Sketch of the double star system of Hercules X-1: A donor star transports matter across an accretion disk into the tiny neutron star in the center of the disk. The neutron star is shown magnified in blue in the front. The IXPE data allowed the measurement of the angles between all relevant axes and revealed that, unexpectedly, the axis of rotation is not aligned with the direction of the angular momentum of the binary star orbit.
Sketch of the double star system of Hercules X-1: A donor star transports matter across an accretion disk into the tiny neutron star in the center of the disk. The neutron star is shown magnified in blue in the front. The IXPE data allowed the measurement of the angles between all relevant axes and revealed that, unexpectedly, the axis of rotation is not aligned with the direction of the angular momentum of the binary star orbit. An X-ray pulsar is a rotating magnetized neutron star. The very first direct measurement of the polarization of an X-ray pulsar by the Imaging X-ray Polarimetry Explorer (IXPE) space telescope has challenged previous models of such systems. The degree of polarization of the X-ray pulsar Hercules X-1 was much lower than theoretically predicted, so astrophysicists are now having to reconsider their basic ideas about the geometry and structure of matter flows. According to the new findings, the axis of rotation and the magnetic axis of the neutron star, as well as the direction of angular momentum in this binary star system, are not - as expected - aligned, so that the object wobbles like a spinning top.
TO READ THIS ARTICLE, CREATE YOUR ACCOUNT
And extend your reading, free of charge and with no commitment.
