Jan-Willem den Herder has been over 30 years involved in high-energy missions. He took part in the realization of the Reflection Grating Spectrometer (RGS) on XMM-Newton which is now operational for 20 years. The next logical step was to realize the similar quality of the spectra but now for spatially extended sources.
The main scientific interest of Jan-Willem is to detect the very weak emission in the cosmic web which can be found in the filaments between clusters. Whereas current instrumentation is able to identify this gas under the most favourable conditions, a proper mapping requires a much more sensitive instrument such as the X-IFU on Athena.
Jan-Willem is leading the SRON group which has pioneered the cryogenic X-ray calorimeters in Europe and he is co-PI of the X-IFU instrument. After many years, the Athena mission is now becoming a reality and he will be really happy when the results will be obtained by the next generation of scientists.
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Image: A slice of a simulation of the Evolution and Assembly of Galaxies and Their Environments (EAGLE) project. Hot gas reaches temperatures of more than 100,000K that can be observed using X-ray observatories. The insets zoom into a galaxy like the Milky Way. Credit: The EAGLE Project: Simulating the Evolution and Assembly of Galaxies and Their Environments,” Schaye et al., January 2015, Monthly Notices of the Royal Astronomical Society, Vol. 446, 521-554.