Athena X-ray Advances: ASST & ACO Science Webinars

The next webinar of the “Athena X-ray Advances: ASST & ACO Science Webinars” will take place on the 28th of September at 15 CEST. Dominique Eckert will give the webinar entitled: Probing the nature of dark matter with X-ray observations of massive galaxy clusters.

Abstract: In spite of its numerous successes, the LambdaCDM model of cosmology is fundamentally incomplete, in the sense that 95% of the postulated matter-energy content is in an unknown form. Specifically, the LambdaCDM model postulates the existence of an unknown matter component, dubbed dark matter, which outweighs all the normal matter content of galaxies by a factor of 5-6. The gravitational effects of dark matter can be studied exquisitely well by observing the dynamics of the most massive structure in today’s Universe - galaxy clusters. In this respect, deep X-ray observations of nearby galaxy clusters play a key role in our understanding of the gravitational field of collapsed halos. Indeed, galaxy clusters are filled with a hot, tenuous plasma - the intracluster medium (ICM) - which contains the vast majority of their baryons and shines predominantly in X-rays. The pressure exerted by the hot gas equilibrates the gravitational force, such that the total enclosed mass can be derived point-by-point from the thermodynamic properties of the ICM. I will review our current knowledge of the gravitational field of galaxy clusters and what can be learned from it on the properties of the postulated dark matter, with an emphasis on several recent studies focusing on the thermodynamic properties of 12 massive, nearby systems. I will show how such observations can be used to constrain the self-interaction cross section of dark matter and how the measured gravitational field sets constraints on modified gravity theories. Finally, I will discuss what can potentially be achieved in this field with the help of a powerful new X-ray observatory like Athena.

The webinar connection details are: https://us06web.zoom.us/j/81337557151?pwd=dGYvTEJOMlJxdThVdFZFdkMzWlF3Zz09

Webinar ID: 813 3755 7151 (Passcode: 135183).

Further information, including the code of conduct, is accessible on the dedicated website.