【場所】国立天文台・三鷹 中央棟（北）1階 講義室
【発表者（敬称略）】澁谷 隆俊（総研大 D2・三鷹、指導教員 : 家 正則 & 柏川 伸成）
【タイトル】The First Systematic Survey for Lyman Alpha Emitters at z=7.3
We have performed deep imaging survey for Lyman alpha emitters (LAEs) at redshift 7.3 in two blank fields, the Subaru Deep Field (SDF) and the Subaru/XMM-Newton Deep Field (SXDF), using the Subaru/Suprime-Cam equipped with new red-sensitive CCDs and a new narrow-band filter NB1006 (center=10,052A, FWHM=214A).
The limiting AB magnitudes (2″, 5sgm) attained were NB1006=24.8 and 24.6 with effective integration times of 17.2 and 14.3 hours, respectively, in the SDF and the SXDF.
By comparing the NB1006 magnitudes of detected objects with the archived Suprime-Cam data taken at other in shorter wavelength bands, we identified four objects that exhibit a luminosity excess in the wavelengths covered by the NB1006 filter. Carrying out deep follow-up spectroscopy of three candidates out of them using Subaru/FOCAS and Keck/DEIMOS, we identified one of them as a real z=7.215 LAE, and another as a tentative z=7.288 LAE.
In the colloquium, I will demonstrate how to constrain the neutral fraction at z=7.3 using this LAE.