Camille Diez - Personal Profiles

Main Research Fields

I am an observational astrophysicist studying accreting neutron stars in binary systems and their local environment. X-ray binaries are made up of a normal star (called companion star) and a collapsed star (also called compact object). The latter can be a neutron star, a black hole or a white dwarf. My research focuses on neutron stars in X-ray binaries as they are one of the most fascinating objects in the Universe due to extreme accretion physics and still unknown internal structure. Albeit several theoretical models exist to describe the local accretion structure and predict the equation of state of dense matter in neutron stars, observational studies are still lacking to confirm these theories or at least narrow the range of possibilities.

I look at the strong X-ray radiation from accreting neutron stars to assess the physical structure of the material accreted by the neutron star and originating from the stellar wind of the companion star. High-resolution spectroscopy provides an in-depth view of the conditions of the stellar wind (geometry, composition, ...) and therefore of the neutron star's vicinity. I have expertise with NuSTAR, XMM-Newton and I am also interested in the upcoming XRISM and Athena (2030+) X-ray missions for their unprecedented spectral and spatial resolutions which will be crucial for this kind of study. Using optical instruments at the VLT, I also perform radial velocity measurements by measuring Doppler shifts of observed emission lines in X-ray binaries to constrain the mass of neutron stars and therefore further the effort to describe their interior.