High-resolution X-ray spectroscopy with XRISM/Resolve reveals super-solar abundance ratios in Virgo/M87

Context. The chemical composition of the intracluster medium (ICM) provides key insights into the enrichment history of galaxy clusters. However, high-resolution abundance measurements with X-ray microcalorimeters remain available for only a few systems. While most cool-core clusters exhibit near-solar elemental abundance ratios relative to Fe, previous studies of the Virgo cluster have suggested super-solar ratios in its core. Aims. We investigate the chemical properties of the Virgo cluster core using XRISM/Resolve observations, focusing on precise measurements of Si, S, Ar, Ca, Cr, Fe, and Ni abundances. We aim to determine whether Virgo displays abundance patterns distinct from other nearby cool-core clusters and to explore the physical origin of any differences. Methods. We analyzed full field-of-view XRISM/Resolve spectra in four regions of the Virgo core (center, east, northwest, and southwest) in the 1.7–11 keV band. Single-temperature, multi-temperature, and multi-abundance models were applied to characterize the thermal structure and derive elemental abundances. The resulting abundance ratios were compared between pointings, with previous studies of Virgo/M87, and with recent XRISM measurements of other clusters. Results. All four pointings exhibit systematically super-solar X/Fe ratios, although the northwest region shows values closer to solar. Multi-abundance modeling of the eastern and southwestern regions reveals that cool, metal-rich gas uplifted by the AGN coexists with a hotter and more chemically homogeneous ambient ICM. The super-solar ratios are robust against variations in bandpass and temperature structure. We interpret these enhanced ratios as reflecting the enrichment history of the old stellar population in M87 combined with a limited cold gas reservoir. Conclusions. The Virgo core exhibits spatially resolved chemical enrichment that differs from the abundance patterns observed in other cool-core clusters. These results highlight the importance of high-resolution spectroscopy for disentangling AGN-driven transport, multi-phase structure, and stellar enrichment. Expanding microcalorimeter observations to a larger cluster sample will be essential to determine whether Virgo is an outlier or representative of a broader diversity in cluster-core enrichment histories.