English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We report on observations of the polarization of optical and {\gamma}-rayphotons from the Crab nebula and pulsar system using the Galway AstronomicalStokes Polarimeter (GASP), the Hubble Space Telescope/Advanced Camera forSurveys (HST/ACS) and the International Gamma-Ray Astrophysics Laboratorysatellite (Integral). These, when combined with other optical polarizationobservations, suggest that the polarized optical emission and {\gamma}-raypolarization changes in a similar manner. A change in the optical polarizationangle has been observed by this work, from 109.5 \pm 0.7\deg in 2005 to 85.3\pm 1.4 \deg in 2012. On the other hand, the {\gamma}-ray polarization anglechanged from 115 \pm 11 \deg in 2003-2007 to 80 \pm 12 \deg in 2012-2014.Strong flaring activities have been detected in the Crab nebula over the pastfew years by the high energy {\gamma}-ray missions Agile and Fermi, andmagnetic reconnection processes have been suggested to explain theseobservations. The change in the polarized optical and {\gamma}-ray emission ofthe Crab nebula/pulsar as observed, for the first time, by GASP and Integralmay indicate that reconnection is possibly at work in the Crab nebula. We alsoreport, for the first time, a non-zero measure of the optical circularpolarization from the Crab pulsar+knot system.

A recent change in the optical and {\gamma}-ray polarization of the Crab nebula and pulsar