A Significant Detection of X-ray Polarization in Sco X-1 with PolarLight and Constraints on the Corona Geometry

  title={A Significant Detection of X-ray Polarization in Sco X-1 with PolarLight and Constraints on the Corona Geometry},
  author={Xiangyun Long and Hua Feng and Hong Li and Jiahuan Zhu and Qiong Wu and Jiahui Huang and M. Minuti and Weichun Jiang and Dongxin Yang and Saverio Citraro and Hikmat Nasimi and Jiandong Yu and Ge Jin and Ming Zeng and Penghui An and Jiachen Jiang and Enrico Costa and Luca Baldini and Ronaldo Bellazzini and Alessandro Brez and Luca Latronico and Carmelo Sgro’ and Gloria Spandre and Michele Pinchera and Fabio Muleri and Paolo Soffitta},
  journal={The Astrophysical Journal Letters},
We report the detection of X-ray polarization in the neutron-star low-mass X-ray binary Scorpius (Sco) X-1 with PolarLight. The result is energy-dependent, with a nondetection in 3–4 keV but a 4σ detection in 4–8 keV; it is also flux-dependent in the 4–8 keV band, with a nondetection when the source displays low fluxes but a 5σ detection during high fluxes, in which case we obtain a polarization fraction of 0.043 ± 0.008 and a polarization angle of 52.°6 ± 5.°4. This confirms a previous… 

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