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Published on: September 6, 2012
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Polarized x-rays from a magnetar
Roberto Taverna1, Roberto Turolla1,2, Fabio Muleri3
1Department of Physics and Astronomy, University of Padova, I-35131 Padova, Italy.
Science (New York, N.Y.)
|November 10, 2022
Summary
Polarized X-ray observations reveal magnetar 4U 0142+61 has a complex magnetic field. Polarization varies with energy, suggesting radiation scattering in the magnetar’s magnetosphere.
Area of Science:
- Astrophysics
- High-energy astrophysics
- Neutron star research
Background:
- Magnetars are neutron stars characterized by extremely powerful magnetic fields.
- X-ray observations are crucial for studying magnetar properties.
- Polarization measurements offer insights into magnetic fields and surface characteristics.
Purpose of the Study:
- To investigate the polarization of X-rays emitted by the magnetar 4U 0142+61.
- To determine the degree and energy dependence of X-ray polarization from this magnetar.
- To test models of magnetar emission mechanisms.
Main Methods:
- Utilized the Imaging X-ray Polarimetry Explorer (IXPE) for observations.
- Measured the linear polarization degree and angle of X-rays from 4U 0142+61.
- Analyzed polarization across the 2- to 8-kilo-electron volt energy band.
Main Results:
- Detected a significant linear polarization degree of 13.5 ± 0.8% averaged over 2-8 keV.
- Observed energy-dependent polarization: 15.0 ± 1.0% (2-4 keV), low polarization (~4-5 keV), and 35.2 ± 7.1% (5.5-8 keV).
- Recorded a 90° polarization angle shift around 4-5 keV.
Conclusions:
- The observed polarization properties are consistent with thermal surface radiation.
- Scattering of charged particles within the magnetar's magnetosphere likely reprocesses the radiation.
- These findings support models involving magnetospheric particle interactions in magnetar emission.
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