The Circum gaLactic mEdium around gAlaxies: when baRyons iNvESt haloS

22-26 June 2020, IAP, Paris

The circum-galactic medium (CGM) surrounding galaxies is the interface between gas accreting from the cosmic web and outflows driven by massive stars and active galactic nuclei (AGN) in galaxies. It is the processes that occur as baryons flow into and out of the CGM that undoubtedly regulates galaxy formation and evolution. The CGM, and by extension to the most massive halos, the inter-cluster medium, are significant reservoirs of gas, metals, and dust, likely as significant as the total baryon content within galaxies. Over the last 3 decades, observers have identified 3 significant problems in the physical characteristics of galaxies which are still largely with us at present. These mysteries are:

This 36th IAP colloquium will set the baseline for our understanding of the CGM at the dawn of the JWST era. Moreover, as the CGM will be an important component in justifying future facilities such as Athena, such a meeting will provide directions for the capabilities of these missions. We are now at a cross-roads: as more and more data are taken and simulations are becoming more sophisticated, it is time to take stock of what we know and how we can make progress in answering the above questions raised by our new understanding of the CGM.


You can contact us at:


  • Matthew Lehnert (chair)
  • Pierre Guillard (co-chair)
  • Megan Donahue
  • Jessica Werk
  • Hsiao-Wen Chen
  • Sebastiano Cantalupo
  • Arif Babul
  • Michael McDonald


  • Pierre Guillard (chair)
  • Valeria Olivares
  • Fiorella Polles
  • Lukas Furtak
  • Amael Ellien
  • Jens-Kristian Krogager
  • Pasquier Noterdaeme
  • Sandy Artero
  • Valérie Bona

Code of conduct

We are committed to making this conference productive and enjoyable for everyone, regardless of gender, sexual orientation, disability, physical appearance, race, nationality, or religion. Discrimination or harassment of participants in any form will not be tolerated.

Important dates

January 2020, 31st :
Early registration is open
March 31st 2020:
Early-registration closes
April 15th 2020:
End of abstract submission
June 15th 2020:
Registration closes