A multi-wavelength view of the isolated neutron star eRASSU J065715.3+260428

Vol. 694
7. Stellar structure and evolution

A multi-wavelength view of the isolated neutron star eRASSU J065715.3+260428

The Galactic sample of known isolated neutron stars is extremely small, so any new member of the class is important for understanding their evolution. However, most have similar high-energy properties, whether it is their gamma-ray luminosities or thermal X-rays. This study presents a multiwavelength campaign on one such source discovered in the eROSITA survey that breaks the mold. The source, J0657, is an X-ray pulsar with a roughly 0.25 sec period, but it is significantly not detected in every other energy interval from radio to gamma rays. The authors derived a spindown rate and they draw a comparison with other rotation-powered radio pulsars, highlighting the unusual properties of the source. The X-ray emission is best fit by a two-temperature thermal spectral energy distribution, but with an absorption feature that the authors investigated as a possible proton or electron cyclotron line.