Shah, ChintanAmaro, PedroGrilo, FilipeGu, Ming FengGu, LiyiSantos, José PauloPorter, F. ScottPfeifer, ThomasLeutenegger, Maurice A.López-Urrutia, José R. Crespo2025-08-192025-08-192025-07-01PURE: 119598993PURE UUID: a7f92069-a417-4122-9726-ed268599ac64ORCID: /0000-0002-5257-6728/work/186629923Scopus: 105009103585ORCID: /0000-0002-5890-0971/work/190142859http://hdl.handle.net/10362/186633Research was funded by the Max-Planck-Gesselschaft (MPG), Germany. C.S. acknowledges support from MPG and NASA-JHU Cooperative Agreement. M.F.G. acknowledges support by NASA under APRA grant 80NSSC 20K0835. M.A.L. and F.S.P. acknowledge support from the NASA Astrophysics Program. © 2025. The Author(s). Published by the American Astronomical Society.We report on comprehensive laboratory studies of the K-shell dielectronic recombination resonances of Fe xxv-xxi ions that prominently contribute to the hard X-ray spectrum of hot astrophysical plasmas. By scanning a monoenergetic electron beam to resonantly excite trapped Fe ions in an electron beam ion trap and achieving a high electron-ion collision energy resolution of ∼7 eV, we resolve their respective KLn satellites up to n ′ = 11 . By normalization to known radiative recombination cross sections, we also determine their excitation cross sections and that of the continuum with uncertainties below 15% and verify our results with an independent normalization based on previous measurements. Our experimental data excellently confirm the accuracy and suitability of distorted-wave calculations obtained with the Flexible Atomic Code for modeling astrophysical and fusion plasmas.1652122engjournal article10.3847/1538-4357/addabahttps://doi.org/10.3847/1538-4357/addabahttps://www.scopus.com/pages/publications/105009103585