Efficient detection of emission line galaxies in the Cl0016+1609 and
  MACSJ1621.4+3810 supercluster filaments using SITELLE
  We observe a system of filaments and clusters around Cl0016+1609 and
MACSJ1621.4+3810 using the SITELLE Fourier transform spectrograph at the Canada
France Hawaii Telescope. For Cl0016+1609 (z=0.546), the observations span an
11.8 Mpc x 4.3 Mpc region along an eastern filament which covers the main
cluster core, as well as two 4.3 Mpc x 4.3 Mpc regions which each cover
southern subclumps. For MACSJ1621.4+3810 (z= 0.465), 3.9 Mpc x 3.9 Mpc around
the main cluster core is covered. We present the frequency and location of the
emission line galaxies, their emission line images, and calculate the star
formation rates, specific star formation rates and merger statistics. In
Cl0016+1609, we find thirteen [OII]~3727 Angstrom emitting galaxies with star
formation rates between 0.2 and 14.0 M$_{\odot}$ yr$^{-1}$. 91$^{+3}_{-10}$%
are found in regions with moderate local galaxy density, avoiding the dense
cluster cores. These galaxies follow the main filament of the superstructure,
and are mostly blue and disky, with several showing close companions and
merging morphologies. In MACSJ1621.4+3810, we find ten emission line sources.
All are blue (100$^{+0}_{-15}$%), with 40$^{+16}_{-12}$% classified as disky
and 60$^{+12}_{-16}$% as merging systems. Eight avoid the cluster core
(80$^{+7}_{-17}$%), but two (20$^{+17}_{-7}$%) are found near high density
regions, including the brightest cluster galaxy (BCG). These observations push
the spectroscopic study of galaxies in filaments beyond z~ 0.3 to z~ 0.5. Their
efficient confirmation is paramount to their usefulness as more galaxy surveys
come online.
