Spectropolarimetric observations of cool DQ white dwarfs

TL;DR

This study uses spectropolarimetric data to investigate magnetic fields in a sample of 11 cool DQ white dwarfs, identifying potential magnetic features and highlighting the need for further observations to confirm findings.

Contribution

It presents new spectropolarimetric observations of DQ white dwarfs, including the discovery of potential magnetic signatures in one object, expanding understanding of magnetism in these stars.

Findings

Detection of continuum circular polarization in WD1235+422

Potential magnetic field indications in one DQ WD

Further observations needed for confirmation

Abstract

Following our recent discovery of a new magnetic DQ white dwarf (WD) with CH molecular features, we report the results for the rest of the DQ WDs from our survey. We use high signal-to-noise spectropolarimetric data to search for magnetic fields in a sample of 11 objects. One object in our sample, WD1235+422, shows the signs of continuum circular polarization that is similar to some peculiar DQs with unidentified molecular absorption bands, but the low S/N and spectral resolution of these data make more observations necessary to reveal the true nature of this object.