical model. The PAH content of the nebula was also studied with ISAAC and TIMMI observations. This indicates that the PAHs are mostly concentrated towards the lobes of the diabolo and the bipolar lobes of the nebula. In L' band, a void $0.3\arcsec$ in diameter was discovered with NACO around the central source. The L' and M' fluxes from the central source were derived from NACO data indicating an important infrared excess with respect to the expected stellar emission based on stellar models and short wavelength data. The observed flux from this source in the L' and M' is about 300 and 800 times respectively than those expected from a model including only the central star. Moreover, the central object appears resolved in L' band with measured FWHM about 155 mas. This infrared excess can be explained by emission from a cocoon of hot dust (T$\sim$1000K) with a total mass $\sim10^{-9}$M$\_{\odot}$.