H-band temperature and metallicity indicators for cool giants empirical relations in bayesian framework

ABSTRACT We explored here the near-infrared H-band atmospheric window aiming to provide quantitative diagnostic tools for deriving stellar parameters, instance, effective temperature (Teff) and metallicity ([Fe/H]), of cool giants (Teff < 5000 K) using low-resolution spectra. obtained 177 from X-shooter spectral library covering a wider range (−2.35 dex [Fe/H] 0.5 dex) than in earlier works. Degrading resolution R ∼ 1200, we estimated equivalent widths several important features, behaviour features with parameters are studied. Also, empirical relations Teff established Bayesian framework. found that 12CO at 1.56 1.62 $\mu$m, + MgI 1.71 $\mu$m best threeTeff indicators typical accuracy 153, 123, 107 K, respectively. The cubic model provides estimator 0.22, 0.28, 0.24 FeH 1.64 Fe I 1.66 also showed detailed dependence ofTeff–EWs correlations defining three groups, supersolar ([Fe/H] > 0.0 dex), solar (−0.3 0.3 subsolar <−0.3 Hierarchical modelling. difference between relationship is statistically significant, but such not evident groups.