TY - JOUR
T1 - Gravitationally lensed galaxies at 2 < z < 3.5
T2 - direct abundance measurements of Ly alpha emitters
AU - Christensen, Lise Bech
AU - Laursen, Peter
AU - Richard, Johan
AU - Hjorth, Jens
AU - Milvang-Jensen, Bo
AU - Grillo, Claudio
AU - Limousin, Marceau Karim Emile
AU - Ebeling, H.
AU - Dessauges-Zavadsky, M.
PY - 2012/12/11
Y1 - 2012/12/11
N2 - Strong gravitational lensing magnifies the flux from distant galaxies, allowing us to detect emission lines that would otherwise fall below the detection threshold for medium-resolution spectroscopy. Here we present the detection of temperature-sensitive oxygen emission lines from three galaxies at 2 ≲ z ≲ 3.5, which enables us to directly determine the oxygen abundances and thereby double the number of galaxies at z > 2 for which this has been possible. The three galaxies have ∼10percent solar oxygen abundances in agreement with strong emission-line diagnostics. Carbon and nitrogen ratios relative to oxygen are subsolar as expected for young metal-poor galaxies. Two of the galaxies are Lyman α (Lyα) emitters with rest-frame equivalent widths of 20 and 40Å, respectively, and their high magnification factors allow us for the first time to gain insight into the physical characteristics of high-redshift Lyα emitters. Using constraints from the physical properties of the galaxies, we accurately reproduce their line profiles with radiative transfer models. The models show a relatively small outflow in agreement with the observed small velocity offsets between nebular emission and interstellar absorption lines.
AB - Strong gravitational lensing magnifies the flux from distant galaxies, allowing us to detect emission lines that would otherwise fall below the detection threshold for medium-resolution spectroscopy. Here we present the detection of temperature-sensitive oxygen emission lines from three galaxies at 2 ≲ z ≲ 3.5, which enables us to directly determine the oxygen abundances and thereby double the number of galaxies at z > 2 for which this has been possible. The three galaxies have ∼10percent solar oxygen abundances in agreement with strong emission-line diagnostics. Carbon and nitrogen ratios relative to oxygen are subsolar as expected for young metal-poor galaxies. Two of the galaxies are Lyman α (Lyα) emitters with rest-frame equivalent widths of 20 and 40Å, respectively, and their high magnification factors allow us for the first time to gain insight into the physical characteristics of high-redshift Lyα emitters. Using constraints from the physical properties of the galaxies, we accurately reproduce their line profiles with radiative transfer models. The models show a relatively small outflow in agreement with the observed small velocity offsets between nebular emission and interstellar absorption lines.
U2 - 10.1111/j.1365-2966.2012.22007.x
DO - 10.1111/j.1365-2966.2012.22007.x
M3 - Journal article
SN - 0035-8711
VL - 427
SP - 1973
EP - 1982
JO - Royal Astronomical Society. Monthly Notices
JF - Royal Astronomical Society. Monthly Notices
IS - 3
ER -