INVESTIGADORES
RAGONE FIGUEROA Cinthia Judiht
congresos y reuniones científicas
Título:
BCGs in Cosmological Numerical Simulations
Autor/es:
RAGONE FIGUEROA, CINTHIA; GRANATO, GIAN LUIGI; MURANTE, GIUSEPPE; BORGANI, STEFANO
Lugar:
Trieste
Reunión:
Workshop; 4th HydroSim Meeting; 2013
Institución organizadora:
ISTITUTO NAZIONALE DI ASTROFISICA - TRIESTE - ITALIA
Resumen:
We analyse the basic properties of brightest cluster galaxies (BCGs) produced by state of the
art cosmological zoom-in hydrodynamical simulations. These simulations have been run with
different subgrid physics included. Here we focus on the results obtained with and without the
inclusion of the prescriptions for supermassive black hole growth and of the ensuing active
galactic nuclei (AGN) feedback. The latter process goes in the right direction of decreasing
significantly the overall formation of stars. However, BCGs end up still containing too much
stellar mass, a problem that increases with halo mass, and having an unsatisfactory structure.
This is in the sense that their effective radii are too large, and that their density profiles feature
a flattening on scales much larger than observed. We also find that our model of thermal AGN
feedback has very little effect on the stellar velocity dispersions, which turn out to be very
large. Taken together, these problems, which to some extent can be recognized also in other
numerical studies typically dealing with smaller halo masses, indicate that on one hand present
day subresolution models of AGN feedback are not effective enough in diminishing the global
formation of stars in the most massive galaxies, but on the other hand they are relatively too
effective in their centres. It is likely that a form of feedback generating large-scale gas outflows
from BCGs precursors, and a more widespread effect over the galaxy volume, can alleviate
these difficulties.