A Spatially Resolved Map of the Kinematics, Star-Formation and Stellar Mass Assembly in a Star-Forming Galaxy at z=4.9

Understand

We present a detailed study of the spatially resolved kinematics, star-formation and stellar mass in a highly amplified galaxy at z=4.92 behind the lensing cluster MS1358+62.

• We use the observed optical, near- and mid-infrared imaging from HST ACS & NICMOS and Spitzer IRAC to derive the stellar mass and the Gemini/NIFS IFU to investigate the velocity structure of the galaxy from the nebular [OII] emission.
• Using a detailed gravitational lens model, we account for lensing amplification factor 12.+/-2.0 and find that this intrinsically L* galaxy has a stellar mass of M*=7+/-2x10^8Mo, a dynamical mass of Mdyn=3+/-1x10^9csc^2(i)Mo (within of 2kpc) and a star-formation rate of 42+/-8Mo/yr.
• The source-plane UV/optical morphology of this galaxy is dominated by five discrete star-forming regions.