CLASH: DISCOVERY OF A BRIGHT z ≃ 6.2 DWARF GALAXY QUADRUPLY LENSED BY MACS J0329.6-0211

We report the discovery of a z(phot) = 6.18(-0.07)(+0.05) (95% confidence level) dwarf galaxy, lensed into four images by the galaxy cluster MACS J0329.6-0211 (z(l) = 0.45). The galaxy is observed as a high-redshift dropout in HST/ACS/WFC3 CLASH and Spitzer/IRAC imaging. Its redshift is securely determined due to a clear detection of the Lyman break in the 18-band photometry, making this galaxy one of the highest-redshift multiply lensed objects known to date with an observed magnitude of F125W = 24.00 +/- 0.04 AB mag for its most magnified image. We also present the first strong-lensing analysis of this cluster uncovering 15 additional multiply imaged candidates of five lower-redshift sources spanning the range z(s) similar or equal to 2-4. The mass model independently supports the high photometric redshift and reveals magnifications of 11.6(-4.1)(+8.9), 17.6(-3.9)(+6.2), 3.9(-1.7)(+3.0), and 3.7(-0.2)(+1.3), respectively, for the four images of the high-redshift galaxy. By delensing the most magnified image we construct an image of the source with a physical resolution of similar to 200 pc when the universe was similar to 0.9 Gyr old, where the z similar or equal to 6.2 galaxy occupies a source-plane area of approximately 2.2 kpc(2). Modeling the observed spectral energy distribution using population synthesis models, we find a demagnified stellar mass of similar to 10(9) M-circle dot, subsolar metallicity (Z/Z(circle dot) similar to 0.5), low dust content (A(V) similar to 0.1 mag), a demagnified star formation rate (SFR) of similar to 3.2 M-circle dot yr(-1), and a specific SFR of similar to 3.4 Gyr (1), all consistent with the properties of local dwarf galaxies.