The structure of the relativistic Fe line in GX 340+0 as viewed with XRISM/Resolve, NICER, and NuSTAR
Abstract We present a $152$ ks XRISM/Resolve observation of the persistently accreting Z source GX 340$+$0. Simultaneous observations also occurred with NuSTAR and NICER for $22.47$ ks and $2.7$ ks, respectively. The source covered the normal branch to the flaring branching during the observations. The data from all three missions were modeled concurrently for each spectral branch. The superior energy resolution of XRISM/Resolve reveals structure within the iron emission line complex regardless of spectral state. We model the reprocessed Fe K line with a reflection model tailored for thermal illumination of the accretion disk by a neutron star. The currently available model encompasses the broad components, but narrow emission features remain at the ${\sim}5\%$ level. These remaining features may be described by the presence of an ionized plasma in the system as has been observed in the Z source Cygnus X-2, but subsequent updates to the reflection model code may be able to explain these features.
Authors
- Lía Corrales (ORCID: https://orcid.org/0000-0002-5466-3817)
- Chris Done (ORCID: https://orcid.org/0000-0002-1065-7239)
- D. L. Moutard (ORCID: https://orcid.org/0000-0003-1463-8702)
- Javier A. García (ORCID: https://orcid.org/0000-0003-3828-2448)
- I. Psaradaki (ORCID: https://orcid.org/0000-0002-1049-3182)
- S. Malu (ORCID: https://orcid.org/0000-0003-0440-7978)
- Priyanka Chakraborty (ORCID: https://orcid.org/0000-0002-4469-2518)
- Randall K. Smith (ORCID: https://orcid.org/0000-0003-4284-4167)
- F. S. Porter (ORCID: https://orcid.org/0000-0002-6374-1119)
- Ralf Ballhausen (ORCID: https://orcid.org/0000-0002-1118-8470)
- R. M. Ludlam (ORCID: https://orcid.org/0000-0002-8961-939X)
- Takao Nakagawa (ORCID: https://orcid.org/0000-0002-6660-9375)
- E. Costantini (ORCID: https://orcid.org/0000-0001-8470-749X)
- H. Takahashi (ORCID: https://orcid.org/0000-0001-6314-5897)
- Caroline A. Kilbourne (ORCID: https://orcid.org/0000-0001-9464-4103)
- Hayden Hall
Institutions
- Hiroshima University (JP)
- California Institute of Technology (US)
- Goddard Space Flight Center (US)
- Tokyo City University (JP)
- Wayne State University (US)
- Durham University (GB)
- University of Michigan (US)
- Japan Aerospace Exploration Agency (JP)
- Center for Astrophysics Harvard & Smithsonian (US)
- Institute of Space and Astronautical Science (JP)
- Space Research Organisation Netherlands (NL)
- Massachusetts Institute of Technology (US)
- University of Maryland, College Park (US)
Publication Details
- Journal
- Publications of the Astronomical Society of Japan
- Published
- 2025-08-11
- DOI
- https://doi.org/10.1093/pasj/psaf085
- Citations
- 2
- Primary Topic
- Astrophysical Phenomena and Observations
- Type
- article
- Field-Weighted Citation Impact
- 2.31
Funders
- National Aeronautics and Space Administration
- Smithsonian Astrophysical Observatory
- Japan Society for the Promotion of Science