  We present results of our intermediate-band optical imaging survey for
high-$z$ Ly$\alpha$ emitters (LAEs) using the prime focus camera, Suprime-Cam,
on the 8.2m Subaru Telescope. In our survey, we use eleven filters; four
broad-band filters ($B$, $R_{\rm c}$, $i^\prime$, and $z^\prime$) and seven
intermediate-band filters covering from 500 nm to 720 nm; we call this imaging
program as the Mahoroba-11. The seven intermediate-band filters are selected
from the IA filter series that is the Suprime-Cam intermediate-band filter
system whose spectral resolution is $R = 23$. Our survey has been made in a
$34^\prime \times 27^\prime$ sky area in the Subaru XMM Newton Deep Survey
field. We have found 409 IA-excess objects that provide us a large photometric
sample of strong emission-line objects. Applying the photometric redshift
method to this sample, we obtained a new sample of 198 LAE candidates at $3 < z
< 5$. We found that there is no evidence for evolution of the number density
and the star formation rate density for LAEs with $\log L({\rm Ly}\alpha) ({\rm
erg s^{-1}}) > 42.67$ between $z \sim 3$ and 5.

Astrophysics