A self consistent model of galaxy formation across cosmic time

A self consistent model of galaxy

formation across cosmic timeBruno Henriques

Simon White, Peter Thomas

Raul Angulo, Qi Guo, Gerard Lemson, Volker Springel

different supernova feedback (increased efficiency)

Merger treatment

The Munich ModelThe Munich Model

Guo et al. 2011

Henriques et al. 2011, 2012

different stellar populations

Croton et al. 2006

De Lucia & Blaizot 2007

AGN feedback model (suppression of cooling)

dust model

SN feedback model - reheating + ejection + reincorporation

Henriques B., White S., Lemson G., Thomas P., Guo Q., Marleau D., Overzier R.,

2012, MNRAS

LightconesLightcones

Extended photometric coverage

Multiple Stellar Populations

Pencil Beams + All Sky

http://www.mpa-garching.mpg.de

B-band Luminosity FunctionB-band Luminosity Function

Stellar Mass FunctionStellar Mass Function

K-band Luminosity FunctionK-band Luminosity Function

Semi-analytic modelling

MCMC

Complex galaxy

formation physics

Choose parameters to sampleStar formation, SN feedback, AGN feedback efficiency, Metals yield

Choose observational constraintsStellar Mass Function, K-band & B-band Luminosity Functions

MCMC Parameter SamplingMCMC Parameter SamplingHenriques B., Thomas P., Oliver S., Roseboom I., MNRAS, 2009

Henriques B., Thomas P., MNRAS, 2010

Constrain the model at multiple redshifts

Large Volume

Across Cosmic Time

Time varying parametersTime varying parametersA clear & unique change was revealed by the pre-

processing stepReincorporation of gas after ejection by SN feedback ( high-z low-z )All other parameters have consistent regions at all z

Any other parametrisation with time is ruled out, for example, in our model, a change in star formation efficiency is ruled

out.

New parametrizationNew parametrization

Reincorporation time scaling with Mvir, due to the slow down of outgoing material caused by

dynamical friction.

Single SetSingle SetStrong ejection + no reincorporation set the low mass end at high-z

Strong reincorporation at later times produces the required build up for z<1

ResultsResults

Colors and SFRColors and SFR

The delayed reincorporation of

gas shifts star formation towards

lower redshift.

Dwarfs are bluer, have higher star formation

rates and younger ages.

ClusteringClustering

Dwarf galaxies form later, in higher mass halos that are less

cluster.

Galaxy formation physics, and not just cosmology, have a strong impact on galaxy clusterin.

ConclusionsConclusions

Extend the MCMC sampling to multiple redshifts for a wide range of observations, taking full advantage of the self-consistent evolution of galaxies

Pre-processing step that shows Guo11 parametrization to be nearly optimal at z=0. Reincorporation change required by the evolution of galaxy properties.

Simple adjustment to the model allows us to get a reasonable fit at all redshifts for the masses, K-band and B-band luminosities.

There is no longer an excess of dwarfs at high redshift

Evolution of the massive end is reproduced across cosmic time

Extended MCMC CapabilitiesExtended MCMC Capabilities

Observational constraints at multiple redshifts

Time-evolution of parameters (pre-processing step)

Stellar mass and luminosity functions constraints from z=3 to z=0 Takes full advantage of the self-consistent evolution of galaxies

If not needed, the current parametrisation is not ruled out by observationsIf needed, a different parametrisation is required (it rules out any others)

If a good fit can not be found, the current model is ruled out

M05 vs BC03

Gas

TB-AGB

TB-AGB + RHeB