Proceedings of the XIII Bulgarian-Serbian Astronomical Conference (XIII BSAC) Velingrad, Bulgaria, October 3-7, 2022 Editors: Evgeny Semkov, Milan S. Dimitrijević, Momchil Dechev and Zoran Simić Publ. Astron. Soc. Rudjer Boković No 25, 2023, 53-62 STARK BROADENING OF Fe XXV LINES FOR NEUTRON STARS AND THEIR ENVIRONMENT INVESTIGATIONS MILAN S. DIMITRIJEVIĆ 1,2 , MAGDALENA D. CHRISTOVA 3 , CRISTINA YUBERO 4 and SYLVIE SAHAL-BRÉCHOT 2 1 Astronomical Observatory, Volgina 7, 11060 Belgrade, Serbia 2 LERMA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, 5 Place Jules Janssen, 92190 Meudon, France 3 Department of Applied Physics, FAMI, Technical University of Sofia, blvd. Kl. Ohridski 10, 1000 Sofia, Bulgaria 4 Departamento de Física, Campus de Rabanales Edif. C2, Universidad de Córdoba, E-14071 Córdoba, Spain E-mail: mdimitrijevic@aob.bg.ac.rs, mchristo@tu-sofia.bg, f62yusec@uco.es, sylvie.sahal-brechot@obspm.fr Abstract. Stark broadening parameters, full widths at half intensity maximum and shifts for important spectral lines of Fe XXV, broadened by electron-, proton- and Fe XXVII ions-impacts, have been calculated with the help of the semiclassical perturbation formalism, for plasma conditions of interest for neutron star atmospheres and their environment, as well as for inertial fusion plasma. Examples of obtained results and the corresponding discussion are presented. 1. INTRODUCTION Stark broadening of spectral lines, or broadening by collisions with charged particles is significant for many important topics in astrophysics as for example modelling of stellar plasma, analysis and synthesis of spectral lines, opacity, radiative transfer, abundance determination, gravity acceleration etc. In the conditions of neutron star atmospheres and their envirionment Stark broadening is the most important pressure broadening mechanism of spectral lines. In spite of importance of Stark broadening parameters for analysis and modelling of neutron star atmospheres and their environements, we can see in literature that they are calculated very approximately, and without taking into account the magnetic field (see e.g. Paerels, 1997). Madej (1989) and Majczyna et al. (2005), use for Stark broadening calculations in atmospheres of neutron stars 53