The role of quasars in the formation of distant galaxies
David Elbaz
CEA
Résumé :
Deep infrared observations of the Universe have revealed
a new vision of the global history of star formation in
the Universe. The picture in which galaxy mergers would
explain the rapid fall of the star formation activity in
the Universe or the origin of the luminous galaxies in the
distant Universe is being questioned by observations both
in the distant and local Universe. If the role of mergers
in galaxy evolution cannot be questionned in itself, other
interpretations must be considered and the role of central
black holes may have been largely underestimated both on
the side of its energetic contribution to the infrared light
and on the side of its physical impact on star formation
in galaxies. Are the histories of star formation and
accretion by black holes parallel or delayed with respect
to one another ? Who came first ? Did stars and black holes
co-evolve in galaxies or is there a direct impact of one onto
the other ? Is it negative or positive feedback ? Those questions
have been addressed by various observational angles and
theoretical considerations during the recent years.
We will propose a perspective based on deep far infrared
observations together with a discussion of a local system
that may provide a prototypical example of how galaxy formation
might be strongly affected by quasar activity.
