White dwarfs with infrared excess within 100 pc: Gaia and the Virtual Observatory - SSW

WHITE DWARFS WITH INFRARED EXCESS WITHIN 100 PC: GAIA AND THE VIRTUAL OBSERVATORY - RAQUEL MURILLO OJEDA

White dwarfs (WDs) are one of the most common objects in the universe. They are stellar remnants of low and intermediate mass stars, such as the Sun. WDs are compact objects, with typical masses around half a solar mass and planetary sizes. They are the key to understanding the composition and evolution of exoplanetary material around intermediate mass stars in their late stages of evolution.
In this talk we will describe the work aimed at identifying nearby (< 100 pc) WDs with infrared excess. Starting from the so far most complete volume-limited WD sample built from Gaia DR3 data (Jiménez-Esteban et al. 2023, 10.1093/mnras/stac3382), we used Gaia DR3 spectroscopic coefficients and GaiaXPy to obtain JPAS synthetic photometry. Using VOSA, a Virtual Observatory tool, we complemented JPAS photometry with infrared photometry gathered from astronomical archives. Then, we compared the SEDs to different atmosphere models to identify flux excess at infrared wavelengths.
Once we have got rid of the potential sources of contamination, the origin of the excess can be attributed to two causes: The presence of a low mass, cool companion or the existence of a circumstellar dust disk. Spectroscopic observations are required to discern between the two possible scenarios. This is why we started a follow-up program of the most promising candidates using the X-Shooter instrument at the Very Large Telescope. In this talk, we will show the first results obtained in this analysis.