000162225 001__ 162225
000162225 005__ 20180317093353.0
000162225 0247_ $$2doi$$a10.1111/j.1365-2966.2009.15500.x
000162225 022__ $$a0035-8711
000162225 037__ $$aARTICLE
000162225 245__ $$aCompactness of cold gas in high-redshift galaxies
000162225 269__ $$a2009
000162225 260__ $$bWiley-Blackwell$$c2009
000162225 336__ $$aJournal Articles
000162225 520__ $$aGalaxies in the early Universe were more compact and contained more molecular gas than today. In this paper, we revisit the relation between these empirical findings, and we quantitatively predict the cosmic evolution of the surface densities of atomic (HI) and molecular (H2) hydrogen in regular galaxies. Our method uses a pressure-based model for the H2/HI ratio of the interstellar medium, applied to 3x10^7 virtual galaxies in the Millennium Simulation. We predict that, on average, the HI-surface density of these galaxies saturates at Sigma(HI)<10Msun/pc^2 at all redshifts (z), while H2-surface densities Sigma(H2) evolve dramatically as (1+z)^2.4. This scaling is dominated by a (1+z)^2 surface brightness scaling originating from the. (1+z)^-1 size scaling of galaxies at high z. Current measurements of Sigma(H2) at high z, derived from CO observations, tend to have even higher values, which can be quantitatively explained by a selection bias towards merging systems. However, despite the consistency between our high-z predictions and the sparse empirical data, we emphasize that the empirical data potentially suffer from serious selection biases and that the semi-analytic models remain in many regards uncertain. As a case study, we investigate the cosmic evolution of simulated galaxies, which resemble the Milky Way at z=0. We explicitly predict their HI and H2 distribution at z=1.5, corresponding to the CO-detected galaxy BzK-21000, and at z=3, corresponding to the primary science goal of the Atacama Large Millimeter/submillimeter Array (ALMA).
000162225 6531_ $$aISM: atoms
000162225 6531_ $$aISM: clouds
000162225 6531_ $$aISM: molecules
000162225 6531_ $$agalaxies: evolution
000162225 6531_ $$agalaxies: high-redshift
000162225 6531_ $$aH-2/H I Ratio
000162225 6531_ $$aStar-Formation
000162225 6531_ $$aSubmillimeter Galaxies
000162225 6531_ $$aNeutral Hydrogen
000162225 6531_ $$aNearby Galaxies
000162225 6531_ $$aSpiral Galaxies
000162225 6531_ $$aSize Evolution
000162225 6531_ $$aLine Emission
000162225 6531_ $$aDisk Galaxies
000162225 6531_ $$aMolecular Gas
000162225 700__ $$aObreschkow, D.
000162225 700__ $$aRawlings, S.
000162225 773__ $$j400$$q665-669$$tMonthly Notices Of The Royal Astronomical Society
000162225 8564_ $$s246068$$uhttps://infoscience.epfl.ch/record/162225/files/obreschkow_paper4.pdf$$zn/a
000162225 909CO $$ooai:infoscience.tind.io:162225$$particle$$pSTI
000162225 909C0 $$0252446$$pIGM$$xU10306
000162225 917Z8 $$x130271
000162225 917Z8 $$x130271
000162225 917Z8 $$x130271
000162225 917Z8 $$x130271
000162225 917Z8 $$x148230
000162225 937__ $$aEPFL-ARTICLE-162225
000162225 973__ $$aOTHER$$rREVIEWED$$sPUBLISHED
000162225 980__ $$aARTICLE