Unveiling Chemical Enrichment in the A2029 Core with XRISM, XMM-Newton, and Chandra

Abstract We present new measurements of the chemical abundance pattern in the core of the nearby galaxy cluster Abell 2029 (A2029), based on XRISM observations with Resolve (37 ks) and Xtend (500 ks), combined with archival data from XMM-Newton (European Photon Imaging Camera (EPIC), Reflection Grating Spectrometer (RGS)) and Chandra. Fe abundances derived from Resolve, Xtend, and EPIC are broadly consistent, while RGS gives systematically lower values. Because the XRISM gate valve remained closed during these observations, Resolve spectral fitting is restricted to the 2–10 keV band, providing reliable constraints only for elements with strong lines in this band (S, Ar, Ca, Fe, Ni). Abundances of the α -elements are therefore derived using complementary observations from Xtend, EPIC, RGS, and Chandra. We construct an average X/Fe pattern in the cluster core by using Resolve exclusively for S/Fe, Ar/Fe, Ca/Fe, and Ni/Fe and RGS + Xtend for O/Fe. The Ne/Fe ratio is averaged from Xtend, EPIC, RGS, and Chandra measurements; Mg/Fe, from EPIC and Chandra measurements; and Si/Fe, from Xtend, EPIC, and Chandra. Comparison with the supernova yield models indicates that the observed abundance pattern in the A2029 core is best reproduced by a combination of core-collapsed yields from low-metallicity progenitors ( Z init = 0.001) and a sub-Chandrasekhar-mass, double-degenerate Type Ia model. Additionally, we find an excess in Ca abundance in the core of A2029 that cannot be reproduced by the standard supernova yield models.