TY - JOUR
T1 - The Mosdef survey
T2 - Detection of [O III]λ4363 and the direct-method oxygen abundance of a star-forming galaxy at z = 3.08
AU - Sanders, Ryan L.
AU - Shapley, Alice E.
AU - Kriek, Mariska
AU - Reddy, Naveen A.
AU - Freeman, William R.
AU - Coil, Alison L.
AU - Siana, Brian
AU - Mobasher, Bahram
AU - Shivaei, Irene
AU - Price, Sedona H.
AU - Groot, Laura De
N1 - Publisher Copyright:
© 2016. The American Astronomical Society. All rights reserved.
PY - 2016/7/10
Y1 - 2016/7/10
N2 - We present measurements of the electron-temperature-based oxygen abundance for a highly star-forming galaxy at z = 3.08, COSMOS-1908. This is the highest redshift at which [O iii]λ4363 has been detected and the first time that this line has been measured at z > 2. We estimate an oxygen abundance of 12 + log(O/H) = 8.00-0.14+0.13. This galaxy is a low-mass (109.3 M⊙), highly star-forming (∼50M⊙ yr-1) system that hosts a young stellar population (∼160 Myr). We investigate the physical conditions of the ionized gas in COSMOS-1908 and find that this galaxy has a high ionization parameter, little nebular reddening (E(B-V)gas < 0.14), and a high electron density (ne ∼ 500 cm-3). We compare the ratios of strong oxygen, neon, and hydrogen lines to the direct-method oxygen abundance for COSMOS-1908 and additional star-forming galaxies at z=0-1.8 with [O iii]λ4363 measurements and show that galaxies at z ∼ 1-3 follow the same strong-line correlations as galaxies in the local universe. This agreement suggests that the relationship between ionization parameter and O/H is similar for z∼0 and high-redshift galaxies. These results imply that metallicity calibrations based on lines of oxygen, neon, and hydrogen do not strongly evolve with redshift and can reliably estimate abundances out to Z ∼ 3, paving the way for robust measurements of the evolution of the mass-metallicity relation to high redshift.
AB - We present measurements of the electron-temperature-based oxygen abundance for a highly star-forming galaxy at z = 3.08, COSMOS-1908. This is the highest redshift at which [O iii]λ4363 has been detected and the first time that this line has been measured at z > 2. We estimate an oxygen abundance of 12 + log(O/H) = 8.00-0.14+0.13. This galaxy is a low-mass (109.3 M⊙), highly star-forming (∼50M⊙ yr-1) system that hosts a young stellar population (∼160 Myr). We investigate the physical conditions of the ionized gas in COSMOS-1908 and find that this galaxy has a high ionization parameter, little nebular reddening (E(B-V)gas < 0.14), and a high electron density (ne ∼ 500 cm-3). We compare the ratios of strong oxygen, neon, and hydrogen lines to the direct-method oxygen abundance for COSMOS-1908 and additional star-forming galaxies at z=0-1.8 with [O iii]λ4363 measurements and show that galaxies at z ∼ 1-3 follow the same strong-line correlations as galaxies in the local universe. This agreement suggests that the relationship between ionization parameter and O/H is similar for z∼0 and high-redshift galaxies. These results imply that metallicity calibrations based on lines of oxygen, neon, and hydrogen do not strongly evolve with redshift and can reliably estimate abundances out to Z ∼ 3, paving the way for robust measurements of the evolution of the mass-metallicity relation to high redshift.
KW - galaxies: ISM
KW - galaxies: evolution
KW - galaxies: high-redshift
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U2 - 10.3847/2041-8205/825/2/L23
DO - 10.3847/2041-8205/825/2/L23
M3 - Article
AN - SCOPUS:84978520104
SN - 2041-8205
VL - 825
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L23
ER -