000002143 001__ 2143
000002143 005__ 20160701171659.0
000002143 0247_ $$2DOI$$a10.1088/0004-637X/790/1/35
000002143 037__ $$aASTROimport-300
000002143 100__ $$aLi, C.
000002143 245__ $$aThe VMC Survey. XI. Radial Stellar Population Gradients in the Galactic Globular Cluster 47 Tucanae
000002143 260__ $$c2014
000002143 520__ $$aWe present a deep near-infrared color-magnitude diagram of the Galactic globular cluster 47 Tucanae, obtained with the Visible and Infrared Survey Telescope for Astronomy (VISTA) as part of the VISTA near-infrared Y, J, K s survey of the Magellanic System (VMC). The cluster stars comprising both the subgiant and red giant branches exhibit apparent, continuous variations in color-magnitude space as a function of radius. Subgiant branch stars at larger radii are systematically brighter than their counterparts closer to the cluster core; similarly, red-giant-branch stars in the cluster's periphery are bluer than their more centrally located cousins. The observations can very well be described by adopting an age spread of ~0.5 Gyr as well as radial gradients in both the cluster's helium abundance (Y) and metallicity (Z), which change gradually from (Y = 0.28, Z = 0.005) in the cluster core to (Y = 0.25, Z = 0.003) in its periphery. We conclude that the cluster's inner regions host a significant fraction of second-generation stars, which decreases with increasing radius; the stellar population in the 47 Tuc periphery is well approximated by a simple stellar population. 
000002143 700__ $$a de Grijs, R.
000002143 700__ $$a Deng, L.
000002143 700__ $$a Rubele, S.
000002143 700__ $$a Wang, C.
000002143 700__ $$a Bekki, K.
000002143 700__ $$a Cioni, M.-R. L.
000002143 700__ $$a Clementini, G.
000002143 700__ $$a Emerson, J.
000002143 700__ $$a For, B.-Q.
000002143 700__ $$a Girardi, L.
000002143 700__ $$a Groenewegen, M. A. T.
000002143 700__ $$a Guandalini, R.
000002143 700__ $$a Gullieuszik, M.
000002143 700__ $$a Marconi, M.
000002143 700__ $$a Piatti, A. E.
000002143 700__ $$a Ripepi, V.
000002143 700__ $$a van Loon, J. T.
000002143 773__ $$c35$$i1$$pThe Astrophysical Journal$$v790$$y2014
000002143 85642 $$ahttp://esoads.eso.org/abs/2014ApJ...790...35L
000002143 905__ $$apublished in
000002143 980__ $$aREFERD