These tables contain two columns. The first gives the wavelength in micron. The second the absorption opacity in cm^2/gram-of-refractory-dust.
_Note: This is NOT per gram of dust, but per gram of refractory dust (i.e. per gram of non-icy dust material). This is also the way in which the IDL program below will convert it into dustkappaosshenn.inp.
Steps:
The simple IDL code to convert from the tables from Ossenkopf to the RADMC-3D standard format is: make_opac.pro
Just do the following:
NOTE: The opacity tables of Ossenkopf & Henning only go down to 1 micron wavelength!
Therefore we have to extrapolate to shorter wavelength, because RADMC-3D needs to have the opacity also in the wavelength domain where the stars emit light. This is done in a very ad-hoc way, but I see no other way.
NOTE: Icy grains have a ice feature in the NIR. Be careful with this! If you see this feature in emission in your RADMC-3D model spectra, then you apparently heated up the dust to temperatures where the ice should, in reality, have long evaporated. Since RADMC-3D does not explicitly treat evaporation, this would give physically wrong results. The ice feature should NEVER be in emission! This feature can only be seen in absorption. The best way to deal with this is to first do a calculation with RADMC-3D with this icy dust, and then replace it with ice-free dust in all regions where the temperature turns out to be above, say, 100 K or so. Though please look at the phase diagram of water to find out at which pressures and temperatures ice can remain in solid form. See e.g. Bauer, I., Finocchi, F., Duschl, W. J., Gail, H.-P., & Schloder, J. P. 1997, A&A, 317, 273.
The opacity table database for dust opacities from the Ossenkopf & Henning 1994 paper is located at:
http://hera.ph1.uni-koeln.de/~ossk/Jena/tables.html
How works
These tables contain two columns. The first gives the wavelength in micron. The second the absorption opacity in cm^2/gram-of-refractory-dust.
_Note: This is NOT per gram of dust, but per gram of refractory dust (i.e. per gram of non-icy dust material). This is also the way in which the IDL program below will convert it into dustkappaosshenn.inp.
Steps:
Plot in python
import numpy as np import matplotlib.pyplot as plt data=np.loadtxt('dustkappa_osshenn.inp',skiprows=2)
plot wavelenght v/s absorption opacity in cm^2/gram-of-refractory-dust
plt.plot(data[:,0],data[:,1]) plt.xscale('log') plt.yscale('log') plt.xlabel("$\lambda\; [\mu\mathrm{m}]$") plt.ylabel("$\kappa\; [\mathrm{cm}^2/\mathrm{g}]$")
NOTE: The opacity tables of Ossenkopf & Henning only go down to 1 micron wavelength! Therefore we have to extrapolate to shorter wavelength, because RADMC-3D needs to have the opacity also in the wavelength domain where the stars emit light. This is done in a very ad-hoc way, but I see no other way.
NOTE: Icy grains have a ice feature in the NIR. Be careful with this! If you see this feature in emission in your RADMC-3D model spectra, then you apparently heated up the dust to temperatures where the ice should, in reality, have long evaporated. Since RADMC-3D does not explicitly treat evaporation, this would give physically wrong results. The ice feature should NEVER be in emission! This feature can only be seen in absorption. The best way to deal with this is to first do a calculation with RADMC-3D with this icy dust, and then replace it with ice-free dust in all regions where the temperature turns out to be above, say, 100 K or so. Though please look at the phase diagram of water to find out at which pressures and temperatures ice can remain in solid form. See e.g. Bauer, I., Finocchi, F., Duschl, W. J., Gail, H.-P., & Schloder, J. P. 1997, A&A, 317, 273.