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

Journal Article · Fri Aug 01 04:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/790/2/113· OSTI ID:22365518

Zeimann, Gregory R.; Ciardullo, Robin; Gebhardt, Henry; Gronwall, Caryl; Schneider, Donald P.; Hagen, Alex; Bridge, Joanna S.; Trump, Jonathan R. ^[1]; Feldmeier, John ^[2]

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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)

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.

• OSTI ID: 22365518
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 790; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
CONVERSION
EMISSION
EVOLUTION
FLUX DENSITY
GALAXIES
METALLICITY
OXYGEN
RED SHIFT
SPECTROSCOPY
STAR EVOLUTION
STARS
TELESCOPES
UNIVERSE