Gravitationally lensed galaxies at 2 < z < 3.5: direct abundance measurements of Ly α emitters
Articolo
Data di Pubblicazione:
2012
Citazione:
Gravitationally lensed galaxies at 2 < z < 3.5: direct abundance measurements of Ly α emitters / L. Christensen, P. Laursen, J. Richard, J. Hjorth, B. Milvang Jensen, M. Dessauges Zavadsky, M. Limousin, C. Grillo, H. Ebeling. - In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. - ISSN 0035-8711. - 427:3(2012), pp. 1973-1982. [10.1111/j.1365-2966.2012.22007.x]
Abstract:
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.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
gravitational lensing: strong; galaxies: abundances; galaxies: evolution; galaxies: high-redshift
Elenco autori:
L. Christensen, P. Laursen, J. Richard, J. Hjorth, B. Milvang Jensen, M. Dessauges Zavadsky, M. Limousin, C. Grillo, H. Ebeling
Link alla scheda completa: