منابع مشابه
Upper limit on C 60 and C + 60 features in the ISO - SWS spectrum of the reflection nebula NGC 7023 ⋆
We present here the 7.0–8.7 μm spectrum of the bright reflection nebula NGC 7023. Our observations are made with the Short Wavelength Spectrometer (SWS) on the European satellite Infrared Space Observatory (ISO). The vibrational bands of the ionized fullerene C60 are expected at 7.11 and 7.51 μm, while those of the neutral fullerene C60 are expected at 7.0 and 8.45 μm. We estimate an upper limi...
متن کاملFluorescent Molecular Hydrogen in Reflection Nebulae Graduate Board Oral Examination
Molecular hydrogen plays an important role in many astrophysical environments, among which are photodissociation regions. A photodissociation region is a gas rich interstellar region, usually in close proximity to a hot central object such as a massive star or stellar remnant. Such a region has a strong ultraviolet continuum radiation field, an environment favorable for a variety of atomic and ...
متن کاملA Survey of Near Infrared Emission in Visual Reflection Nebulae
We present a survey for extended 2.2 μm emission in 20 new visual reflection nebulae, illuminated by stars with temperatures of 3,600 — 33,000 K. We detect extended 2.2 μm emission in 13 new nebulae, illuminated by stars with temperatures of 6,800 – 33,000 K. For most of these 13 nebulae we have measured J −K, H −K, and K −L, as well as obtaining surface brightness measurements at the wavelengt...
متن کاملStability of Small Grains in Hii Regions and Reflection Nebulae
We have analyzed IRAS data to assess the relative amounts of small and large grains in HH regions and reflection nebulae. Our most important finding is that no evidence for small grain destruction is seen in reflection nebulae, even for [high] values of the radiation energy density at which significant grain destruction apparently occurs in HH regions. This suggests that it is not only the tota...
متن کامل3D Reconstruction of Reflection Nebulae from a Single Image
This paper presents a method for reconstructing the 3D distribution of dust densities in reflection nebulae based on a single input image using an analysisby-synthesis approach. In a reflection nebula, light is typically emitted from a central star and then scattered and partially absorbed by the nebula’s dust particles. We model the light transport in this kind of nebulae by considering absorp...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2010
ISSN: 2041-8205,2041-8213
DOI: 10.1088/2041-8205/722/1/l54