Detection of O2 Produced Abiotically on Habitable but Lifeless Planets around M-dwarfs

High atmospheric abundances of oxygen has been widely considered to be a reliable biosignature for life on exoplanets in the habitable zones of all types of stars. Recently it was proposed that the unique UV spectra of observed planet-hosting M dwarfs could lead to the buildup of molecular oxygen in the atmospheres of habitable but lifeless planets around these stars (Tian et al. 2014). However, the detectability of the accumulated O₂ was not modeled. In this work we developed a new line by line radiative transfer model based on HITRAN database and used the model to simulate the reflectivity in the visible and near IR range. We show that abiotically produced and maintained O₂ in the 0.2% level is observable at 13105 cm^-1 (0.76 μm) with the spectra resolution of 70.