%0 Generic %1 Yuan2011 %A Yuan, T. T. %A Kewley, L. J. %A Swinbank, A. M. %A Richard, J. %A Livermore, R. C. %D 2011 %K high-z metallicity %T Metallicity Gradient of a Lensed Face-on Spiral Galaxy at Redshift 1.49 %U http://arxiv.org/abs/1103.3277 %X We present the first metallicity gradient measurement for a grand-design face-on spiral galaxy at z$\sim$1.5. This galaxy has been magnified by a factor of 22$\times$ by a massive, X-ray luminous galaxy cluster MACS\,J1149.5+2223 at z=0.544. Using the Laser Guide Star Adaptive Optics aided integral field spectrograph OSIRIS on KECK II, we target the \ha\ emission and achieve a spatial resolution of 0\farcs1, corresponding to a source plane resolution of 170 parsec. The galaxy has well-developed spiral arms and the nebular emission line dynamics clearly indicate a rotationally supported disk with V$_rot$/ $\sigma$ $\sim$ 4. The best-fit disk velocity field model yields a maximum rotation of V$_rot$$i$=150$\pm$15 km s$^-1$, and a dynamical mass of M$_dyn$=1.3$\pm0.2\times10^10$csc$^2$(i)\,M$_ødot$ (within 2.5\,kpc), where the inclination angle i=45$\pm10^\circ$. Based on the \nii\ and \ha\ ratios, we measured the radial chemical abundance gradient from the inner hundreds of parsecs out to $\sim$5 kilo-parsecs. The slope of the gradient is -0.16$\pm$0.02 dex kpc$^-1$, significantly steeper than the gradient of late-type or early-type galaxies in the local universe. If representative of disk galaxies at z$\sim$1.5, our results support an "inside-out" disk formation scenario in which early infall/collapse in the galaxy center builds a chemically enriched nucleus, followed by slow enrichment of the disk over the next 9 Gyrs.

@misc{Yuan2011, abstract = { We present the first metallicity gradient measurement for a grand-design face-on spiral galaxy at z$\sim$1.5. This galaxy has been magnified by a factor of 22$\times$ by a massive, X-ray luminous galaxy cluster MACS\,J1149.5+2223 at z=0.544. Using the Laser Guide Star Adaptive Optics aided integral field spectrograph OSIRIS on KECK II, we target the \ha\ emission and achieve a spatial resolution of 0\farcs1, corresponding to a source plane resolution of 170 parsec. The galaxy has well-developed spiral arms and the nebular emission line dynamics clearly indicate a rotationally supported disk with V$_{rot}$/ $\sigma$ $\sim$ 4. The best-fit disk velocity field model yields a maximum rotation of V$_{rot}$${\it \sin{i}}$=150$\pm$15 km s$^{-1}$, and a dynamical mass of M$_{dyn}$=1.3$\pm0.2\times10^{10}${\it csc$^2$(i)}\,M$_{\odot}$ (within 2.5\,kpc), where the inclination angle i=45$\pm10^{\circ}$. Based on the \nii\ and \ha\ ratios, we measured the radial chemical abundance gradient from the inner hundreds of parsecs out to $\sim$5 kilo-parsecs. The slope of the gradient is -0.16$\pm$0.02 dex kpc$^{-1}$, significantly steeper than the gradient of late-type or early-type galaxies in the local universe. If representative of disk galaxies at z$\sim$1.5, our results support an "inside-out" disk formation scenario in which early infall/collapse in the galaxy center builds a chemically enriched nucleus, followed by slow enrichment of the disk over the next 9 Gyrs. }, added-at = {2011-03-18T05:29:31.000+0100}, author = {Yuan, T. T. and Kewley, L. J. and Swinbank, A. M. and Richard, J. and Livermore, R. C.}, biburl = {https://www.bibsonomy.org/bibtex/2f602b6ddcdf9c6183ee1ff482363cf5b/miki}, description = {[1103.3277] Metallicity Gradient of a Lensed Face-on Spiral Galaxy at Redshift 1.49}, interhash = {8ba88b0422e8af22e70a04f13be554a0}, intrahash = {f602b6ddcdf9c6183ee1ff482363cf5b}, keywords = {high-z metallicity}, note = {cite arxiv:1103.3277 Comment: 4 figures, ApJL accepted}, timestamp = {2011-03-18T05:29:31.000+0100}, title = {Metallicity Gradient of a Lensed Face-on Spiral Galaxy at Redshift 1.49}, url = {http://arxiv.org/abs/1103.3277}, year = 2011 }