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Title: 3D-HST emission line galaxies at z ∼ 2: discrepancies in the optical/UV star formation rates

We use Hubble Space Telescope near-IR grism spectroscopy to examine the Hβ line strengths of 260 star-forming galaxies in the redshift range 1.90 < z < 2.35. We show that at these epochs, the Hβ star formation rate (SFR) is a factor of ∼1.8 higher than what would be expected from the systems' rest-frame UV flux density, suggesting a shift in the standard conversion between these quantities and SFR. We demonstrate that at least part of this shift can be attributed to metallicity, as Hβ is more enhanced in systems with lower oxygen abundance. This offset must be considered when measuring the SFR history of the universe. We also show that the relation between stellar and nebular extinction in our z ∼ 2 sample is consistent with that observed in the local universe.
Authors:
; ; ; ; ; ; ;  [1] ;  [2]
  1. Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)
  2. Department of Physics and Astronomy, Youngstown State University, Youngstown, OH 44555 (United States)
Publication Date:
OSTI Identifier:
22365518
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 790; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; CONVERSION; EMISSION; EVOLUTION; FLUX DENSITY; GALAXIES; METALLICITY; OXYGEN; RED SHIFT; SPECTROSCOPY; STAR EVOLUTION; STARS; TELESCOPES; UNIVERSE