Bir pulsarın eş yıldızının rüzgârını yakalayışını izlemek

The XRISM X-ray observatory has provided the clearest direct evidence yet of plasma from a giant star falling onto its compact companion. The system, BP Crucis, lies about 13,000 light-years away and contains a blue hypergiant and a much smaller neutron star that acts as a pulsar. During parts of its 41.5-day orbit, the pulsar crosses a dense stream within the larger star’s wind, captures gas and produces powerful X-ray flares. XRISM observed the system for about 16 hours near the end of one such flare. Its high-resolution spectrometer detected redshifted absorption lines from highly ionised iron. These shifts showed that plasma was moving towards the pulsar at roughly 540,000 kilometres per hour. Researchers think the gas first forms a turbulent disc, then falls directly onto the neutron star when the flow lacks enough angular momentum to keep that disc intact. The observations offer a new test of models for wind-fed pulsars.