A grid of Synthetic Spectra for Hot DA White Dwarfs and Its Application in Stellar Population Synthesis

TL;DR

This paper introduces a comprehensive grid of synthetic spectra for hot DA white dwarfs, useful for stellar parameter determination and population synthesis, covering a wide temperature and gravity range with applications in integrated light studies.

Contribution

The work provides a new extensive spectral grid for hot DA white dwarfs, including LTE and non-LTE models, with synthetic magnitudes and applications in stellar population modeling.

Findings

Spectral grid covers 17,000 K to 100,000 K and log(g) 7.0 to 9.5.

Synthetic magnitudes for various telescopes and filters are derived.

DA white dwarfs may be detectable in ultraviolet for populations older than 8 Gyr.

Abstract

In this work we present a grid of LTE and non-LTE synthetic spectra of hot DA white dwarfs (WDs). In addition to its usefulness for the determination of fundamental stellar parameters of isolated WDs and in binaries, this grid will be of interest for the construction of theoretical libraries for stellar studies from integrated light. The spectral grid covers both a wide temperature and gravity range, with 17,000 K <= T_eff <= 100,000 K and 7.0 <= log(g) <= 9.5. The stellar models are built for pure hydrogen and the spectra cover a wavelength range from 900 A to 2.5 microns. Additionally, we derive synthetic HST/ACS, HST/WFC3, Bessel UBVRI and SDSS magnitudes. The grid was also used to model integrated spectral energy distributions of simple stellar populations and our modeling suggests that DAs might be detectable in ultraviolet bands for populations older than ~8 Gyr.