Description
Strong gravitational lensing by galaxy clusters can magnify the light
of background sources by factors of tens or more, pushing the current
observational limits towards the faint and distant Universe.
Thanks to coordinated programs using deep HST imaging (from large
programmes such as CLASH, Hubble Frontier Fields and RELICS) and
spectroscopy from MUSE in cluster fields, we can now probe
intrinsically faint, high redshift (out to z ~ 6.6) sources in detail
with potential impact on cosmic reionization.
It is worth noting that some of these clusters have been selected to
be observed with JWST under different GTO and ERS programmes (IDs
1176, 1199, 1208, and 1324).
In this talk I will show the current deep MUSE data from our ESO/VLT
programmes on a sample of clusters and the characterization in the
rest-frame UV of intrinsically faint Lyman-alpha emitters (with
Ly-alpha luminosities down to ~10^{41} erg/s) and Lyman-break galaxies
at high redshifts, that can be observed only thanks to the
gravitational lensing effect.
Special attention will be given to the observations of the HFF cluster
MACSJ0416, which has the deepest MUSE observations for a cluster
lensing up to date, overcoming the depth of the most expensive
observations on blank fields, such as the Hubble Ultra-Deep Field.
This will give us a glimpse and pave the way for the science that we
will be able to explore with the extremely large telescopes and JWST
in the near future.
