| Speaker: | Kazuaki Ota (RIKEN) |
|---|---|
| Title: | Deep Surveys of z=7 Ly-alpha Emitting Galaxies with Subaru Telescope:Implications for Galaxy Evolution and Reionization |
| Date (JST): | Wed, Aug 05, 2009, 11:00 - 12:00 |
| Place: | Seminar Room at IPMU Prefab. B |
| Related File: | 122.pdf |
| Abstract: |
We conducted a deep narrowband NB973 filter (FWHM=200A centered at 9755A) survey of z=7 Ly-alpha emitting galaxies (LAEs) in the Subaru/XMM-Newton Deep Field, using the fully depleted CCDs newly installed on the Subaru Telescope Suprime-Cam, which has the highest sensitivity at ~1um. Reaching the depth ~0.5 mag deeper than the previous survey that discovered a z=6.96 LAE, we detected at least two probable z=7 LAE candidates in addition to a few less robust but possible candidates. Even if we assume that all the candidates are real, the LAE number density at z=7 is significantly lower than those at the later epochs z=5.7 and 6.6 to the limit of L(Ly-alpha) ~ 6 x 1042 erg/s. This number deficit might reflect the larger neutral hydrogen fraction at z=7, supporting the late reionization suggested by the previous surveys of z=5.7-7 LAEs, z~6 quasars and z>6 gamma-ray bursts. I will also present the constraint on the stellar population of a z=6.96 LAE (IOK-1) using the Spitzer mid-infrared imaging of the Subaru Deep Field and its implication for galaxy evolution and reionization. |
