The Near Infrared FeH Lines as Indicators of Surface Gravity of M Stars
We compute synthetic spectra in the region around 1 μm, including the Wing-Ford band (WFB) of Iron Hydride (FeH) in the calculations. This band is known to be a good indicator of surface gravities of M stars. Employing Kurucz model atmospheres, we study the response of the intensity of the WFB to atmospheric parameters and check our results against observations of M dwarfs. This study is part of an ongoing project which aims to investigate the M dwarf-to-giant ratio in galaxies, through a population synthesis method, exploring a number of spectral indicators in the near infrared, such as the WFB, the NaI, CaII and CO near infrared features.