TY - JOUR
T1 - 3D-HST emission line galaxies at z ∼ 2
T2 - Discrepancies in the optical/UV star formation rates
AU - Zeimann, Gregory R.
AU - Ciardullo, Robin
AU - Gebhardt, Henry
AU - Gronwall, Caryl
AU - Schneider, Donald P.
AU - Hagen, Alex
AU - Bridge, Joanna S.
AU - Feldmeier, John
AU - Trump, Jonathan R.
PY - 2014/8/1
Y1 - 2014/8/1
N2 - 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.
AB - 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.
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U2 - 10.1088/0004-637X/790/2/113
DO - 10.1088/0004-637X/790/2/113
M3 - Article
AN - SCOPUS:84904560443
SN - 0004-637X
VL - 790
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 113
ER -