Panchromatic Calibration of Astronomical Observations with State-of-the-Art White Dwarf Model Atmospheres

TL;DR

This paper discusses the use of advanced white dwarf model atmospheres to improve the calibration of astronomical instruments across a broad spectrum, leveraging high-quality spectral data and sophisticated models.

Contribution

It introduces the application of TMAP model atmospheres for spectral analysis and calibration of instruments, enhancing accuracy across multiple energy ranges.

Findings

Improved flux calibration using white dwarf SEDs.

Successful spectral analysis of hot, compact stars.

Demonstrated application across various stellar types.

Abstract

Theoretical spectral energy distributions (SEDs) of white dwarfs provide a powerful tool for cross-calibration and sensitivity control of instruments from the far infrared to the X-ray energy range. Such SEDs can be calculated from fully metal-line blanketed NLTE model-atmospheres that are e.g. computed by the Tuebingen NLTE model-atmosphere package (TMAP) that has arrived at a high level of sophistication. TMAP was successfully employed for the reliable spectral analysis of many hot, compact post-AGB stars. High-quality stellar spectra obtained over a wide energy range establish a data base with a large number of spectral lines of many successive ions of different species. Their analysis allows to determine effective temperatures, surface gravities, and element abundances of individual (pre-)white dwarfs with very small error ranges. We present applications of TMAP SEDs for spectral analyses of hot, compact stars in the parameter range from (pre-) white dwarfs to neutron stars and demonstrate the improvement of flux calibration using white-dwarf SEDs that are e.g. available via registered services in the Virtual Observatory.