Spectroscopic Determination of Stellar Atmospheric Parameters: Application to Mid-F through Early-K Dwarfs and Subgiants

Abstract

Takeda et al.'s (2002, PASJ, 54, 451) method for the spectroscopic determination of stellar atmospheric parameters (T_eff, logg, v_t, and [Fe/H]) from the equivalent widths of Fe I and Fe II lines was applied to 32 dwarfs/subgiants of mid-F through early-K types based on high-quality echelle spectra obtained at Okayama Astrophysical Observatory, for the purpose of examining the numerical performance of this technique as well as the precision of the results. The solutions of the parameters were confirmed to successfully converge, except for a few cases (e.g., for lower temperature and lower metallicity stars) where the microturbulent velocity could not be well determined. A comparison of the present results with the literature values, especially those of Fuhrmann (1998, AAA070.155.024), revealed that the agreement is mostly satisfactory, though a systematic tendency appears to exist that our method yields slightly lower (i.e., by ∼ 100 K) T_eff values. The results are further discussed in relation to the stellar fundamental parameters (mass, luminosity, etc.), while referring to the Hipparcos parallaxes or theoretical stellar evolutionary tracks.