Speaker
Description
The spectral and timing behaviour of neutron star high-mass X-ray binaries (HMXBs) offers a unique opportunity to investigate accretion onto compact objects and the wind structures of massive stars. In particular, understanding the X-ray emission from neutron stars is a critical topic of research for current and future astrophysical studies. This is a prominent science case of the NewAthena mission and will be discussed in the upcoming NewAthena Special Issue. Recently, XRISM made it possible to resolve, for the first time in an HMXB, the Fe Kα doublet and to obtain precise measurements of wind velocities via Doppler shifts thanks to its microcalorimeter Resolve. These results demonstrated how high-resolution microcalorimeter spectroscopy can transform our view of (i) the wind geometry, (ii) the ionisation structure and chemical composition, and (iii) line-of-sight dynamics. With NewAthena, we will perform time-resolved spectroscopy for the first time on timescales down to hundreds of sec to track rapid absorption changes as the compact object orbits its donor star. In this talk, we will discuss our recent simulations and results in the context of the NewAthena Special Issue with reliable statistical approaches, using state-of-the-art frameworks for X-ray spectral analysis based on Bayesian inference (e.g. jaxspec).
