2002/09/19 by Dusan Keres, Dušan Kereš, Min S. Yun +1
Chemistry · Physics and Astronomy · #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Spectroscopy and Laser Applications #astro-ph
paper · pdf · doi:10.1086/344820
published as Astrophys.J. 582 (2003) 659 · 16 pages, 11 figures uses aastex.cls and emulateapj5.sty. Accepted for publication in ApJ
arxiv created 2002/09/19 · openalex publication_date 2003/01/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We derive a nonparametric CO luminosity function using an FIR- and an optical B -band-selected sample of the galaxies included in the FCRAO Extragalactic CO Survey. The FIR-selected sample is defined using the IRAS bright galaxy samples (BGS; IRAS 60 μm flux density ≥5.24 Jy). Although our CO sample is not complete, the normalization using the BGS reproduces the IRAS 60 μm luminosity function in excellent agreement with those found in the literature. Similarly, a B -band-selected sample defined using the Revised Shapley-Ames catalog is used to derive a CO luminosity function for a comparison. A Schechter function describes both the derived CO luminosity functions reasonably well. Adopting the standard CO-to-H 2 conversion factor, we derive a molecular gas density of ρ = (3.1 ± 1.2) × 10 7 h M ☉ Mpc -3 for the local volume. Combining with the measurements of the local H I mass density and the helium contribution, we estimate that the total mass density of cold neutral gas in the local universe is Ω gas = (4.3 ± 1.1) × 10 -4 h -1 , which is about 20% of the total stellar mass density Ω * .