Research Interests

Stellar winds in HMXBs

A High-Mass X-ray Binary (HMXB) is a binary star system consisting of a massive star (>10M⊙, usually O/B star) dominating the emission of optical light and a X-ray emitting compact object being a neutron star or a black hole. In those systems, the massive star looses large amounts of its mass via radiation-driven mass loss or ”stellar wind” (see Fig. 1). Some of the wind is captured by the compact object. As it is accreted onto the compact object, it produces X-rays. HMXBs are building blocks of star clusters and galaxies as they significantly influence the surrounding medium via gas outflow and ionising radiation. At the end of their life, massive stars will explode as supernovae or gamma ray bursts and enrich the interstellar medium with heavy elements.

Fig. 1: Simulation of the accreting neutron star in the Vela X-1 HMXB. The colour gradient accounts for varying density.
Credits: John M. Blondin.

Fig. 2: Artist's view of XRISM.
Credits: JAXA.

My research focuses on studying the strong X-ray radiation from accreting neutron stars in HMXBs to assess the physical structure of the material originating from the stellar wind of their massive companion. In particular, high-resolution spectroscopy provides an in-depth view of the physical conditions of the stellar wind. I have expertise with NuSTAR, XMM-Newton and I am an approved postdoctoral researcher involved in the science team for the XRISM Performance Verification phase. I am also interested in the Athena (2030+) X-ray mission for its unprecedented spectral and spatial resolutions which will be crucial for this kind of study.