An Integrated Iterative Spectral Synthesis Technique for Deriving Stellar Photosphere Parameters

We describe a procedure for determining the photospheric parameters of a star -- T_eff, log g, xi_micro, v sin i, v_r, and [X/H] for all relevant atomic species -- based solely on synthetic spectrum fits to its observed high-resolution spectrum. With a sufficient number of temperature- and gravity-dependent metal absorption lines, T_eff and log g can be derived without resort to photometry, spectrophotometry, or Balmer line profile fitting. Chemical abundances (including upper bounds on underabundant species) and photospheric velocities are calculated via the same iterative synthesis algorithms, yielding a homogenous and internally consistent solution. Although computationally intensive, this technique requires relatively little human oversight, and the bulk of the analysis can be run in batch mode. We present an overview of the procedure, and compare the results for a selection of test stars to parameters derived from other methods.