X-ray polarimetry of the Crab nebula with PolarLight: polarization recovery after the glitch and a secular position angle variation

Abstract

We report follow-up observations of the Crab nebula with the PolarLight X-ray polarimeter, which revealed a possible variation in polarization associated with a pulsar glitch in 2019. The new observations confirm that the polarization has recovered roughly 100 days after the glitch. With the new observations, we find that the polarization angle (PA) measured with PolarLight from the total nebular emission has a difference of 18.0 +- 4.6 (deg) from that measured 42 years ago with OSO-8, indicating a secular evolution of polarization with either the Crab nebula or pulsar. The long-term variation in PA could be a result of multiple glitches in the history, magnetic reconnection or movement of synchrotron emitting structures in the nebula, or secular evolution of the pulsar magnetic geometry.

ApJ Letters to appear

References in corpus (4)

• Re-detection and a Possible Time Variation of Soft X-ray Polarisation from the Crab
• The slow rise and recovery of the 2019 Crab pulsar glitch
• In-orbit Operation and Performance of the CubeSat Soft X-ray Polarimeter PolarLight
• Modeling the in-orbit background of PolarLight

Cited by in corpus (7)

• Probing magnetar emission mechanisms with spectropolarimetry
• X-ray Polarimetry of the accreting pulsar 1A~0535+262 in the supercritical state with PolarLight
• Pulsar Wind Nebulae
• Crab Pulsar: IXPE Observations Reveal Unified Polarization Properties Across Optical and Soft X-Ray Bands
• XL-Calibur measurements of polarised hard X-ray emission from the Crab
• A significant detection of X-ray Polarization in Sco X-1 with PolarLight and constraints on the corona geometry
• The HaloSat and PolarLight CubeSat Missions for X-ray Astrophysics