%0 Generic %1 Wuyts2012 %A Wuyts, Eva %A Rigby, Jane R. %A Sharon, Keren %A Gladders, Michael D. %D 2012 %K fundamental mass metallicity relation %T Constraints on the low-mass end of the mass-metallicity relation at z=1-2 from lensed galaxies %U http://arxiv.org/abs/1202.5267 %X We present multi-wavelength imaging and near-IR spectroscopy for ten gravitationally lensed galaxies at 0.9<z<2.5 selected from a new, large sample of strong lens systems in the Sloan Digital Sky Survey (SDSS) DR7. We derive stellar masses from the rest-frame UV to near-IR spectral energy distributions, star formation rates (SFR) from the dust-corrected Ha flux, and metallicities from the N II/Ha flux ratio. We combine the lensed galaxies with a sample of sixty star-forming galaxies from the literature in the same redshift range for which measurements of N II/Ha have been published. Due to the lensing magnification, the lensed galaxies probe intrinsic stellar masses that are on average a factor of 11 lower than have been studied so far at these redshifts. We measure an evolution of 0.16+/-0.06 dex in the mass-metallicity relation between z~1.4 and z~2.2. In contrast to previous claims, the redshift evolution is smaller at low stellar masses. The local fundamental relation between metallicity, stellar mass and SFR from Mannucci et al.(2010) underestimates the metallicity by 0.5+/-0.3 dex for stellar masses below 10^9.8 Msun. We see no correlation between SFR and metallicity at fixed stellar mass and thus there is no evidence for the existence of a fundamental relation for the high specific star formation rates at z=1-2 probed by this sample. Using the Kennicutt-Schmidt law to infer gas fractions, we investigate the importance of gas inflows and outflows on the shape of the mass-metallicity relation using simple analytical models. This suggests that the Maiolino et al.(2008) calibration of the N II/Ha flux ratio is biased high. We conclude that both an absolute metallicity calibration and direct measurements of the gas mass are needed to use the observed mass-metallicity relation to gain insight into the impact of gas flows on the chemical evolution of galaxies.

@misc{Wuyts2012, abstract = { We present multi-wavelength imaging and near-IR spectroscopy for ten gravitationally lensed galaxies at 0.9<z<2.5 selected from a new, large sample of strong lens systems in the Sloan Digital Sky Survey (SDSS) DR7. We derive stellar masses from the rest-frame UV to near-IR spectral energy distributions, star formation rates (SFR) from the dust-corrected Ha flux, and metallicities from the [N II]/Ha flux ratio. We combine the lensed galaxies with a sample of sixty star-forming galaxies from the literature in the same redshift range for which measurements of [N II]/Ha have been published. Due to the lensing magnification, the lensed galaxies probe intrinsic stellar masses that are on average a factor of 11 lower than have been studied so far at these redshifts. We measure an evolution of 0.16+/-0.06 dex in the mass-metallicity relation between z~1.4 and z~2.2. In contrast to previous claims, the redshift evolution is smaller at low stellar masses. The local fundamental relation between metallicity, stellar mass and SFR from Mannucci et al.(2010) underestimates the metallicity by 0.5+/-0.3 dex for stellar masses below 10^9.8 Msun. We see no correlation between SFR and metallicity at fixed stellar mass and thus there is no evidence for the existence of a fundamental relation for the high specific star formation rates at z=1-2 probed by this sample. Using the Kennicutt-Schmidt law to infer gas fractions, we investigate the importance of gas inflows and outflows on the shape of the mass-metallicity relation using simple analytical models. This suggests that the Maiolino et al.(2008) calibration of the [N II]/Ha flux ratio is biased high. We conclude that both an absolute metallicity calibration and direct measurements of the gas mass are needed to use the observed mass-metallicity relation to gain insight into the impact of gas flows on the chemical evolution of galaxies. }, added-at = {2012-02-24T17:12:47.000+0100}, author = {Wuyts, Eva and Rigby, Jane R. and Sharon, Keren and Gladders, Michael D.}, biburl = {https://www.bibsonomy.org/bibtex/2be50fa26730b093339887e49bd759973/miki}, description = {[1202.5267] Constraints on the low-mass end of the mass-metallicity relation at z=1-2 from lensed galaxies}, interhash = {e064864863f2937e4867d04f6aa69b61}, intrahash = {be50fa26730b093339887e49bd759973}, keywords = {fundamental mass metallicity relation}, note = {cite arxiv:1202.5267Comment: 16 pages, 9 figures, submitted to the Astrophysical Journal}, timestamp = {2012-02-24T17:12:47.000+0100}, title = {Constraints on the low-mass end of the mass-metallicity relation at z=1-2 from lensed galaxies}, url = {http://arxiv.org/abs/1202.5267}, year = 2012 }