Gaia white dwarfs with infrared excess I. The 100 pc catalogue

TL;DR

This study compiles the largest and most complete catalogue of 456 white dwarfs within 100 pc exhibiting infrared excess, aiding the understanding of debris disks and planetary material around these stars.

Contribution

It presents a new, comprehensive catalogue of infrared excess white dwarfs within 100 pc, with 75% being newly identified, significantly advancing the sample size for future studies.

Findings

Infrared excess fraction is 5.9-9.2%, higher than previous estimates.

Most infrared excess WDs are newly identified in this work.

The fraction of non-hydrogen atmosphere WDs increases with Gaia colour.

Abstract

The presence of infrared excess flux observed in white dwarfs (WDs) is related to the existence of debris disks or substellar companions. These systems provide important clues in the study of extrasolar planetary material and binary evolution. However, fully characterising their properties requires a statistically significant, complete sample. This work aims to identify a complete sample of WDs with infrared excess emission within 100 pc of the Sun. We built the spectral energy distributions (SEDs) of the WDs using synthetic photometry in 56 optical filters of the J-PAS system, generated from Gaia Data Release 3 low-resolution spectra and complemented with the latest infrared photometry available at the Virtual Observatory (VO). VOSA was used to fit the SEDs with different atmospheric WD models depending on the source spectral type. We visually checked optical and infrared images to identify contaminated photometry. We built a catalogue of 456 infrared excess WDs, of which 292 are robust identifications, and 164 are candidates. 351 ($\sim$75%) are new identifications. This implies a fraction of infrared excess WDs between 5.9$\pm$0.3% and 9.2$\pm$0.4%, higher than previous works, but in agreement with some more recent estimates. Furthermore, for the sample of infrared excess WDs, the fraction of sources with non-hydrogen atmosphere increases with the Gaia GBP-GRP colour, contrary to the general WD population. However, this result should be interpreted with caution. Additionally, a thorough comparison of our catalogue with those of previous studies was performed. The sample of WDs with infrared excess emission within 100 pc presented in this work is the largest, most complete and reliable to date. Due to their proximity, they are ideal targets for follow-up studies aimed at characterising circumstellar disks, substellar companions, and the composition of accreted planetary material.