The Glow of Primordial Remnants

We determine the expected surface brightness and photometric signature of awhite dwarf remnant population, issued from primordial low-mass stars formed athigh redshifts, in today galactic halos. We examine the radial dependence ofsuch a contribution as well as its redshift dependence. Such a halo diffuseradiation is below the detection limit of present large field ground-basedsurveys, but should be observable with the HST and with the future JWSTproject. Since the surface brightness does not depend on the distance, theintegration of several galactic dark halos along the line of sight will raiseappreciably the chances of detection. Both the detection or the non-detectionof such a remnant diffuse radiation within relevant detection limits offervaluable information on the minimum mass for star formation in the earlyuniverse and on the evolution of the stellar initial mass function.Comment: 8 pages, 6 figures, to be published in Ap