A Large Catalog of DA White Dwarf Characteristics Using SDSS and Gaia Observations

TL;DR

This paper provides the largest catalog of DA white dwarfs with spectroscopic and photometric data from SDSS and Gaia, validating measurements and analyzing systematic differences across survey generations.

Contribution

It introduces a comprehensive, publicly available catalog of over 27,000 DA white dwarfs with validated measurements and investigates systematic survey discrepancies.

Findings

Measurements agree within 7.5 km/s, 0.060 dex, and 2.4% for high S/N spectra.

Gaia photometry measurements agree within 0.0005 R_sun and 3%.

Systematic differences in parameters are observed between SDSS survey generations.

Abstract

We present a catalog of 8545 and 19,257 unique DA white dwarfs observed in SDSS Data Release 19 and previous SDSS data releases, respectively. This is the largest catalog of both spectroscopic and photometric measurements of DA white dwarfs available to date, and we make this catalog and all code used to create it publicly available. We measure the apparent radial velocity, spectroscopic effective temperature and surface gravity, and photometric effective temperature and radius for all objects in our catalog. We validate our measurements against other published white dwarf catalogs. For apparent radial velocities, surface gravities, and effective temperatures measured from spectra with signal-to-noise ratios $>50$, our measurements agree with published SDSS white dwarf catalogs to within 7.5 km/s, 0.060 dex, and $2.4\%$, respectively. For radii and effective temperatures measured with Gaia photometry, our measurements agree with other published Gaia datasets to within $0.0005$ $R_\odot$ and $3\%$, respectively. We use this catalog to investigate systematic discrepancies between white dwarfs observed in SDSS-V and previous generations of SDSS. For objects observed in both SDSS-V and previous generations, we uncover systematic differences between measured spectroscopic parameters depending on which set of survey data is used. On average, the measured apparent radial velocity of a DA white dwarf is $11.5$ km/s larger and the surface gravity is $0.015$ dex smaller when a white dwarf's spectroscopic parameters are measured using SDSS-V data compared to using data from previous generations of SDSS. These differences may be due to changes in the wavelength solution across survey generations.