The nature of the ISM in galaxies during the star-formation activity peak of the Universe

• DOI: 10.1093/mnras/stu1506
• Publication Date: 2014-08-29T06:52:18Z
• Authors: G. Popping; J. P. Pérez-Beaup...; M. Spaans; S. C. Trager; R. S. Somerville
• Keywords: Cosmology and Nongalactic Astrophysics (astro-ph.CO); 0103 physical sciences; galaxies: formation; FOS: Physical sciences; ISM: atoms; galaxies: evolution; 01 natural sciences; ISM: molecules; galaxies: ISM; ISM: lines and bands; Astrophysics - Cosmology and Nongalactic Astrophysics

We combine a semi-analytic model of galaxy formation, tracking atomic and molecular phases cold gas, with three-dimensional radiative-transfer line tracing code to study the sub-mm emission from species (CO, HCN, [C舁i], [C舁ii], [O舁i]) in galaxies. compare physics that drives formation stars at epoch peak star (SF) Universe (z = 2.0) local find normal star-forming galaxies high redshift have much higher CO-excitation peaks than their counterparts CO cooling takes place excitation levels. ratios increase as function star-formation rate, but are well correlated H2 surface density independent redshift. an [O舁i]/[C舁ii] ratio typical z 1.2 2.0 respect 0. Our results suggest consist denser warmer clouds counterparts. Galaxies belonging tail SF activity already less dense cooler during actual 2.0). use our discuss how future ALMA surveys can best confront predictions constrain models formation.