Creating and Using Large Grids of Pre-calculated Model Atmospheres for Rapid Analysis of Stellar Spectra

Abstract

We present a database of 45,000 atmospheric models (which will become 80,000 models by the end of the project) with stellar masses between 9 and 120 M ⊙ , covering the region of the OB main sequence and W-R stars in the H-R diagram. The models were calculated using the ABACUS I supercomputer and the stellar atmosphere code CMFGEN. The parameter space has 6 dimensions: the effective temperature T eff , the luminosity L, the metallicity Z, and three stellar wind parameters, namely the exponent β , the terminal velocity V ∞ , and the volume filling factor F cl . For each model, we also calculate synthetic spectra in the UV (900-2000Å), optical (3500-7000Å), and near IR (10000-30000Å) regions. To facilitate comparison with observations, the synthetic spectra were rotationally broaden using ROTIN3, by covering v sin i velocities between 10 and 350 km/s with steps of 10 km/s, resulting in a library of 1 575 000 synthetic spectra. In order to demonstrate the benefits of employing the databases of pre-calculated models, we also present the results of the re-analysis of ε Ori by using our grid.