RSAA Colloquia / Seminars / Feast-of-Facts: Friday, 22 February 2019, 14:00-14:20; CSO Common Room

Matthew Baring

"Discerning the Magnetic Inclination of Spinning Magnetars"

Magnetars are young neutron stars with high surface magnetic fields, exceeding around 10 TeraGauss. Pulsed non-thermal quiescent X-ray emission extending between 10 keV to >150 keV has been observed in about 10 magnetars by RXTE, INTEGRAL, Suzaku, NuSTAR and Fermi-GBM. This talk briefly describes a model for such hard X-ray signals, wherein the emission is produced by resonant Compton upscattering of soft thermal photons from the neutron star surface. Key pulsation and spectral signatures can be used to constrain the viewing geometry and the angle between the magnetic and spin axes of magnetars. Polarization probes by future Compton telescopes may enable the discernement of whether or not attenuation by magnetic photon splitting is active.