Extended Red Emission (ERE) in Planetary Nebulae

扩展红光发射(ERE)是一种尘埃发光过程，最近被归因于氢化无定形碳的光致发光。如果能够在银河系规模上证明它的存在，特别是在尘埃形成环境中，Ere必须被认为是一种重要的尘埃化合物存在和物理结构的直接观测证据，也就是无定形碳。行星状星云被认为是新的星际尘埃的主要来源之一，有一些证据表明，REE很可能存在于其中的许多天体中。行星状星云也展示了大量尘埃颗粒加工的证据。威特博士将对24个行星状星云的3200到10000埃波长范围内的光学连续体进行观测研究。他的目的是研究Ere的强度和光谱随这些星云中的碳氧比和存在的尘埃颗粒尺寸分布的函数而变化。

Extended red emission (ERE) is a dust luminescence process which has recently been attributed to photoluminescence by hydrogenated amorphous carbon. If its presence can be demonstrated on a galactic scale and, in particular, in dust forming environments, ERE must be considered direct observational evidence for the presence and physical structure of an important dust compound, that is, amorphous carbon. Planetary nebulae are recognized as one of the major sources of new interstellar dust, and there is some evidence that ERE is very likely to be present in many of these objects. Planetary nebulae also exhibit evidence for substantial dust grain processing. Dr. Witt will carry out observational studies of the optical continuum in the wavelength range of 3200 to 10,000 Angstroms of 24 planetary nebulae. His aim is to investigate the strength and the spectrum of ERE as a function of the carbon to oxygen ratio in these nebulae and as a function of the size distribution of the dust grains present.