The End of the Reionization Epoch Probed by Lyα Emitters at z = 6.5 in the Subaru Deep Field
/ Authors
N. Kashikawa, K. Shimasaku, M. Malkan, M. Doi, Y. Matsuda, M. Ouchi, Y. Taniguchi, C. Ly, T. Nagao, M. Iye
and 9 more authors
K. Motohara, T. Murayama, K. Murozono, K. Nariai, K. Ohta, S. Okamura, T. Sasaki, Y. Shioya, M. Umemura
/ Abstract
We report an extensive search for Lyα emitters (LAEs) at z = 6.5 in the Subaru Deep Field. Subsequent spectroscopy with Subaru and Keck identified eight more LAEs, giving a total of 17 spectroscopically confirmed LAEs at z = 6.5. Based on this spectroscopic sample of 17, complemented by a photometric sample of 58 LAEs, we have derived a more accurate Lyα luminosity function of LAEs at z = 6.5, which reveals an apparent deficit at the bright end of ~0.75 mag fainter L*, compared with that observed at z = 5.7. The difference in the LAE luminosity functions between z = 5.7 and 6.5 is significant at the 3 σ level, which is reduced to 2 σ when cosmic variance is taken into account. This result may imply that the reionization of the universe has not been completed at z = 6.5. We found that the spatial distribution of LAEs at z = 6.5 was homogeneous over the field. We discuss the implications of these results for the reionization of the universe.
Journal: The Astrophysical Journal
DOI: 10.1086/504966