0.7um band parameters primitive asteroids

Meeting the quality standards, we employed a Markov chain Monte Carlo (MCMC) algorithm to compute the albedo threshold, maximizing primitive asteroid inclusion. Utilizing one- and two-dimensional (1D and 2D) projections, along with dimensionality-reduction methods (such as PCA and UMAP), we identified primitive asteroid populations. We uncovered: (a) the first observational evidence linking UV absorption to the 0.7um band, tied to hydrated iron-rich phyllosilicates; and (b) a 2D space revealing a split in C-type asteroids based on spectral features, including UV absorption.

The computed average depth (3.5+/-1.0%) and center (0.70+/-0.03um) of the 0.7um absorption band for primitive asteroids observed with Gaia is in agreement with the literature values. In this paper, we shed light on the importance of the UV absorption feature to discriminate among different mineralogies (i.e., iron-rich phyllosilicates vs. iron-poor) or to identify taxonomies that are conflated in the visible (i.e., F-types vs. B-types).

We have shown that this is a promising region for diagnostic studies of the composition of primitive asteroids.