%0 Generic %1 Jaacks2011 %A Jaacks, Jason %A Choi, Jun-Hwan %A Nagamine, Kentaro %D 2011 %K lumfunc reionization simulation %T Steep Faint-end Slopes of Galaxy Mass and Luminosity Functions at z >=6 in Cosmological SPH Simulations %U http://arxiv.org/abs/1104.2345 %X We present the results of a numerical study comparing photometric and physical properties of simulated z=6-9 galaxies to the observations taken by the WFC3 instrument aboard the Hubble Space Telescope. Using cosmological hydrodynamical simulations we find good agreement with observations in color-color space at all studied redshifts. We also find good agreement between observations and our Schechter luminosity function fit in the observable range, M_uv <= -18. However beyond what currently can be observed, simulations predict a very large number of low-mass galaxies and evolving steep faint-end slopes from \alpha_L = -2.15 at z=6 to \alpha_L = -2.64 at z=9, with a dependence of |\alpha_L| (1+z)^0.59. During the same epoch, the normalization \phi^* increases and the characteristic magnitude M_uv becomes moderately brighter with decreasing redshift. We find similar trends for galaxy stellar mass function with evolving low-mass end slope from \alpha_M =-2.26 at z=6 to \alpha_M =-2.87 at z=9, with a dependence of |\alpha_M| (1+z)^0.65. Together with our recent result on the high escape fraction of ionizing photons for low-mass galaxies, our results suggest that the low-mass galaxies are important contributor of ionizing photons for the reionization of the Universe at z >=6.

@misc{Jaacks2011, abstract = { We present the results of a numerical study comparing photometric and physical properties of simulated z=6-9 galaxies to the observations taken by the WFC3 instrument aboard the Hubble Space Telescope. Using cosmological hydrodynamical simulations we find good agreement with observations in color-color space at all studied redshifts. We also find good agreement between observations and our Schechter luminosity function fit in the observable range, M_uv <= -18. However beyond what currently can be observed, simulations predict a very large number of low-mass galaxies and evolving steep faint-end slopes from \alpha_L = -2.15 at z=6 to \alpha_L = -2.64 at z=9, with a dependence of |\alpha_L| \propto (1+z)^0.59. During the same epoch, the normalization \phi^* increases and the characteristic magnitude M_uv becomes moderately brighter with decreasing redshift. We find similar trends for galaxy stellar mass function with evolving low-mass end slope from \alpha_M =-2.26 at z=6 to \alpha_M =-2.87 at z=9, with a dependence of |\alpha_M| \propto (1+z)^0.65. Together with our recent result on the high escape fraction of ionizing photons for low-mass galaxies, our results suggest that the low-mass galaxies are important contributor of ionizing photons for the reionization of the Universe at z >=6. }, added-at = {2011-04-14T09:44:36.000+0200}, author = {Jaacks, Jason and Choi, Jun-Hwan and Nagamine, Kentaro}, biburl = {https://www.bibsonomy.org/bibtex/23278686f5c92dee12e68dc6875c15c2d/miki}, description = {[1104.2345] Steep Faint-end Slopes of Galaxy Mass and Luminosity Functions at z >=6 in Cosmological SPH Simulations}, interhash = {c325d553c75de328b3fd690ab82f064b}, intrahash = {3278686f5c92dee12e68dc6875c15c2d}, keywords = {lumfunc reionization simulation}, note = {cite arxiv:1104.2345 Comment: 14 pages, 5 tables, 12 figures. Submitted}, timestamp = {2011-04-14T09:44:36.000+0200}, title = {Steep Faint-end Slopes of Galaxy Mass and Luminosity Functions at z >=6 in Cosmological SPH Simulations}, url = {http://arxiv.org/abs/1104.2345}, year = 2011 }