We report the Subaru Hyper Suprime-Cam ( HSC ) discovery of two Ly \alpha blobs ( LABs ) , dubbed z70-1 and z49-1 at z = 6.965 and z = 4.888 respectively , that are Ly \alpha emitters with a bright ( \log L _ { Ly \alpha } / { [ erg s ^ { -1 } ] } > 43.4 ) and spatially-extended Ly \alpha emission , and present the photometric and spectroscopic properties of a total of seven LABs ; the two new LABs and five previously-known LABs at z = 5.7 - 6.6 .
The z70-1 LAB shows the extended Ly \alpha emission with a scale length of 1.4 \pm 0.2 kpc , about three times larger than the UV continuum emission , making z70-1 the most distant LAB identified to date .
All of the 7 LABs , except z49-1 , exhibit no AGN signatures such as X-ray emission , Nv \lambda 1240 emission , or Ly \alpha line broadening , while z49-1 has a strong Civ \lambda 1548 emission line indicating an AGN on the basis of the UV-line ratio diagnostics .
We carefully model the point-spread functions of the HSC images , and conduct two-component exponential profile fitting to the extended Ly \alpha emission of the LABs .
The Ly \alpha scale lengths of the core ( star-forming region ) and the halo components are r _ { c } = 0.6 - 1.2 kpc and r _ { h } = 2.0 - 13.8 kpc , respectively .
The average r _ { h } of the LABs falls on the extrapolation of the r _ { h } -Ly \alpha luminosity relation of the Ly \alpha halos around VLT/MUSE star-forming galaxies at the similar redshifts , suggesting that typical LABs at z \gtrsim 5 are not special objects , but star-forming galaxies at the bright end .