A Subaru Search for LymanαEmitters atz= 5.8 with an Intermediate-Band Filter

We present the results of a survey for Ly α emitters at z ≈ 5.8 using a new intermediate-band filter centered at λc ≈ 8275 \,Å with ΔλFWHM ≈ 340 \,Å (i.e., spectroscopic resolution is R ≈ 24 ) and a combination with a traditional narrow-band centered at λc ≈ 8150 \,Å with ΔλFWHM ≈ 120 \,Å ( R ≈ 68 ). Our observations were made using the Subaru Prime Focus Camera, Suprime-Cam, on the 8.2m Subaru telescope in a sky area surrounding the high-redshift quasar SDSSp J104433.04 $-$ 012522.2 at $z = 5.74$ , covering an effective sky area of ≈ 720 \;arcmin² . In this survey, we have found four Ly α -emitter candidates from the intermediate-band image ( z ≈ 5.8 with Δ z ≈ 0.3 ). Combined with our previous results based on the NB816 imaging, we discuss the star-formation activity in galaxies between z ≈ 5.7 and z ≈ 5.9 .