fix bug for polar dust

pcigale/sed_modules/skirtor2016.py

@@ -138,9 +138,10 @@ class SKIRTOR2016(SedModule):
             # Keep the direct and scatter components for type-2
             disk_new = self.SKIRTOR2016.disk
         # Calculate the total extincted luminosity averaged over all directions
+        sin_oa = np.sin( self.oa*np.pi/180 )
         l_ext = np.trapz(self.SKIRTOR2016.intrin_disk * (1-ext_fac),
                          x=self.SKIRTOR2016.wave) * \
-                        (1 - np.sin( np.deg2rad(self.oa) ))
+                        (0.4931 - 0.2113*sin_oa**2 - 0.2818*sin_oa**3)
         # Casey (2012) modified black body model
         conv = self.c / (self.SKIRTOR2016.wave * self.SKIRTOR2016.wave)
         blackbody = (conv * (1. - np.exp(-(lambda_0 / self.SKIRTOR2016.wave)