Re-detection and a Possible Time Variation of Soft X-ray Polarisation from the Crab
Abstract
The Crab nebula is so far the only celestial object with a statistically significant detection in soft x-ray polarimetry, a window that has not been explored in astronomy since the 1970s. However, soft x-ray polarimetry is expected to be a sensitive probe of magnetic fields in high energy astrophysical objects including rotation-powered pulsars and pulsar wind nebulae. Here we report the re-detection of soft x-ray polarisation after 40 years from the Crab nebula and pulsar with PolarLight, a miniature polarimeter utilising a novel technique onboard a CubeSat. The polarisation fraction of the Crab in the on-pulse phases was observed to decrease after a glitch of the Crab pulsar on July 23, 2019, while that of the pure nebular emission remained constant within uncertainty. The phenomenon may have lasted about 100 days. If the association between the glitch and polarisation change can be confirmed with future observations, it will place strong constraints on the physical mechanism of the high energy emission and glitch of pulsars.
Keywords
Cite
@article{arxiv.2011.05487,
title = {Re-detection and a Possible Time Variation of Soft X-ray Polarisation from the Crab},
author = {Hua Feng and Hong Li and Xiangyun Long and Ronaldo Bellazzini and Enrico Costa and Qiong Wu and Jiahui Huang and Weichun Jiang and Massimo Minuti and Weihua Wang and Renxin Xu and Dongxin Yang and Luca Baldini and Saverio Citraro and Hikmat Nasimi and Paolo Soffitta and Fabio Muleri and Aera Jung and Jiandong Yu and Ge Jin and Ming Zeng and Peng An and Alessandro Brez and Luca Latronico and Carmelo Sgro and Gloria Spandre and Michele Pinchera},
journal= {arXiv preprint arXiv:2011.05487},
year = {2020}
}
Comments
Authors' version of an article published in Nature Astronomy on 11 May 2020. Link to the paper: https://www.nature.com/articles/s41550-020-1088-1