Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analytic formulas for frequency and size dependence of absorption and
  scattering efficiencies of astronomical polycyclic aromatic hydrocarbons   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
$(a^{-3.5})$ size distribution which is very much in use. The analytic formulas
were obtained for the graphite and silicate grains in wavelength range 1000\AA
- 22,500\AA 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
{\it vis a vis} carbonaceous classical grains has been examined.

24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an