2013/12/22 by F. Walter, R. Decarli, M. Sargent +20 · 1 citation
Physics and Astronomy · #Astrophysics and Star Formation Studies #COSMIC cancer database #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Hubble Deep Field #Hubble Ultra-Deep Field #Line (geometry) #Luminosity #Luminosity function #Plateau de Bure Interferometer #Redshift #astro-ph.CO
paper · pdf · doi:10.1088/0004-637x/782/2/79
Accepted for publication in ApJ
arxiv created 2013/12/22 · openalex publication_date 2014/01/30 · arxiv updated 2015/06/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present direct constraints on the CO luminosity function at high redshift and the resulting cosmic evolution of the molecular gas density, ( z ), based on a blind molecular line scan in the Hubble Deep Field North (HDF-N) using the IRAM Plateau de Bure Interferometer. Our line scan of the entire 3 mm window (79–115 GHz) covers a cosmic volume of ∼7000 Mpc 3 , and redshift ranges z < 0.45, 1.01 < z < 1.89 and z > 2. We use the rich multiwavelength and spectroscopic database of the HDF-N to derive some of the best constraints on CO luminosities in high redshift galaxies to date. We combine the blind CO detections in our molecular line scan (presented in a companion paper) with stacked CO limits from galaxies with available spectroscopic redshifts (slit or mask spectroscopy from Keck and grism spectroscopy from the Hubble Space Telescope ) to give first blind constraints on high- z CO luminosity functions and the cosmic evolution of the H 2 mass density ( z ) out to redshifts z ∼ 3. A comparison to empirical predictions of ( z ) shows that the securely detected sources in our molecular line scan already provide significant contributions to the predicted ( z ) in the redshift bins 〈 z 〉 ∼ 1.5 and 〈 z 〉 ∼ 2.7. Accounting for galaxies with CO luminosities that are not probed by our observations results in cosmic molecular gas densities ( z ) that are higher than current predictions. We note, however, that the current uncertainties (in particular the luminosity limits, number of detections, as well as cosmic volume probed) are significant, a situation that is about to change with the emerging ALMA observatory.