SEMPARIS – Séminaires en région parisienne Colloquium du

SEMPARIS – Séminaires en région parisienne
http ://string.lpthe.jussieu.fr/semparis/
Colloquium du Département de Physique
de l’ENS
Jeudi 18 Juin 2015, 13 :30
DPT-PHYS-ENS, Amphitheatre Darboux, Institut Henri Poincare, Paris
Domaines : astro-ph
Titre : Super-massive black holes reject their food
Orateur : Francoise Combes ( Observatoire de Paris )
Résumé : Every galaxy hosts in its center a super-massive black hole (SMBH)
of mass between one million and a few billion solar mass. Since the masses of
black holes and galaxy bulges are proportional, it is likely that star formation
and SMBH feeding occurs simultaneously and that both bulges and SMBH
grow in symbiosis.
Massive molecular outflows have been recently discovered, in galaxies either
actively forming stars or not, but in general showing signs of nuclear activity
(AGN). Contrary to previous outflows detected in ionised gas, they contain
a large fraction of the gas mass, and are able to impact significantly the evolution of the host galaxy, by regulating or stopping the amount of cold gas
available for nuclear star formation, or black hole accretion. Is this evidence
of the strong AGN feedback, invoked by galaxy formation models to explain
the baryons to dark matter ratios ? or can this regulate the symbiotic bulge
and SMBH growth ? The current observations will be reviewed and compared
to models.