Dust Grains in Reflection Nebulae
نویسندگان
چکیده
منابع مشابه
Stability 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 کاملInterstellar Dust Grains
This review surveys the observed properties of interstellar dust grains: the wavelength-dependent extinction of starlight, including absorption features, from UV to infrared; optical luminescence; infrared emission; microwave emission; optical, UV, and X-ray scattering by dust; and polarization of starlight and of infrared emission. The relationship between presolar grains in meteorites and the...
متن کاملDust Extinction in Compact Planetary Nebulae
The effects of dust extinction on the departure from axi-symmetry in the morphology of planetary nebulae (PNs) are investigated through a comparison of the radio free-free emission and hydrogen recombination line images. The dust exctinction maps of five compact PNs are derived using high-resolution (∼0. 1) Hα and radio images maps of the HST and VLA. These extinction maps are then analyzed by ...
متن کاملCosmic dust grains strike again
A detailed simulation of air showers produced by dust grains has been performed by means of the aires Monte Carlo code with the aim of comparing with experimental data. Our analysis indicates that extensive dust grain air showers must yet be regarded as highly speculative but they cannot be completely ruled out. PACS number(s): 98.70.Sa, 98.70.-f
متن کاملThe Spatial Distribution of Cool Dust in Planetary Nebulae
We have observed a sample of eleven PNe using the PHT-C100 camera on ISO, obtaining maps at 60 and 100 m. The PHT-32 mapping mode was used, resulting in images of the PNe and nearby sky background. A preliminary reduction of the data has conrmed that the radial extent of the cool dust in general is similar to the optical nebula. Two of the PN in our sample have been clearly resolved at 60 and 1...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1973
ISSN: 0074-1809
DOI: 10.1017/s0074180900054103