  We present integral-field spectroscopic observations with the VIMOS-IFU at
the VLT of fast (2000-3000 km/s) Balmer-dominated shocks surrounding the
northwestern rim of the remnant of supernova 1006. The high spatial and
spectral resolution of the instrument enable us to show that the physical
characteristics of the shocks exhibit a strong spatial variation over few
atomic scale lengths across 133 sky locations. Our results point to the
presence of a population of non-thermal protons (10-100 keV) which might well
be the seed particles for generating high-energy cosmic rays. We also present
observations of Tycho's supernova remnant taken with the narrow-band tunable
filter imager OSIRIS at the GTC and the Fabry-Perot interferometer GHaFaS at
the WHT to resolve respectively the broad and narrow H\alpha\ lines across a
large part of the remnant.
