Work

X-Ray Polarization Study of the Neutron Star Low-mass X-Ray Binary GX 349+2

Year: 2025

Type: article

Abstract: We report the first X-ray polarimetric results of the neutron star (NS) low-mass X-ray binary Z-source GX 349+2 using the Imaging X-ray Polarimetry Explorer (IXPE). We discovered that the X-ray source was polarized at a polarization degree of PD = 1.1% ± 0.3% (1σ errors) with a polarization angle of PA = 32° ± 6° (1σ errors). Simultaneous Nuclear Spectroscopic Telescope Array observations show that the source transitioned through the normal branch, flaring branch, and soft apex of the Z-track during our IXPE observations. The X-ray spectropolarimetry results suggest a source geometry comprising an accretion disk component, a blackbody representing the emission from the NS surface, and a Comptonized component. We discuss the accretion geometry of the Z-source in light of the spectropolarimetric results.

Source: The Astrophysical Journal

DOI: 10.3847/1538-4357/adda35

Authors: Unnati Kashyap, Thomas J. Maccarone, Mason Ng, Eliot C. Pattie, Swati Ravi, Herman L. Marshall

Institutions: Texas Tech University, Trottier Space Institute at McGill, McGill University, Massachusetts Institute of Technology

Language: English

Topic: Astrophysical Phenomena and Observations

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $4,499

Funders: National Aeronautics and Space Administration, Goddard Space Flight Center, Fonds de recherche du Québec – Nature et technologies