The Chemical Enrichment of the Intergalactic Medium


May 25 - 29, 2009


From May 25 through May 29, 2009, 65 people from 11 countries

participated in what turned out to be a very successful meeting at the

Lorentz Center.


The chemical enrichment of the intergalactic medium (IGM), which

contains most of the baryons in the universe, provides us with a

fossil record of past star formation and a unique laboratory to study

physical processes that are crucial for our understanding of galaxy

formation and evolution. The pollution of the IGM with metals also has

profound consequences for the formation of stars and galaxies through

its effect on the radiative cooling rates.


Although substantial progress has been made in recent years, the

enrichment of the IGM remains poorly understood. The distribution and

relative abundances of intergalactic metals are still uncertain and it

is unclear what the dominant enrichment mechanism is and how it varies

with redshift and environment. Much observational and theoretical work

remains to be done to fully exploit the potential of intergalactic

metals as a tool to constrain models of galaxy formation and



The workshop "The chemical enrichment of the intergalactic medium"

brought together researchers working on models and observations, on

the intracluster/group medium and the diffuse IGM, on the low- and

high-redshift IGM, and on galactic winds. There was a healthy balance

between senior researchers, postdocs and PhD students.


The program consisted of 9 invited reviews, 9 invited targeted talks,

23 contributed talks, 9 plenary discussions, 18 posters, and ample

time for for people to work in small groups in their offices or in the

one of the meeting rooms. There were two workshop dinners, one as part

of a boat tour and one on the beach in Katwijk, as well as a wine &

cheese party.


The workshop was successful in all respects. People were brought up to

date, existing collaborations were expanded and new ones were

formed. The mix of different backgrounds turned out to be very

productive as it enabled the participants to get to know different

communities working on related aspects of the same problems. The large

amount of time scheduled for ``self-organized work'' was very much

appreciated. It allowed people to sit down together for in depth

discussions and brain storms. It also made it possible for

collaborators who work at different institutes to work together and

for new people to get involved.


The diverse and excellent facilities of the Lorentz Center, as well as

the efficient and friendly help from Auke Planjer and Martje Kruk,

greatly contributed to the success of this workshop. The workshop also

marked the end of a 4-year EU Marie Curie Excellence Grant that hosted

a team of researchers working on the topic of the meeting at Leiden

Observatory. A large part of the cost was funded through this grant,

while the remainder was generously covered by the Lorentz Center.


Joop Schaye (Leiden University, The Netherlands)

Stefano Borgani (University of Trieste, Italy)

Xavier Prochaska (UC Santa Cruz, USA)

Micheal Shull (University of Colorado, USA)

Charles Steidel (Caltech, USA)