AGN Emission Diffuse Dust Attenuation is Pinned to `dust2=1`

[elijahmathews]

Context

In AGN_DUST, the AGN emission spectrum is attenuated by the diffuse dust curve using the following line:

  !attenuate the AGN emission by the diffuse dust
  agnspeci = agnspeci*EXP(-attn_curve(spec_lambda,dust_type,pset))

The function attn_curve returns the shape of the attenuation curve (i.e., the optical depth per unit dust parameter), but it does not appear to be scaled by the actual diffuse dust optical depth parameter, dust2 (stored in pset%dust2).

Since attn_curve does not internally multiply its result by pset%dust2, the code above effectively attenuates AGN emission by a fixed optical depth corresponding to dust2=1.0, regardless of the user's actual dust2 setting.

Impact

This decouples the AGN obscuration from the host galaxy's diffuse dust properties. A user might set dust2=0.0 (a dust-free galaxy) or dust2=5.0 (a heavily obscured galaxy), but the AGN emission will always be attenuated by the same constant factor.

Proposed Fix

The attenuation should be scaled by the diffuse dust parameter dust2:

  !attenuate the AGN emission by the diffuse dust
  ! Scale by pset%dust2 to apply the correct optical depth
  agnspeci = agnspeci*EXP(-pset%dust2 * attn_curve(spec_lambda,dust_type,pset))