Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radiative transfer in disc galaxies $-$ V. The accuracy of the KB
  approximation   We investigate the accuracy of an approximate radiative transfer technique
that was first proposed by Kylafis & Bahcall (hereafter the KB approximation)
and has been popular in modelling dusty late-type galaxies. We compare
realistic galaxy models calculated with the KB approximation with those of a
three-dimensional Monte Carlo radiative transfer code SKIRT. The SKIRT code
fully takes into account of the contribution of multiple scattering whereas the
KB approximation calculates only single scattered intensity and multiple
scattering components are approximated. We find that the KB approximation gives
fairly accurate results if optically thin, face-on galaxies are considered.
However, for highly inclined ($i \gtrsim 85^{\circ}$) and/or optically thick
(central face-on optical depth $\gtrsim1$) galaxy models, the approximation can
give rise to substantial errors, sometimes, up to $\gtrsim 40\%$. Moreover, it
is also found that the KB approximation is not always physical, sometimes
producing infinite intensities at lines of sight with high optical depth in
edge-on galaxy models. There is no "simple recipe" to correct the errors of the
KB approximation that is universally applicable to any galaxy models.
Therefore, it is recommended that the full radiative transfer calculation be
used, even though it's slower than the KB approximation.

10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
2
The categories of this paper are: math