Victor Doroshenko

astrophysicist@IAAT

Sep 01, 2022

Angling for x-ray pulsar geometry with polarimetry

And now my share of the X-ray polarization pie. A very important source for me (did my Bachelor on it!) and for the IAAT: Her X-1. In the latest Nature Astronomy paper we use phase-resolved X-ray polarimetry to constrain the geometry of the pulsar.

her x-1 phase-resolved polarimetry

We also add old optical polarimetry to the mix to show that the spin axis of the neutron star is misaligned with its orbital axis - a condition required to allow its free precession (suggested previously to explain observed changes of the pulse profile shape over the 35d super-orbital variability cycles). More observations are coming next year, and of course more observations of X-ray pulsars by IXPE too! The paper attracted quite a bit of attention, so we also have a press-release from the University and NASA