A Consistent Study of Metallicity Evolution at 0.8 < z < 2.6
van Dokkum, Pieter; Bender, Ralf; Tacchella, Sandro; Mendel, J. Trevor; Nelson, Erica J.; Momcheva, Ivelina G.; Brammer, Gabriel B.; Wuyts, Stijn; Seitz, Stella; Wuyts, Eva; Förster Schreiber, Natascha M.; Fossati, Matteo; Renzini, Alvio; Lutz, Dieter; Sharples, Ray M.; Burkert, Andreas; Lang, Philipp; Chan, Jeffrey; Rosario, David; Sternberg, Amiel; Wisnioski, Emily; Genzel, Reinhard; Tacconi, Linda J.; Naab, Thorsten; Davies, Ric; Carollo, C. Marcella; Wilman, David J.; Beifiori, Alessandra; Lilly, Simon J.; Bandara, Kaushala; Kurk, Jaron; Saglia, Roberto P.; Kulkarni, Sandesh K.; Buschkamp, Peter; Eisenhauer, Frank; Mancini, Chiara
Germany, United States, Switzerland, Italy, United Kingdom, Israel
Abstract
We present the correlations between stellar mass, star formation rate (SFR), and the [N II]/Hα flux ratio as an indicator of gas-phase metallicity for a sample of 222 galaxies at 0.8 < z < 2.6 and log (M */M ⊙) = 9.0-11.5 from the LUCI, SINS/zC-SINF, and KMOS3D surveys. This sample provides a unique analysis of the mass-metallicity relation (MZR) over an extended redshift range using consistent data analysis techniques and a uniform strong-line metallicity indicator. We find a constant slope at the low-mass end of the relation and can fully describe its redshift evolution through the evolution of the characteristic turnover mass where the relation begins to flatten at the asymptotic metallicity. At a fixed mass and redshift, our data do not show a correlation between the [N II]/Hα ratio and SFR, which disagrees with the 0.2-0.3 dex offset in [N II]/Hα predicted by the "fundamental relation" between stellar mass, SFR, and metallicity discussed in recent literature. However, the overall evolution toward lower [N II]/Hα at earlier times does broadly agree with these predictions.
Based on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO program IDs 073.B-9018, 074.A-9011, 075.A-0466, 076.A-0527, 078.A-0660, 079.A-0341, 080.A-0330, 080.A-0339, 080.A-0635, 081.A-0672, 082.A-0396, 083.A-0781, 087.A-0081, 088.A-0202, 088.A-0209, 091.A-0126, 092.A-0082, and 092.A-0091) and at the Large Binocular Telescope (LBT) on Mt. Graham in Arizona. This work is further based on observations taken by the 3D-HST Treasury Program (GO 12177 and 12328) with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.