Related papers: Shedding new light on the Crab with polarized X-ra…
We have analyzed 16 years of observations dedicated to the Crab (pulsar + nebula) with the INTEGRAL SPI instrument to investigate its polarization properties. We find that the source presents a substantially polarized emission (PF = 24%) in…
We have measured the linear polarisation of hard X-ray emission from the Crab in a previously unexplored energy interval, 20-120 keV. The introduction of two new observational parameters, the polarisation fraction and angle stands to…
The Crab pulsar and its nebula are among the most studied astrophysical systems, and constitute one of the most promising environments where high energy processes and particle acceleration can be investigated. They are the only objects for…
We report measurements of the linear polarisation degree (PD) and angle (PA) for hard X-ray emission from the Crab pulsar and wind nebula. Measurements were made with the XL-Calibur ($\sim$15-80 keV) balloon-borne Compton-scattering…
The X/$\gamma$ ray polarimetry of the Crab pulsar/nebula is believed to hold crucial information on their emission models. In the past, several missions have shown evidence of polarized emission from the Crab. The significance of these…
Polarimetry is widely considered a powerful observational technique in X-ray astronomy, useful to enhance our understanding of the emission mechanisms, geometry and magnetic field arrangement of many compact objects. However, the lack of…
We present Crab X-ray polarization measurements using IXPE data with a total exposure of 300ks, three times more than the initial 2022 discovery paper. Polarization is detected in three times more pulsar phase bins, revealing an S-shaped…
Neutron stars generate powerful winds of relativistic particles that form bright synchrotron nebulae around them. Polarimetry provides a unique insight into the geometry and magnetic configuration of the wind, but high-energy measurements…
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…
Time-resolved polarisation measurements of pulsars offer an unique insight into the geometry of their emission regions. Such measure\ ments provide observational constraints on the different models proposed for the pulsar emission…
We present a phase-dependent analysis of the polarized emission from the Crab pulsar based on three sets of observations by the Imaging X-ray Polarimetry Explorer (IXPE). We found that a phenomenological model involving a simple linear…
In this paper we present, for the first time, simulated maps of the circularly polarized synchrotron emission from the Crab nebula, using multidimensional state of the art models for the magnetic field geometry. Synchrotron emission is the…
Recent observations of the polarisation of the optical pulses from the Crab pulsar motivated detailed comparative studies of the emission predicted by the polar cap, the outer gap and the two-pole caustics models. In this work, we study the…
The linear polarisation fraction and angle of the hard X-ray emission from the Crab provide unique insight into high energy radiation mechanisms, complementing the usual imaging, timing and spectroscopic approaches. Results have recently…
Polarimetric observations of celestial sources in the hard X-ray band stand to provide new information on emission mechanisms and source geometries. PoGO+ is a Compton scattering polarimeter (20-150 keV) optimised for the observation of the…
The Crab nebula and its pulsar have been observed for about 3 hours with the high-speed photo-polarimeter OPTIMA in January 2002 at the Calar Alto 3.5m telescope. The Crab pulsar intensity and polarization are determined at all phases of…
The linear polarisation of the Crab pulsar and its close environment was derived from observations with the high-speed photo-polarimeter OPTIMA at the 2.56-m Nordic Optical Telescope in the optical spectral range (400 - 750 nm). Time…
Polarization is a powerful diagnostic tool to constrain the site of the high-energy pulsed emission and particle acceleration in gamma-ray pulsars. Recent particle-in-cell simulations of pulsar magnetosphere suggest that high-energy…
In this paper we first provide a brief history of the handful of X-ray polarization measurements that have been accomplished to date. We then outline new technological developments that indicate more detailed polarization measurements in…
We present the results from the Hitomi Soft Gamma-ray Detector (SGD) observation of the Crab nebula. The main part of SGD is a Compton camera, which in addition to being a spectrometer, is capable of measuring polarization of gamma-ray…