The effective temperature scale of FGK stars. I. Determination of temperatures and angular diameters with the infrared flux method

Abstract

The infrared flux method (IRFM) has been applied to a sample of 135 dwarf and 36 giant stars covering the following regions of the atmospheric parameters space: 1) the metal-rich ([Fe/H]>0) end (consisting mostly of planet-hosting stars), 2) the cool (Teff<5000 K) metal-poor (-1<[Fe/H]<-3) dwarf region, and 3) the very metal-poor ([Fe/H]<-2.5) end. These stars were especially selected to cover gaps in previous works on Teff vs. color relations, particularly the IRFM Teff scale of A. Alonso and collaborators. Our IRFM implementation was largely based on the Alonso et al. study (absolute infrared flux calibration, bolometric flux calibration, etc.) with the aim of extending the ranges of applicability of their Teff vs. color calibrations. In addition, in order to improve the internal accuracy of the IRFM Teff scale, we recomputed the temperatures of almost all stars from the Alonso et al. work using updated input data. The updated temperatures do not significantly differ from the original ones, with few exceptions, leaving the Teff scale of Alonso et al. mostly unchanged. Including the stars with updated temperatures, a large sample of 580 dwarf and 470 giant stars (in the field and in clusters), which cover the ranges: 3600 K<Teff<8000 K, -4.0<[Fe/H]<+0.5, have Teff homogeneously determined with the IRFM. (Abridged)