Gaia white dwarfs within 40 pc - III. Spectroscopic observations of new candidates in the Southern hemisphere

We present a spectroscopic survey of 248 white dwarf candidates within 40 pc of the Sun; of these 244 are in the Southern hemisphere. Observations were performed mostly with the Very Large Telescope (X-Shooter) and Southern Astrophysical Research Telescope. Almost all candidates were selected from Gaia Data Release 3 (DR3). We find a total of 246 confirmed white dwarfs, 209 of which had no previously published spectra, and two main-sequence star contaminants. Of these, 100 white dwarfs display hydrogen Balmer lines, 69 have featureless spectra, and two show only neutral helium lines. Additionally, 14 white dwarfs display traces of carbon, while 37 have traces of other elements that arc heavier than helium. We observe 35 magnetic white dwarfs through the detection of Zeeman splitting of their hydrogen Balmer or metal spectral lines. High spectroscopic completeness (> 97 percent) has now been reached, such that we have 1058 confirmed Gala DR3 white dwarfs out of 1083 candidates within 40 pc of the Sun at all declinations.

Automated summary

We conducted a spectroscopic survey of 248 white dwarf candidates within a distance of 40 pc from the Sun, with 244 of them located in the Southern hemisphere. Using the Very Large Telescope and Southern Astrophysical Research Telescope, we confirmed a total of 246 white dwarfs, with 209 having no previously published spectra. Among the identified white dwarfs, 100 display hydrogen Balmer lines, 69 have featureless spectra, and two show only neutral helium lines. Additionally, we observed 35 magnetic white dwarfs through Zeeman splitting of their spectral lines.