Rayleigh scattering

[HajimeKawahara]

Rayleigh scattering cross section added.
#115

Comparison and example

import pandas as pd
import matplotlib.pyplot as plt
dat = pd.read_csv("22-1.0E+00bar_1.0E+00.dat", delimiter="\s", names=("wav","null","null2","xs"))
N=100
wav = dat["wav"][::N]
xs  = dat["xs"][::N]

from exojax.spec.rayleigh import xsvector_rayleigh_gas
from exojax.spec.unitconvert import wav2nu
from exojax.atm.polarizability import polarizability

#p = 1.7403e-24
p = polarizability["N2"]
nus = wav2nu(wav, unit="um")
xs_exojax = xsvector_rayleigh_gas(nus, p, king_factor=1.0)

features

• spec.rayleigh.xsvector_rayleigh_gas
  Rayleigh scattering cross section from polarizability,
• spec.rayleigh.xsvector_rayleigh_gas_from_refractive_index
  Rayleigh scattering cross section from refractive index and number density

Also, I added polarizability and King correction at atm.polarizability

[ykawashima]

Thank you! I have confirmed that xsvector_rayleigh_gas works.