Taxonomy of 14 042 asteroids from Gaia DR3 reflectance spectra

Context . Asteroid reflectance spectra provide key constraints on surface composition. Gaia Data Release 3 (DR3) enables the study of 60 518 asteroids through near-ultraviolet (NUV) to visible reflectance spectra. Aims . Our aim is to classify asteroids using Gaia DR3 spectra and provide a homogeneous taxonomical framework. Owing to systematics affecting Gaia DR3 data, direct comparison with previous taxonomies has to be performed with caution; therefore, we developed a classification scheme tailored to Gaia and linked the resulting taxa to established classes. Methods . We selected the highest-quality spectra using Gaia DR3 quality flags and applied uncertainty thresholds to mitigate spectral artifacts, retaining over one-third of the original sample at the least noisy wavelengths. To improve compositional discrimination, we included albedo information, thus reducing the final sample to about one-fourth of its initial size. We then iteratively applied dimensionality reduction and clustering techniques to identify the spectral taxa. Results . We classified 14042 asteroids into 13 taxonomic classes: A, B, C, D, E, F, G, K, L, M, P, S, and V, representing an increase in three compared to the number of objects classified in previous spectral classifications. The largest relative increase was found for the K class. The inclusion of NUV wavelengths allowed the separation of B and F types within the C complex and facilitated the identification of G types. The dynamical distribution follows expected trends: S types dominate the inner and middle main belt; C-complex asteroids are prevalent in the outer main belt; and D types are prevalent beyond the main belt. Conclusions . We present a taxonomical classification of 14 042 asteroids based on Gaia DR3 reflectance spectra. NUV coverage is critical for disentangling primitive classes within the C complex. Although artifacts in Gaia DR3 require caution when one is comparing median spectra with other datasets, this classification provides a robust reference for future Gaia releases with larger observed samples.