Nimish P. Hathi, Bahram Mobasher, Peter Capak, Wei-Hao Wang, Henry C. Ferguson
We present near-infrared (NIR; J & Ks) survey of the Great Observatories Origins Deep Survey-North (GOODS-N) field. The imaging data were obtained using the MOIRCS instrument on the 8.2m Subaru and the WIRCam instrument on the 3.6m Canada-France-Hawaii Telescope (CFHT). These observations fulfill a serious wavelength gap in the GOODS-N data - i.e., lack of deep NIR observations. We combine the Subaru/MOIRCS and CFHT/WIRCam archival data to generate deep J and Ks band images, covering the full GOODS-N field (\sim169 sq. arcmin) to an AB magnitude limit of \sim25 mag (3{\sigma}). We applied z'-band dropout color selection criteria, using the NIR data generated here. We have identified two possible Lyman Break Galaxy (LBG) candidates at z\gtrsim6.5 with J\lesssim24.5. The first candidate is a likely LBG at z\simeq6.5 based on a weak spectral feature tentatively identified as Ly{\alpha} line in the deep Keck/DEIMOS spectrum, while the second candidate is a possible LBG at z\simeq7 based on its photometric redshift. These z'-dropout objects, if confirmed, are among the brightest such candidates found so far. At z\gtrsim6.5, their star formation rate is estimated as 100-200 solar mass per year. If they continue to form stars at this rate, they assemble a stellar mass of \sim5x10^10 solar mass after about 400 million years, becoming the progenitors of massive galaxies observed at z\simeq5. We study the implication of the z'-band dropout candidates discovered here, in constraining the bright-end of the luminosity function and understanding the nature of high redshift galaxies.
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http://arxiv.org/abs/1207.5798
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