  We determine the expected surface brightness and photometric signature of a
white dwarf remnant population, issued from primordial low-mass stars formed at
high redshifts, in today galactic halos. We examine the radial dependence of
such a contribution as well as its redshift dependence. Such a halo diffuse
radiation is below the detection limit of present large field ground-based
surveys, but should be observable with the HST and with the future JWST
project. Since the surface brightness does not depend on the distance, the
integration of several galactic dark halos along the line of sight will raise
appreciably the chances of detection. Both the detection or the non-detection
of such a remnant diffuse radiation within relevant detection limits offer
valuable information on the minimum mass for star formation in the early
universe and on the evolution of the stellar initial mass function.
