Identification of 30,000 White Dwarf-Main Sequence binaries candidates from Gaia DR3 BP/RP(XP) low-resolution spectra

TL;DR

This paper presents a new method using Gaia DR3 low-resolution spectra and machine learning to identify approximately 30,000 white dwarf-main sequence binary candidates across the sky, including many previously difficult to detect systems.

Contribution

The study introduces a novel, model-independent neural network and Gaussian Process Classification approach for identifying WDMS binaries from Gaia spectra, especially effective for systems dominated by the main-sequence star.

Findings

Identified ~30,000 WDMS binary candidates, including ~1,700 high-confidence systems.

70% of candidates with $M_{G} > 7$ show UV excess, confirming white dwarf presence.

Method effectively detects systems with dominant main-sequence spectra, challenging for traditional techniques.

Abstract

White dwarf-main sequence (WDMS) binary systems are essential probes for understanding binary stellar evolution and play a pivotal role in constraining theoretical models of various transient phenomena. In this study, we construct a catalog of WDMS binaries using Gaia DR3's low-resolution BP/RP (XP) spectra. Our approach integrates a model-independent neural network for spectral modelling with Gaussian Process Classification to accurately identify WDMS binaries among over 10 million stars within 1 kpc. This study identify approximately 30,000 WDMS binary candidates, including ~1,700 high-confidence systems confirmed through spectral fitting. Our technique is shown to be effective at detecting systems where the main-sequence star dominates the spectrum - cases that have historically challenged conventional methods. Validation using GALEX photometry reinforces the reliability of our classifications: 70\% of candidates with an absolute magnitude $M_{G} > 7$ exhibit UV excess, a characteristic signature of white dwarf companions. Our all-sky catalog of WDMS binaries expands the available dataset for studying binary evolution and white dwarf physics and sheds light on the formation of WDMS.