| タイトル | Emission from dust in visual reflection nebulae at infrared and submillimeter wavelengths |
| 著者（英） | Casey, Sean C. |
| 著者所属（英） | NASA Goddard Space Flight Center|Yerkes Observatory |
| 発行日 | 1991-04-10 |
| 言語 | eng |
| 内容記述 | Far-IR and submillimeter images of five bright visual reflection nebulae, IC 446, NGC2247, NGC 2245, NGC 7023, and CED 201 are presented and used with composite IR spectra to derive parameters such as the fraction of nebulae emission attributed to molecule-sized grains, the range of nebulae grain albedos, gas densities, and gas cloud geometries. The results show that 30-45 percent of the nebulae emission lies at wavelengths of less than 30 microns. The variation in IR luminosity may be related to variations in nebulae gas density and less than optimal gas cloud geometries rather than to anomalous grain albedos. Relative extinction efficincies of roughly 1000-5000 are inferred for stellar photospheres with effective wavelengths of roughly 0.25-0.5 micron. The resultant mass-extinction coefficient is roughly 10-50 sq cm/g. |
| NASA分類 | ASTROPHYSICS |
| レポートNO | 91A32919 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/348908 |
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