Cool Stars 14 - Submitted Abstract # 248
This version created on 05 October 2006

A New Code for the Calculation of Spectra and Spectral Energy
Distributions from 3-D Hydro Simulations


Lars Koesterke, University of Texas at Austin
Carlos Allende Prieto, University of Texas at Austin
Ivan Hubeny, University of Arizona
David Lambert, L., University of Texas at Austin

We will present a newly developed Spectral Synthesis Code for the
calculation of spectra from 3-D time-dependent hydrodynamical
simulations.  Key features of the new code are :  
   i) the latest and most complete opacities are used, 
   ii) molecular opacities (continuum and lines) are accounted for, 
   iii) the continuum contribution (i.e. opacities and background
   radiation field) is treated correctly and frequency dependent
   (full radiation transfer) enabling investigations of spectral
   energy distributions (SED) especially in the UV where scattering
   is most important, 
   iv) lines blends (atomic and molecular) are treated correctly, 
   v) large number of angles are used for the integration of the
   flux.  
Consequently the code is not limited to the calculation of
normalized unblended line profiles.  We will revisit the Oxygen
abundance of the Sun derived from the forbidden [OI] line at
6300A.  Previous investigations (severely constricted by the
inability to handle line blends) led to a dramatic decrease of
the solar Oxygen abundance.  However, the abundance is not free
from suspicion due to a blend with a NiI line and uncertainties
of the continuum level.  The suspicion is aggravated by the fact
that oxygen abundances derived from this line and OI 7773A are
not in perfect agreement.  As a second application we will
present, for the first time, the SED of the Sun based on 3-D
simulations with coverage from the near-UV to the near-IR.  The
comparision with observations and with SED's derived from 1-D
Kurucz models will illuminate the advantages of the new
approach.

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