Observational Searches for High-Redshift Galaxies Hosting Population III Stars

We report our photometric search for high-redshift galaxies hosting Population III (Pop III) stars based on deep imaging data obtained in the Subaru Deep Field. By combining the data obtained with broad-band, narrow-band, and intermediate-band filters, we searched for galaxies emitting strong Ly alpha and HeII lambda 1640 emission lines ("dual emitters"), that are promising candidates for galaxies hosting Pop III stars. We found no convincing candidates for such primeval galaxies with SFRPopIII >= 2M(circle dot) Yr(-1) in a volume of 4 x 10(5) Mpc(3) at z similar to 4. This result disfavors low-feedback models for Pop III star clusters proposed so far. Our result gives the first observational upper limit on the Pop III SFR density of SFRDPopIII < 5 x 10(-6) M-circle dot yr(-1) Mpc(-3). This new selection method to search for galaxies hosting Pop III stars should be useful in near-future narrow-band surveys with the next-generation wide-field observational facilities such as Hyper Suprime-Cam on the Subaru telescope, that enables us to identify Pop III stars in high-redshift galaxies.