Spectroscopic observations of high proper motion DA white dwarfs

TL;DR

This study spectroscopically analyzed 70 high proper motion DA white dwarfs to determine their physical properties, kinematics, magnetic fields, and proximity to the Sun, enhancing understanding of local white dwarf populations.

Contribution

The paper provides detailed spectroscopic analysis of a significant sample of high proper motion DA white dwarfs, including magnetic field estimates and identification of nearby objects.

Findings

Most white dwarfs belong to the thin disk population

Identified three magnetic white dwarfs with estimated magnetic fields

Six white dwarfs are within 20 parsecs of the Sun

Abstract

We used the revised New Luyten Two-Tenths (rNLTT) catalog to select high proper motion white dwarf candidates. We studied the spectra of 70 hydrogen-rich (DA) white dwarfs, which were obtained at the Cerro Tololo Inter-American Observatory (CTIO) and extracted from the Sloan Digital Sky Survey (SDSS). We determined their effective temperature and surface gravity by fitting their Balmer line profiles to model white dwarf spectra. Using evolutionary mass-radius relations we determined their mass and cooling age. We also conducted a kinematical study of the white dwarf sample and found that most belong to the thin disk population. We have identified three magnetic white dwarfs and estimated their surface magnetic field. Finally, we have identified 6 white dwarfs that lie within 20 pc from the Sun.