Dust in clusters: separating the contribution of galaxies and
  intracluster media
  We have analized a sample of 327 clusters of galaxies spanning the range
0.06-0.70 in redshift. Strong constraints on their mean intracluster emission
by dust have been obtained using maps and catalogs from the HERSCHEL HerMES
project; within a radius of 5 arcmin centered in each cluster, the 95% C.L.
limits obtained are 86.6, 48.2 and 30.9 mJy at the observed frequencies of 250,
350 and 500 $\mu$m. From these restrictions, and assuming physical parameters
typical of interstellar media in the Milky Way, we have obtained tight upper
limits on the visual extinction of background galaxies due to the intracluster
media: $A_V$(95% C.L.) <~$10^{-3}$ mags. Strong constraints are also obtained
for the mass of such dust; for instance using the data at 350 $\mu$m we
establish a 95% upper limit of $<10^9M_\odot$ within a circle with a radius of
5 arcmin centered in the clusters. This corresponds to a fraction of the total
mass of the clusters of $9.5\times 10^{-6}$, and indicates a deficiency in the
gas-to-dust ratio in the intracluster media by about three orders of magnitude
as regards the value found in the Milky Way. Computing the total infrared
luminosity of the clusters in three ranges of redshift (0.05-0.24, 0.24-0.42
and 0.42-0.71) and two ranges of mass ($<10^{14}$ and $>10^{14}M_\odot$)
respectively, a strong evolution of luminosity in redshift ($L\sim z^{1.5}$)
for both ranges of masses is found. The results indicate a strong declining in
star formation rate with time in the last $\sim 6$ Gyr.
