Computational Tools for the Spectroscopic Analysis of White Dwarfs

Abstract

The spectroscopic features of white dwarfs are formed in the thin upper layer of their stellar photosphere. These features carry information about the white dwarf's surface temperature, surface gravity, and chemical composition (hereafter 'labels'). Existing methods to determine these labels rely on complex ab-initio theoretical models which are not always publicly available. Here we present two techniques to determine atmospheric labels from white dwarf spectra: a generative fitting pipeline that interpolates theoretical spectra with artificial neural networks, and a random forest regression model using parameters derived from absorption line features. We test and compare our methods using a large catalog of white dwarfs from the Sloan Digital Sky Survey (SDSS), achieving the same accuracy and negligible bias compared to previous studies. We package our techniques into an open-source Python module 'wdtools' that provides a computationally inexpensive way to determine stellar labels from white dwarf spectra observed from any facility. We will actively develop and update our tool as more theoretical models become publicly available. We discuss applications of our tool in its present form to identify interesting outlier white dwarf systems including those with magnetic fields, helium-rich atmospheres, and double-degenerate binaries.

11 pages, 7 figures. Accepted for publication in MNRAS; updated references

References in corpus (13)

• The Gaia mission
• The DESI Experiment Part I: Science,Targeting, and Survey Design
• The 100 pc White Dwarf Sample in the SDSS Footprint
• White dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 14
• $Gaia$ white dwarfs within 40 pc II: the volume-limited northern hemisphere sample
• SDSS-V: Pioneering Panoptic Spectroscopy
• New Grids of Pure-Hydrogen White-Dwarf NLTE Model Atmospheres \newline and the HST/STIS Flux Calibration
• A brief introductory guide to TLUSTY and SYNSPEC
• $\text{Gaia}$ white dwarfs within 40 pc I: spectroscopic observations of new candidates
• The Relationship Between Globular Cluster Mass, Metallicity, and Light Element Abundance Variations
• Magnesium abundances in cool metal-polluted white dwarfs
• A grid of Synthetic Spectra for Hot DA White Dwarfs and Its Application in Stellar Population Synthesis
• Line Profiles of the Calcium I Resonance Line in Cool Metal-polluted White Dwarfs

Cited by in corpus (3)

• A Gravitational Redshift Measurement of the White Dwarf Mass-Radius Relation
• Data-Driven Selection and Spectral Classification of White Dwarf Stars
• Properties and Asteroseismological analysis of a new ZZ ceti discovered by TMTS