Galaxy formation in the Planck cosmology – I. Matching the observed evolution of star formation rates, colours and stellar masses

Abstract

We have updated the Munich galaxy formation model to the Planck first-year cosmology, while modifying the treatment of baryonic processes to reproduce recent data on the abundance and passive fractions of galaxies from z = 3 down to z = 0. Matching these more extensive and more precise observational results requires us to delay the reincorporation of wind ejecta, to lower the surface density threshold for turning cold gas into stars, to eliminate ram-pressure stripping in haloes less massive than ∼ 10 14 M ⊙ , and to modify our model for radio mode feedback. These changes cure the most obvious failings of our previous models, namely the overly early formation of low-mass galaxies and the overly large fraction of them that are passive at late times. The new model is calibrated to reproduce the observed evolution both of the stellar mass function and of the distribution of star formation rate at each stellar mass. Massive galaxies (log M * / M ⊙ 11.0) assemble most of their mass before z = 1 and are predominantly old and passive at z = 0, while lower mass galaxies assemble later and, for log M * / M ⊙ 9.5, are still predominantly blue and star forming at z = 0. This phenomenological but physically based model allows the observations to be interpreted in terms of the efficiency of the various processes that control the formation and evolution of galaxies as a function of their stellar mass, gas content, environment and time.

The structure and evolution of a forming galaxy cluster atz= 1.62

“…We construct a sample of simulated galaxy protoclusters that have similar structural properties to Cl 0218.3−0510 using the Henriques et al (2015) semi-analytic model applied to the Millennium Simulation (Springel et al 2005) scaled to the Planck Cosmology (Planck Collaboration XVI 2014). The simulated box is periodic of side length 480 Mpc h −1 where h = 0.673.…”

“…Therefore not all galaxies that have similar redshifts as the main halo will fall into the cluster, and some of the 'protocluster galaxies' selected in Section 2.2.3 will not be true cluster progenitors. We use the Planck-scaled Millennium Simulation with the semi-analytic model of Henriques et al (2015) to determine which of Cl 0218.3−0510's galaxies will become cluster members by Probability of becoming a cluster member All galaxies in FoV Intergroup galaxies Group galaxies Figure 11. The probability of galaxies within Cl 0218.3−0510-like protoclusters in the Millennium Simulation becoming cluster members by z = 0. z = 0.…”

Redshift evolution of stellar mass versus gas fraction relation in 0 <z< 2 regime: observational constraint for galaxy formation models

“…The inflow rate into a galaxyṀin is expressed as 6 Recent studies on galaxy formation based on the semi-analytic approach have suggested that the f H 2 gap between the observations and theoretical predictions decreases if the timescales for re-accretion of the ejected gas have a mass-and time-dependence (Henriques et al 2013(Henriques et al , 2015Mitchell et al 2014;White et al 2015). Even though the physical origin for this treatment is not clear, some feedback processes may be attributed to changing the re-accretion timescale.Ṁ in =Ṁgrav −Ṁprev +Ṁrecyc,…”

The impact of galactic properties and environment on the quenching of central and satellite galaxies: a comparison between SDSS, Illustris and L-Galaxies

“…Observationally, satellites in general depend on both intrinsic and environmental parameters for their quenching, whereas centrals depend primarily only on intrinsic properties (e.g., Peng et al 2012). In many simulations and models, the quenching of central galaxies is governed primarily by AGN feedback and the quenching of satellite galaxies is governed primarily by environmental processes, such as, e.g., strangulation or stripping (e.g., Guo et al 2011;Vogelsberger et al 2014a,b;Henriques et al 2015;Schaye et al 2015;Peng et al 2015;Somerville et al 2015).…”

“…Since the idea that most galaxies contain a supermassive black hole was first suggested (e.g., Kormendy & Richstone 1995), the energy released from forming these objects has become a popular mechanism for regulating gas flows and star formation in simulations, particularly for massive galaxies (e.g., Croton et al 2006; Bower et al 2006Bower et al , 2008Somerville et al 2008; Guo et al 2011;Vogelsberger et al 2014a,b;Henriques et al 2015; Schaye et al 2015). In fact, substantial feedback from accretion around supermassive black holes is required in cosmological semi-analytic models, semi-empirical models, and hydrodynamical simulations to achieve the steep slope of the high-mass end of the galaxy stellar mass function (e.g., Vogelsberger et al 2014a,b;Henriques et al 2015;Schaye et al 2015).…”