Iaria, R. https://orcid.org/0000-0003-2882-0927
Di Salvo, T. https://orcid.org/0000-0002-3220-6375
Anitra, A. https://orcid.org/0000-0002-2701-2998
Barra, F. https://orcid.org/0000-0001-5852-6740
Sanna, A. https://orcid.org/0000-0002-0118-2649
Maraventano, C. https://orcid.org/0009-0007-8593-5006
Miceli, C. https://orcid.org/0009-0005-1240-6985
Leone, W. https://orcid.org/0000-0002-4773-3370
Burderi, L. https://orcid.org/0000-0001-5458-891X
Funding for this research was provided by:
Istituto Nazionale di Astrofisica (PRIN-INAF 2019:)
Agenzia Spaziale Italiana (HERMES Pathfinder operazioni n. 2022-25-HH.06)
Article Title: A Mysterious Feature in the NICER Spectrum of 4U 1820-30: A Gravitationally Redshifted Absorption Line?
Journal Title: The Astrophysical Journal
Article Type: paper
Copyright Information: © 2026. The Author(s). Published by the American Astronomical Society.
Publication dates
Date Received: 2025-07-29
Date Accepted: 2025-11-24
Online publication date: 2026-02-03