A Grid of Synthetic Spectra for Subdwarfs: Non-LTE Line-blanketed Atmosphere Models

Abstract

A new grid of detailed atmosphere model spectra for hot and moderately cool subdwarf stars is presented. High-resolution spectra and synthetic photometry are calculated in the range from 1000–10,000 Å using non-LTE fully line-blanketed atmosphere structures. Our grid covers eight temperatures within 10,000 ≤ T eff [K] ≤ 65,000, three surface gravities in the range 4.5 ≤ log g [cgs] ≤ 6.5, two helium abundances matching two extreme helium-rich and helium-poor scenarios, and two limiting metallicity boundaries regarding both solar ([Fe/H] = 0) and Galactic halos ([Fe/H] = −1.5 and [ α /Fe] = +0.4). Besides its application in the determination of fundamental parameters of subdwarfs in isolation and in binaries, the resulting database is also of interest for population synthesis procedures in a wide variety of stellar systems.