Year: 2014
Type: article
Abstract: We examine the statistics of the low-redshift Lyα forest from smoothed particle hydrodynamic simulations in light of recent improvements in the estimated evolution of the cosmic ultraviolet background (UVB) and recent observations from the Cosmic Origins Spectrograph (COS). We find that the value of the metagalactic photoionization rate (Γ HI ) required by our simulations to match the observed properties of the low-redshift Lyα forest is a factor of five larger than the value predicted by state-of-the art models for the evolution of this quantity. This mismatch in Γ HI results in the mean flux decrement of the Lyα forest being overpredicted by at least a factor of two (a 10σ discrepancy with observations) and a column density distribution of Lyα forest absorbers systematically and significantly elevated compared to observations over nearly two decades in column density. We examine potential resolutions to this mismatch and find that either conventional sources of ionizing photons (galaxies and quasars) must contribute considerably more than current observational estimates or our theoretical understanding of the low-redshift universe is in need of substantial revision.
Authors: Juna A. Kollmeier, David H. Weinberg, Benjamin D. Oppenheimer, Francesco Haardt, Neal Katz, Romeel Davé, Mark Fardal, Piero Madau, Charles Danforth, Amanda B. Ford, Molly S. Peeples, Joseph McEwen
Institutions: Carnegie Institution for Science, Carnegie Observatories, The Ohio State University, University of Colorado Boulder, University of Insubria, University of Massachusetts Amherst, African Institute for Mathematical Sciences, South African Astronomical Observatory, University of the Western Cape, University of California, Santa Cruz, University of Arizona, Space Telescope Science Institute
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: THE STUDY OF THE FORMATION, MERGING HISTORY, AND ENVIRONMENTAL IMPACT OF THE MASSIVE BLACK HOLES (MBHS) THAT ARE UBIQUITOUS IN THE NUCLEI OF LUMINOUS, RECENT NUMERICAL SIMULATIONS SHOW THAT GALAXIES FORMING IN A COLD DARK MATTER UNIVERSE GAIN MUCH OF THEIR MASS THROUGH "COLD" ACCRETION ALONG FILAMEN, Collaborative Research: CDI- Type II: Towards Analyzing Complex Petascale Datasets: The Milky Way Laboratory
OpenAlex ID: W2157312258