Discovery of a variable energy-dependent X-ray polarization in the accreting neutron star GX 5−1
Discovery of a variable energy-dependent X-ray polarization in the accreting neutron star GX 5−1
We report on the coordinated observations of the neutron star low-mass X-ray binary (NS-LMXB) GX 5−1 in X-rays (IXPE, NICER, NuSTAR , and INTEGRAL), optical (REM and LCO), near-infrared (REM), mid-infrared (VLT VISIR), and radio (ATCA). This Z-source was observed by IXPE twice in March–April 2023 (Obs. 1 and 2). …