Faint white dwarf flux standards: data and models

TL;DR

This paper expands the CALSPEC database with 19 faint white dwarf standards, providing UV spectrophotometry and model fits to improve flux calibration accuracy for large telescopes up to JWST wavelengths.

Contribution

It introduces new faint white dwarf flux standards with UV spectra and model fits, enhancing calibration resources for current and future telescopes.

Findings

Added 19 faint white dwarf standards to CALSPEC

Provided UV spectrophotometry between 1150-3000 Å

Constructed model SEDs covering 900 Å to 30 μm

Abstract

Fainter standard stars are essential for the calibration of larger telescopes. This work adds to the CALSPEC (calibration spectra) database 19 faint white dwarfs (WDs) with all-sky coverage and V magnitudes between 16.5 and 18.7. Included for these stars is new UV (ultraviolet) HST (Hubble Space Telescope) STIS (Space Telescope Imaging Spectrometer) spectrophotometry between 1150 and 3000~\AA\ with a resolution of $\sim$500. Pure hydrogen WD models are fit to these UV spectra and to six-band HST/WFC3 (Wide Field Camera 3) photometry at 0.28 to 1.6~\micron\ to construct predicted model SEDs (spectral energy distributions) covering wavelengths from 900~\AA\ to the JWST (James Webb Space Telescope) limit of 30~\micron\ using well-established CALSPEC procedures for producing flux standards with the goal of 1\% accuracy.