8–13 Sept 2019
Europe/Rome timezone
All inquiries about receipts for the payment of the conference fee and/or dinner should be addressed to: a.vriz@fondazionealmamater.it, d.bordignon@fondazionealmamater.it

Exploring the Virialization Region of Merging Galaxy Clusters

10 Sept 2019, 15:20
15m

Speaker

Dr Scott Randall (Harvard-Smithsonian Center for Astrophysics)

Description

X-ray observations of the outskirts of galaxy clusters show that the entropy of the intracluster medium (ICM) in the virialization region is generally less than what is expected based on purely gravitational structure formation. Possible explanations include electron/ion non-equilibrium, accretion shocks that weaken during cluster formation, and the presence of unresolved cool gas clumps. These mechanisms are expected to correlate with large scale structure (LSS), such that the entropy is lower in regions where the ICM interfaces with LSS filaments and, presumably, the warm-hot intergalactic medium (WHIM). Major, binary cluster mergers are expected to take place at the intersection of LSS filaments, with the merger axis initially oriented along a filament. We present results from deep X-ray observations of the virialization regions of binary, early-stage merging clusters, including a possible direct detection of the dense end of the WHIM along a LSS filament.

Affiliation Harvard-Smithsonian Center for Astrophysics
Topic Hot and diffuse baryons

Primary author

Dr Scott Randall (Harvard-Smithsonian Center for Astrophysics)

Co-authors

Presentation materials