Galaxy formation with cold gas accretion and evolving stellar initial mass function

Abstract

The evolution of the galaxy stellar mass function is especially useful to test the current model of galaxy formation. Observational data have revealed a few inconsistencies with predictions from the $\Lambda \mathrm{CDM}$ model. For example, most massive galaxies have already been observed at very high redshifts, and they have experienced only mild evolution since then. In conflict with this, semi-analytical models of galaxy formation predict an insufficient number of massive galaxies at high redshift and a rapid evolution between redshift 1 and 0 . In addition, there is a strong correlation between star formation rate and stellar mass for star-forming galaxies, which can be roughly reproduced with the model, but with a normalization that is too low at high redshift. Furthermore, the stellar mass density obtained from the integral of the cosmic star formation history is higher than the measured one by a factor of 2. In this paper, we study these issues using a semi-analytical model that includes: 1) cold gas accretion in massive halos at high redshift; 2) tidal stripping of stellar mass from satellite galaxies; and 3) an evolving stellar initial mass function (bottom-light) with a higher gas recycle fraction. Our results show that the combined effects from 1) and 2) can predict sufficiently massive galaxies at high redshifts and reproduce their mild evolution at low redshift, While the combined effects of 1) and 3) can reproduce the correlation between star formation rate and stellar mass for star-forming galaxies across wide range of redshifts. A bottom-light/top-heavy stellar IMF could partly resolve the conflict between the stellar mass density and cosmic star formation history.

9 pages, 7 figures. Accepted for publication in ApJ

References in corpus (21)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
• Cold streams in early massive hot haloes as the main mode of galaxy formation
• The hierarchical formation of the brightest cluster galaxies
• A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei
• UV Luminosity Functions at z~4, 5, and 6 from the HUDF and other Deep HST ACS Fields: Evolution and Star Formation History
• A primer on hierarchical galaxy formation: the semi-analytical approach
• The Galaxy Mass Function up to z=4 in the GOODS-MUSIC sample: into the epoch of formation of massive galaxies
• Bimodal gas accretion in the Horizon-MareNostrum galaxy formation simulation
• The high redshift galaxy population in hierarchical galaxy formation models
• The Millennium Galaxy Catalogue: the B-band attenuation of bulge and disc light and the implied cosmic dust and stellar mass densities
• The Hierarchical Build-Up of Massive Galaxies and the Intracluster Light since z=1
• The Evolution of Stellar Mass and the Implied Star Formation History
• The evolution of the near-IR galaxy Luminosity Function and colour bimodality up to z ~ 2 from the UKIDSS Ultra Deep Survey Early Data Release
• The dependence of Star Formation on Galaxy Stellar Mass
• The star-formation history of K-selected galaxies
• The contribution of star formation and merging to stellar mass buildup in galaxies
• Diffuse stellar component in galaxy clusters and the evolution of the most massive galaxies at z<~1
• On the Constancy of the Characteristic Mass of Young Stars
• Accretion, feedback and galaxy bimodality: a comparison of the GalICS semi-analytic model and cosmological SPH simulations
• Constraints on the star formation histories of galaxies from z~1 to z~0

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• Introducing the Illustris Project: the evolution of galaxy populations across cosmic time
• Bayesian inference of galaxy formation from the K-band luminosity function of galaxies: tensions between theory and observation
• The specific star formation rate of high redshift galaxies: the case for two modes of star formation
• Cosmological Implications of a Stellar Initial Mass Function that Varies with the Jeans Mass in Galaxies
• On the cosmic evolution of the specific star formation rate
• On the algorithms of radiative cooling in semi-analytic models
• Variations of the Initial Mass Function in Semi-Analytical models
• Resolving the problem of galaxy clustering on small scales: any new physics needed?
• The stellar mass function and efficiency of galaxy formation with a varying initial mass function
• Constraints on the Evolution of the Galaxy Stellar Mass Function II: Quenching Timescale of Galaxies and its Implication for their Star Formation Rate
• Extending PLE models into the mid-IR, far-IR & sub-mm
• Constraining galactic baryon cycle using the galaxy stellar-to-halo mass relations