Abstract details

We present new results following up on our deep near-IR imagingof the strong lensing clusters Abell 1835 and AC114, which has allowed us to identify 13 star forming galaxy candidates at $z \ga$ 7 (Richard et al.\ 2006, A\&A in press, [astro-ph/0606134]). Our previous optical and near-IR observations have now been complemented by new deep imaging with ACS/HST in the z$_{850}$ band, with Spitzer IRAC and MIPS at longer wavelengths, and with new Chandra observations.The ACS images confirm all of our high-$z$ candidates as optical drop-out sources. Based on these new data we will present a re-analysis of our high-$z$ candidates and the constraints on the star formation history at $z \sim$ 6--10. Based on detailed SED modeling, using spectral templates of Bruzual \& Charlot, Schaerer(starburst), Maraston (including TP-AGB stars) and others, we will quantify their photometric redshifts, compare them with our spectroscopic observations, and we will discuss the properties of the individual objects.