کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5429250 | 1397341 | 2012 | 8 صفحه PDF | دانلود رایگان |

In a series of two recent papers, the frequency and size distribution dependence of extinction spectra for astronomical silicate and graphite grains was analyzed by us in the context of MRN type interstellar dust models. These grains were taken to be homogeneous spheres following the power law (aâ3.5) size distribution which is very much in use. The analytic formulas were obtained for the graphite and silicate grains in wavelength range 1000Â Ã -22,500Â Ã and their utility was demonstrated. In this paper of the series, we present analytic formulas for the scattering and absorption spectrum of another important constituent of interstellar dust models, namely, the polycyclic aromatic hydrocarbons (PAHs). Relative contribution of the PAHs to extinction vis a vis carbonaceous classical grains has been examined.
⺠Wavelength range 1000à â¤Î»â¤22,500à , PAH size range 5à â¤aâ¤50à a is radius. ⺠Formulas can be used for computing extinction spectra of some bulk PAHs material. ⺠Slight difference in extinction behavior of ionic and neutral PAHs. ⺠Range of λ over which absorption efficiency differ depend on the PAH radius. ⺠Comparing efficiency of equal volume of graphite â¥,⥠& PAH shows its importance in model.
Journal: Journal of Quantitative Spectroscopy and Radiative Transfer - Volume 113, Issue 8, May 2012, Pages 624-631