Context. The discovery of fast and variable coherent signals in a handful of ultraluminous X-ray sources (ULXs) points to the presence of super-Eddington accreting neutron stars, …
Ultraluminous X-ray sources (ULX) are extragalactic objects with observed X-ray luminosities largely above the Eddington limit for a 10 M⊙ black hole. Currently, it is believed …
The discovery of several ultraluminous X-ray sources exhibiting fast and rapidly evolving X-ray pulsations unequivocally associates these sources with accreting neutron stars …