Observations and Modelling of DQ White Dwarfs

TL;DR

This paper reports spectropolarimetric observations and modelling of 12 DQ white dwarfs, focusing on fitting C2 absorption bands to determine atmospheric parameters, with ongoing challenges in temperature estimation.

Contribution

It introduces a modelling approach for DQ white dwarfs using spectropolarimetry and explores atmospheric configurations, including spots and stratification.

Findings

Successful fitting of C2 absorption bands to derive atmospheric parameters.

Identification of challenges in temperature estimation from Swan bands.

Application of Berdyugina et al. (2005) modelling method to DQ white dwarfs.

Abstract

We present spectropolarimetric observations and modelling of 12 DQ white dwarfs. Modelling is based on the method presented in Berdyugina et al. (2005). We use the model to fit the C_2 absorption bands to get atmospheric parameters in different configurations, including stellar spots and stratified atmospheres, searching for the best possible fit. We still have problem to solve before we can give temperature estimates based on the Swan bands alone.