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We present results from an imaging and spectroscopic study of four strongMgII absorbers of W(2796) >~ 1 Ang revealed by the afterglow of GRB060418 atz_GRB=1.491. These absorbers, at z=0.603,0.656,1.107 and z_GRB, exhibit largeion abundances that suggest neutral gas column densities characteristic ofdamped Lya systems. The imaging data include optical images obtained using LRISon the Keck I telescope and using ACS on board HST, and near-infrared H-bandimages obtained using PANIC on the Magellan Baade Telescope and K'-band imagesobtained using NIRC2 with LGSAO on the Keck II telescope. These images revealsix distinct objects at <~ 3.5'' of the afterglow's position, two of whichexhibit well-resolved mature disk morphology, one shows red colors, and threeare blue compact sources. Follow-up spectroscopic observations using LRISconfirm that one of the disk galaxies coincides with the MgII absorber atz=0.656. The observed broad-band spectral energy distributions of the seconddisk galaxy and the red source indicate that they are associated with theabsorbers at z=0.603 and z=1.107, respectively. These results show that strongMgII absorbers identified in GRB afterglow spectra are associated with typicalgalaxies of luminosity ~ (0.1-1) L* at impact parameter <~ 10 h^-1 kpc. Theclose angular separation would preclude easy detections toward a bright quasar.Finally, we associate the remaining three blue compact sources with the GRBhost galaxy, noting that they are likely star-forming knots located atprojected distances 2-12 h^-1 kpc from the afterglow. At the afterglow'sposition, we derive a 2-sigma upper limit to the underlying SFR intensity of0.0074 M_sun yr^-1 kpc^-2.

An Imaging and Spectroscopic Study of Four Strong MgII Absorbers Revealed By GRB060418